Open Mind

Open Thread #15

August 5, 2009 · 242 Comments

For discussion of things climate-related which are off topic for other threads.

Categories: Global Warming
Tagged:

242 responses so far ↓

  • Tom Fiddaman // August 5, 2009 at 6:05 pm

    Anyone seen any intelligent critique of Lindzen’s redo of his ERBE paper?

    http://wattsupwiththat.com/2009/07/23/new-paper-from-lindzen/
    http://www.leif.org/EOS/2009GL039628-pip.pdf

    On the determination of climate feedbacks from ERBE data

    Richard S. Lindzen and Yong-Sang Choi

    Revised on July 14, 2009 for publication to Geophysical Research Letters

    Abstract
    Climate feedbacks are estimated from fluctuations in the outgoing radiation budget from
    the latest version of Earth Radiation Budget Experiment (ERBE) nonscanner data. It
    appears, for the entire tropics, the observed outgoing radiation fluxes increase with the
    increase in sea surface temperatures (SSTs). The observed behavior of radiation fluxes
    implies negative feedback processes associated with relatively low climate sensitivity.
    This is the opposite of the behavior of 11 atmospheric models forced by the same SSTs.
    Therefore, the models display much higher climate sensitivity than is inferred from
    ERBE, though it is difficult to pin down such high sensitivities with any precision.
    Results also show, the feedback in ERBE is mostly from shortwave radiation while the
    feedback in the models is mostly from longwave radiation. Although such a test does not
    distinguish the mechanisms, this is important since the inconsistency of climate
    feedbacks constitutes a very fundamental problem in climate prediction.

  • dko // August 5, 2009 at 6:37 pm

    UP!

    http://www.remss.com/data/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_2.txt

    For the last several months a gap has been growing between ground- and satellite-based anomaly data. Now, RSS has effectively eliminated that gap with the release of its July numbers.

    Adjusting to the same baseline (Jan 79 to Dec 98), the June global numbers were: GISS, 0.394; HadCRUT, 0.348; NCDC, 0.364. RSS has revised its June global value from 0.075 to 0.081 and is reporting 0.392 for July — a jump of more than 0.3 C in one month.

    UAH reported 0.01 for June, which was embraced by the anti-warming crowd. The next few days should be interesting….

  • Ray Ladbury // August 5, 2009 at 6:52 pm

    You mean other than the fact that if Lindzen uses data corrected for orbital decay, the effect goes away?

    http://chriscolose.wordpress.com/2009/03/31/lindzen-on-climate-feedback/

  • Tom Fiddaman // August 5, 2009 at 7:18 pm

    Ray – I haven’t had time to track sources, but it looks like the new version uses the corrected data, so that particular critique no longer applies. At least, Lindzen & Choi cite Wong et al. 2006.

    Other things look fishy to me – his treatment of deltaT intervals in the scatterplots, for example. Also, eyeballing the AMIP model output, I’d speculate that they don’t all include volcanic forcing.

  • Mark // August 5, 2009 at 7:20 pm

    Tom, this would require intelligence in the redone paper.

    Like Plimer’s “The sun is made of Iron!”, there are some things that arguing against has no option but to avoid intelligence.

    It’s a lot easier to say “there is no gravity” than to prove there is intelligently.

    As an example.

  • dhogaza // August 5, 2009 at 7:30 pm

    UAH is at 0.41 for July.

  • Tom Fiddaman // August 5, 2009 at 9:30 pm

    I wouldn’t put Lindzen and Plimer in the same bucket. If there’s no intelligence at all in the paper, it should be easy to show why. I think there are problems with Lindzen & Choi, but they’re more subtle than the usual rubbish.

  • David B. Benson // August 5, 2009 at 9:53 pm

    Mark // August 5, 2009 at 8:32 am — Continuing from Open Thread #14, it is believed that Venus retains a molten core; it has techtonics alright, just not plate techtonics.

    The central point I am making is that the somewhat different chemical composition (and mass) of Venus and post-impact Terra resulted in dramatically different geologic histories, only one with (surviving) abiogenesis.

  • Zeke Hausfather // August 5, 2009 at 10:02 pm

    Tamino,

    I’m curious of your take on Scafetta’s criticism of Benestad and Schmidt here: http://climatesci.org/2009/08/03/nicola-scafetta-comments-on-solar-trends-and-global-warming-by-benestad-and-schmidt/

    My understanding of wavelet transforms is rather painfully limited, unfortunately, so I’m not sure how to evaluate their argument.

  • Nathan // August 5, 2009 at 11:40 pm

    MArk, without water Plate tectonics wouldn’t happen on an Earth-like Planet. There are theories that it started on Venus, but once it lost it’s water it stopped.

    Plenty of references on the Wikipedia page.

  • Michael hauber // August 6, 2009 at 12:09 am

    One thing to watch out for in Lindzen’s paper is that the analysis applies to the tropics only – 1/3rd of the earth. There is then a quick reference to one of his earlier papers (the IRIS one from memory) which proves that the same result applies to the other 2/3rds.

    Also I see the tropospheric hotspot issue has raised its head again. Does anyone know what would be the implications if the hotspot really is missing? From my understanding of why the tropospheric hotspot is there this would mean that the tropical atmosphere would become much more unstable as this would mean the surface is warming up, but the middle troposphere is not warming up fast enough to maintain atmospheric stability, and the result would be an increase in convection and severe weather in the tropics?

  • chriscolose // August 6, 2009 at 1:12 am

    Lindzen now uses Edition3 data but not the rev1 corrections. I’m not sure of any other potential problems (haven’t looked at it in too much detail, not sure if I will) but Wong et al 2006 reach a different conclusion on model-obs comparison.

  • chriscolose // August 6, 2009 at 1:18 am

    Michael,

    The implications of a missing hotspot are kind of large, but it has little to do with the attribution of warming to CO2. In fact, it would hint at a slightly larger climate sensitivity since the magnitude of the lapse rate feedback would be less negative.

    The hot spot is expected from the thermodynamics of the moist adiabat. We see this maintained in response to ENSO, the solar cycle, etc and not much reason to expect a different picture from CO2. You’re right about changes in moist stability: Hurricane intensity for instance is largely related to the gradient between the surface and the outflow temperature, so taking the atmosphere off the moist adiabat could have implications for higher intensity (Isaac Held who has recently posted here on the water vapor thread has some work on this).

  • Deep Climate // August 6, 2009 at 2:55 am

    dko said:

    For the last several months a gap has been growing between ground- and satellite-based anomaly data. Now, RSS has effectively eliminated that gap with the release of its July numbers.

    dhogaza said:

    UAH is at 0.41 for July.

    That’s the biggest month over month rise ever in UAH LT, and also one of the largest in RSS.

    I’m sure we’ll see a rise in the surface series too, but probably somewhat smaller.

    As for the “growing gap” with surface data sets, there does seem to be an annual cycle in the difference between UAH (and to some extent RSS) and the surface sets.

    Here’s a graph based on the difference between the UAH and RSS LT data sets and surface set average (i.e. average of NASA, NOAA and HADCru, baselined to 1979-1998).

    There does seem to be an annual cycle in recent years, with a peak early in the year and a trough towards mid-year (especially pronounced in June, 2009).

    http://deepclimate.files.wordpress.com/2009/08/uah-rss-surface-diff.gif

  • Hank Roberts // August 6, 2009 at 3:47 am

    http://www.nap.edu/catalog.php?record_id=10610

    Fair Weather: Effective Partnerships in Weather and Climate Services
    For example, DOD collects weather data to support military operations, …
    For example, commercial airlines collect temperature, humidity, and wind data and …

    Anyone know whether this is available?

  • dhogaza // August 6, 2009 at 4:20 am

    For a good time, go to WUWT, and watch the denialists trying to digest the fact that UAH shows a huge uptick in July despite all the WUWT denizens posting that their local weather is record-setting cold.

    It’s effing hilarious.

  • cce // August 6, 2009 at 4:45 am

    Speaking of the “hot spot”, I compiled this list of papers that do detect enhanced tropical troposphere warming in observational records, in contrast to the oft-repeated notion that “none exist.”

    Haimberger, Tavolato, and Sperka (2008)
    “In the tropical upper troposphere, where the predicted amplification of surface trends is largest, there is no significant discrepancy between trends from RICH–RAOBCORE version 1.4 and the range of temperature trends from climate models. This result directly contradicts the conclusions of a recent paper by Douglass et al. (2007).”
    http://ams.allenpress.com/archive/1520-0442/21/18/pdf/i1520-0442-21-18-4587.pdf

    Sherwood et. al. (2008)
    “Insofar as the vertical distributions shown in Fig. 3 are very close to moist adiabatic, as for example predicted by GCMs (Fig. 6), this suggests a systematic bias in at least one MSU channel that has not been fully removed by either group [RSS & UAH].”
    http://web.science.unsw.edu.au/~stevensherwood/sondeanal.pdf

    Allen & Sherwood (2008)
    “The observations at the surface and in the troposphere are consistent with climate model simulations. At middle and high latitudes in the Northern Hemisphere, the zonally averaged temperature at the surface increased faster than in the troposphere while at low latitudes of both hemispheres the temperature increased more slowly at the surface than in the troposphere.”
    http://www.nature.com/ngeo/journal/v1/n6/abs/ngeo208.html

    Fu & Johanson (2005)
    “We find that tropospheric temperature trends in the tropics are greater than the surface warming and increase with height.”
    http://www.atmos.washington.edu/~qfu/Publications/grl.fu.2005.pdf

    Vinnikov et. al. (2006)
    “At middle and high latitudes in the Northern Hemisphere, the zonally averaged temperature at the surface increased faster than in the troposphere while at low latitudes of both hemispheres the temperature increased more slowly at the surface than in the troposphere.”
    http://www.atmos.umd.edu/~kostya/Pdf/VinnikovEtAlTempTrends2005JD006392.pdf

  • dko // August 6, 2009 at 6:08 am

    dhogaza said:
    For a good time, go to WUWT, and watch the denialists trying to digest the fact that UAH shows a huge uptick in July despite all the WUWT denizens posting that their local weather is record-setting cold.

    If global temperature must rise, at least it’s happening while the S-U-N cannot be blamed. We will soon have enough data to prove that sunspots lag global warming….

  • Michael hauber // August 6, 2009 at 6:26 am

    So why should the hot spot limited to the tropics only? Is this because the Hadley cell is expanding to a larger size, but also losing intensity? i.e less downwelling in non tropical areas, so less stability (but still not unstable on average). Would this factor lead to increased thunderstorm/other severe weather activity in the subtropic and temperate zones?

  • Mark // August 6, 2009 at 7:19 am

    “There are theories that it started on Venus, but once it lost it’s water it stopped. ”

    Ergo, *if* plate tectonics IS a requirement for life, then Venus could have had it.

    All we have on the scarcity of life are the FACT that our two neighboring planets could have had them but do not *at this time*.

    This doesn’t counter in any reliable way the fact that the constituents for creating life are quite abundant.

    Which was David’s proposition, that life is unlikely because Venus and Mars don’t have any.

    Tenuous at best.

  • Ray Ladbury // August 6, 2009 at 12:38 pm

    Dhogaza, I suppose that a trip over to Watts-up-’is-arse might actually be informative (local temperatures, etc.) if you couldn’t get the Weather Channel. After all, he’s got hundreds of Watt-bots willing to brave ticks, sunstroke and sprained ankles to gather irrelevant data. However, micro-Watt’s success merely illustrates that idiots are useful only if your goal is to confuse things.

  • Nick Barnes // August 6, 2009 at 12:53 pm

    Over on RC, BobFJ has an interesting point about the retreat of the Jakobshaven glacier: that it hardly retreated at all between 1964 and 2001, when global temperatures were rising quite steeply, but that since 2001 it has retreated dramatically (this was sparked off by observations from myself and Tenney Naumer that it has continued retreating since 2006).
    Anyway, I find the glacier’s behaviour quite easy to understand but quite difficult to explain. Anyone want to think about it further and pitch in over at RC?

  • Hank Roberts // August 6, 2009 at 3:56 pm

    “global temperatures” usually means air temperature. We don’t yet have enough measurements of ocean temps. Anything at the level of the ocean is mostly going to be melting when _relatively_ warmer water reaches it; for glaciers that would be melting back underneath, I think. Lots of work being done on that, including sending remotely operated vehicles up into the melting spaces.

  • TCO // August 6, 2009 at 3:56 pm

    I been reading QED in the bathtub. Feynman rocks. I like him better than the denialist old fart yuck yucks…or the policy freak alarmists fresh from ELF meetings.

  • Gavin's Pussycat // August 6, 2009 at 4:36 pm

    > So why should the hot spot limited to the tropics only?

    Because tropical air contains the most water vapour to start with.

  • Ray Ladbury // August 6, 2009 at 4:53 pm

    TCO, I agree on Feynman. What I like about him is that he not only communicates the subject matter of science, but also comes closer than anyone else to communicating what it is like to do science.

  • dhogaza // August 6, 2009 at 7:13 pm

    Ray:

    TCO, I agree on Feynman.</blockquote
    You guys just like feynman because he wrote an essay on picking up girls.

  • John Mashey // August 6, 2009 at 8:51 pm

    I’ve been studying the latest Singer/Happer exercise in anti-science PR, i.e., the Open Letter to American Physical Society. I think there is ~zero chance APS will switch to the position they espouse, but obviously, the letter is for others’ consumption. Their May list had 54 people, a 6-person subset wrote a letter to Nature, and the latest list has 61, although Lewis was omitted (likely by accident), so that’s 62 altogether. About a quarter were familiar to me, but most weren’t, so it led to a nice exercise in social network analysis.

    In one amusing corner, we find 3 senior faculty associated with astronautics at University of Southern California, none of whom who’ve ever published peer-reviewed work on cliamte scinice that I can find:

    - have signed the petition, essentially declaring the last 30 years of climate science non-existent.

    - but are part of a USC effort seeking research funding from California and the Federal government for … climate research, because they can do it better than traditional climate science departments.

    The petition lists the following:

    1) Mike Gruntman
    Professor of Astronautics
    University of Southern California
    Author, Blazing the Trail. The Early History of Spacecraft and Rocketry (AIAA)
    Luigi G. Napolitano Book Award (International Academy of Astronautics) 2006
    Member American Geophysical Union, Associate Fellow AIAA

    2) Joseph A. Kunc
    Professor, Physics and Astronomy
    University of Southern California
    Fellow APS

    3) Donald Rapp
    Chief Technologist, Mechanical and Chemical Systems,
    Jet Propulsion Laboratory (retired)
    Professor of Physics and Environmental Engineering, University of Texas (1973-1979)
    Author, “Assessing Climate Change” and “Ice Ages and Interglacials” (Springer-Verlag)
    Fellow APS

    In more detail, that’s:
    1) Mike Gruntman.

    2) Joseph Kunc.

    3)Donald Rapp. He retired from JP in 2002, and is now a Research Professor @ USC. See especially his comment:

    “I have surveyed the wide field of global climate change energy and I am familiar with the entire literature of climatology.”

    He has written a book, of which Google BOoks provides an adequate sample. Hint: the first words are “Global warming alarmists believe…”

    Now, see: USC Climate Change Research Group (CCRG), which says:

    “Traditional oceanographic or atmospheric programs are not necessarily well-equipped for such a challenge. USC is, however, well positioned to take a lead in this evolving science by building upon its existing strengths in cyber infrastructure and programs in climate research, physics and engineering.”

    “We propose to formalize our interdisciplinary program in climate change research at USC into the USC Climate Change Institute. The framework of the Institute will revolve around national and California climate change research programs (see Appendix), which are the expected sources of funding”

    Gruntman, Kunc, and Rapp are all key members of this group…

  • Barton Paul Levenson // August 6, 2009 at 9:31 pm

    dhogaza writes:

    You guys just like feynman because he wrote an essay on picking up girls.

    While I admire Feynman’s popular science writing, it didn’t make me like him to learn that he advocated sexual success through treating neurotic, self-loathing women at bars like crap.

  • chriscolose // August 6, 2009 at 9:57 pm

    Michael Hauber,

    You get a hotspot in the tropics where moist convection is large. At the poles the situation is reversed and you expect more surface amplification.

  • Hank Roberts // August 6, 2009 at 10:25 pm

    > the first words are “Global warming
    > alarmists believe…”
    >
    > Now, see: USC Climate Change
    > Research Group (CCRG)

    Well, sure, if there’s money on offer, they’ll make a pitch to get it. First line of defense is to keep any funds out of the hands of anyone who might do something with it.

  • David B. Benson // August 6, 2009 at 11:50 pm

    Mark // August 6, 2009 at 7:19 am — Since we don’t know all the requirements for abiogenesis, to state that the constituents are abundant has no empirical basis.

    I simply take the position that the totality of the requirements are met only stupendously rarely. The reasons for this position don’t seem very related to climate so I’ll not go inot that. I only brought up these matters since the Fermi Paradox had come up earlier.

  • Kipp Alpert // August 7, 2009 at 3:04 am

    Ray Ladbury:How ya doin. We know that the signal for Global Warming started shortly after the industrial Revolution. Could an event like Mt.Pinatubo, and the subsequent cooling be considered a cooling trend of any kind. Obviously its not like a La Nina. I have been busy lately but have started to come at my Atmospheric Principles study from Chemistry.
    Whatever works?

  • Hank Roberts // August 7, 2009 at 3:12 am

    http://scholar.google.com/scholar?hl=en&scoring=r&q=Saturn+moon+titan+chemicals

    And in weather news:

    http://www.cnn.com/video/#/video/weather/2009/08/06/vo.ak.waterspout.cnn

  • Kipp Alpert // August 7, 2009 at 3:52 am

    Ray Ladbury:I have come to the understanding that deniers, or those people who find their emotional outlet in denying Global Warming, is just another way for the fringe to call America their own. Their America has a white face, is Christian conservative, anti government, and do consider people farther from themselves or their own State, as aliens. Either Illegal or extraterrestrial. They talk about God and Country, yet the way they consider people with opposing views as Evil, and their Country being taken over by the socialists, I wonder how much they love at all, and how dangerous they are, in our free country. The only ironic thing about this, is that they are cutting off their hands to spite their face. So a denier is a hater in sheep’s clothing, and their Shepard isn’t Jesus but Racial
    and anti government morons like Tony Watts, Glenn Beck, and finally Adolf. My grandmother in the second world war lost seventeen relatives
    too ignorance like this. As my son said, many of us are just waiting for our bonus, to live out our lives so comfortably as consumers, so that his
    generation can figure out how to put everything right again. It’s ironic that our country be the last to suffer our dreadful future. Kipp

  • cce // August 7, 2009 at 4:50 am

    Another truly incompetent post, based on a bad press release:
    http://wattsupwiththat.com/2009/08/06/long-debate-ended-over-cause-demise-of-ice-ages-solar-and-earth-wobble/

    And I’d like to know which scientists have suggested that ice ages are triggered by CO2 and not orbital variations, as the press release states. Not the ones represented by the IPCC, that’s for sure. But reading what the IPCC says is just too hard.

    On a related topic. Leif, I know you don’t get along with a lot on the “consensus” side (cough::tamino::cough) but really. Take a long hard look at who you’re hanging with.

  • Ray Ladbury // August 7, 2009 at 12:09 pm

    Hi Kipp, Good to see you are still about. I’ve been buried under the day job of late–papers and conferences on top of many, many projects. People tend to fear change–and not without reason. Change often makes things worse for many. The problem is that change is inevitable here. The only choice is whether we will try to take control of the change. You can see why many distrust such control–they are afraid that those exercising control will try to turn the situation to their advantage. That is not an unreasonable fear.
    So we have a perfect storm: The biggest physical threat to continued human civilization coincides with the moment when many have lost faith in the very institutions we have to confront that threat.
    However, the prospects of what will happen if we do not take control of our economy are truly horrifying. What this means is that the change we will need is even more fundamental than simply changing the energy infrastructure. We are also going to have to develop institutions and processes that facilitate trust.

  • Tom Fiddaman // August 7, 2009 at 5:49 pm

    News flash: Lomborg switches sides
    http://www.ft.com/cms/s/0/5ebdb666-82a5-11de-ab4a-00144feabdc0.html
    Well, a little bit anyway.

  • Kipp Alpert // August 7, 2009 at 6:08 pm

    Ray Ladbury; Yes! If you are talking about a small dose of government control specifically we the people, not just the corporations. The capitalists have really taken the people for a ride, and they are against their fellow Americans
    whether the people see this or not. I grew up in Darien, Ct., where they shot the film “stepford wives” and it is really not far off the mark. I can’t tell you the endless parties that I had to attend(for my business) and sit around and listen to grown men only talk about Wall Street.
    Their wives dutifully joined there own group conspiring to take over the all men’s lounge at the Country Club. Well, I hope your wife is well, and I haven’t forgotten my offer, just am in between Cameras, trying the Hasselblad back, on an older body. Any thing is better than 35mm, and they are starting to come out with more affordable two and a quarter inch, with twice the depth of field etc. Keep up the good fight. KIPP

  • Hank Roberts // August 7, 2009 at 6:22 pm

    > switches tack

    Well, no, it’s still “anything but controlling fossil fuel use by the rich” …

  • dhogaza // August 7, 2009 at 7:27 pm

    Well, no, it’s still “anything but controlling fossil fuel use by the rich” …

    Exactly, it’s the “well, OK, it’s true but adapting and mitigating rather than cutting emissions is the only thing to do” tactic.

  • John Mashey // August 7, 2009 at 7:31 pm

    Tom: re Lomborg

    I don’t think so.
    Recall, from that piece:

    “He is concerned that the United Nations-led consensus that a climate treaty must focus on cuts in greenhouse gas emissions from rich countries is mistaken.”

    Now, try Lomborg and playing the long game, and see if you think Lomborg’s goal has changed in the slightest. He has *always* been more sophisticated in his approaches than many others.

  • Adam // August 7, 2009 at 8:04 pm

    cce – The Daily Telegraph misrepresented a paper about ice ages and CO2 to state exactly that not too long ago. IIRC the lead author of the paper wrote to the paper (not published) and even tried posting comments to it (deleted) to try and correct the article. The article went uncorrected (it may have been deleted, not sure). This may be what they’re referring to.

    Don’t have a reference to hand but Deltoid or “Bad Science” should have articles on it. Else a web search should throw it up.

  • dhogaza // August 9, 2009 at 9:26 pm

    It’s weather, not climate …

    But it’s quite amazing …

    • suricat // August 10, 2009 at 2:07 am

      dhogaza: “Its weather, not climate . But it’s quite amazing …”

      Yes it is isn’t it (not climate, but amazing). However, they only jumped for the first thunderclap and the whole thing should’ve lasted longer. In the words of Bernard Mathews, it was bootiful!

      An excellent representation of the natural phenomenon that makes nature so hard to describe. Loved it, and thank you for this.

      Best regards, suricat.

      • suricat // August 10, 2009 at 2:29 am

        dhogaza: “they only jumped for the first thunderclap”

        3 thunderclaps and 3 jumps. The choreography was correct, but it must have been the camera angle that made me think otherwise on the first take.

        Best regards, suricat.

  • freemike // August 9, 2009 at 9:43 pm

    Anyone seen this website and claim that ice core samples prove co2 is not powerful climate driver that ‘alarmist’ make it out to be.

    First thing I noticed was that it was a website not a peer-reviewed paper but I’d like more ammo to return and fight. thanks.

    http://www.co2science.org/articles/V6/N26/EDIT.php

    [Response: The "co2science" website is one of the most heinous denialist sites on the web -- and that's saying a lot.

    They're way beyond hope. I suggest the most effective strategy is to give them as little attention as possible.]

  • Michael hauber // August 9, 2009 at 11:08 pm

    Freemike, Skeptical Science is a good web page for debunking most common myths on climate. For Co2 – temp lag in the ice cores see in particular http://www.skepticalscience.com/co2-lags-temperature.htm

  • Hank Roberts // August 9, 2009 at 11:39 pm

    You need to study the science yourself for a while, if you want more than just to be in an argument with people about this.

    Once you’ve read the material available well enough to have asked some smart questions of the scientists,* impressed them that youv’e read enough to ask a smart question and seem really interested, and made more progress, you’ll find you’re developing the ability to explain things a little bit (mostly by knowing how to look up the science and give people good pointers so they can read for themselves).

    Then they’ll eventually ask _you_ smarter questions.

    Take your time. Rushing to the front lines without learning the material just teaches the controversy.
    —–
    * Once you’ve read a few dozen papers, you’ll have figured out ways to ask the scientists questions.

  • Hank Roberts // August 10, 2009 at 12:39 am

    PS, this applies equally well to climate questions:

    http://scienceblogs.com/pharyngula/2009/08/the_dilemma_of_the_anti-creati.php

    See the link for the full piece there. He begins:

    “Sean Carroll has a very interesting post on appropriate arguments — he illustrates it with this grid of disputation.
    http://scienceblogs.com/pharyngula/upload/2009/08/grid-of-disputation.jpeg

    The context is the recent bloggingheads between … an irredeemable kook … well into the Red Zone of Crackpots in the diagram, yet none of his lunacy was engaged — he was treated as if he were a sensible person, with meritable ideas deserving serious consideration, when nothing could be further from the truth.

    Sean makes a somewhat different point: that it is a bad idea for critics to engage the very worst of the opposition, and to then congratulate themselves on their success in fighting off the enemy. We should be wrestling with the Green Zone of Worthy Opponents, not wasting our time with crackpots!….”

  • Ray Ladbury // August 10, 2009 at 1:37 am

    OK, Hank, I give. Where are the worthy denialists? I’ve been looking for 5 years, and all I’ve found are ignoramuses and crackpots.

  • John Mashey // August 10, 2009 at 6:54 am

    Ray & Hank:
    I’ve been a-researching on that APS Open Letter.
    Any ideas on Sultan Hameed @ Stony Brook? I have one or two, but am still puzzled.
    Most of others are pretty clear; he seems the only maybe-plausible -real climate scientist of the group, so I’m slightly puzzled.

  • Barton Paul Levenson // August 10, 2009 at 11:24 am

    freemike,

    A quick overview is here:

    http://BartonPaulLevenson.com/Lag.html

  • bjchip // August 10, 2009 at 11:42 am

    I have seen the claim that the CO2 is already so concentrated in the atmosphere column, that further absorption of radiation is not possible, even if the concentration were doubled.

    Up to now I have been responding that the warming happens lower in the column, where other heat transfer mechanisms occur, up to and including the molecules being absorbed by the ocean itself.

    The problem with this answer is that it isn’t something I can back up by pointing at work done by someone who actually knows what the hell is going on :-)

    I’m bright enough to know I could be wrong or overlooking something, so I figured I’d ask here. What answer would you guy’s give?

    Thank you

    BJ

  • Ray Ladbury // August 10, 2009 at 1:54 pm

    BJCHIP,
    A good treatment here:
    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

    and

    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument-part-ii/

    Basically, it comes down to the fact that the absorption lines are thick-tailed. This is why the increase in forcing is logarithmic in concentration rather than linear.

  • Ray Ladbury // August 10, 2009 at 1:57 pm

    Hi John,
    Hameed seems to be one of the “It’s the sun” crew. His research isn’t particularly broad, so I don’t think he fully understands all of the science. I’d describe him more as an “atmospheric scientist” rather than a climate scientist.

  • Aslak // August 10, 2009 at 2:26 pm

    @bjchip: I’ve seen those claims too. I think that it is not made by any of ‘the professional skeptics’, but only by very few crazy blog commenters. I doubt that you can convince these commenters.

    Here’s a simple argument that I think that most people would understand.
    CO2 (like other GHGs) has spectral windows where it is transparent and others where it absorbs nearly all radiation. In between there are flanks where the absorbtion is incomplete. Adding additional CO2 would obviously have add to its absorbtion in these spectral bands.

    But I think that your argument about the whole column is also very important.

    Maybe you can also simply point to this transmission spectrum of earth: http://www.nature.com/nature/journal/v459/n7248/full/nature08050.html
    CO2 is clearly not blocking everything it possibly can.

  • Phil. // August 10, 2009 at 2:45 pm

    bjchip // August 10, 2009 at 11:42 am | Reply

    I have seen the claim that the CO2 is already so concentrated in the atmosphere column, that further absorption of radiation is not possible, even if the concentration were doubled.

    This claim is false, what happens as the concentration increases is that although the center of some of the absorption lines becomes saturated the line itself becomes broader thereby increasing the total absorption. This results in an approximately logarithmic increase in absorption in our atmosphere. Google ‘collisional broadening’ and ‘Voigt profile’ for more information.

    Here’s an example of the CO2 spectrum for a doubling for the whole band (too poorly resolved to see individual lines) and a detail of the edge.

    http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2spectra.gif

  • Kevin McKinney // August 10, 2009 at 3:18 pm

    BJ, you might try this; it’s a couple of years old, but then the argument goes back to about 1904 anyway.

    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

  • Hank Roberts // August 10, 2009 at 3:33 pm

    Chuckle. Where are they?

    Ray, I have a simple criterion — if Tamino, or the RC contributors, pass a posting by someone, whatever I think of it, it’s so worth responding too. I’ll trust these people who really know the science to pick the “teachable moment” posts.

    I’m not replying to the person or evaluating their sincerity or sense; just replying to the posting.

  • jyyh // August 10, 2009 at 3:33 pm

    Phil said: “This results in an approximately logarithmic increase in absorption in our atmosphere.”

    And probably the increasing temperature leads to stronger circulation in the atmosphere which distributes CO2 better than before.

  • Mark // August 10, 2009 at 4:10 pm

    David: “Since we don’t know all the requirements for abiogenesis, to state that the constituents are abundant has no empirical basis.”

    We know what the constituents are.

    To deny that is to deny we know biology.

    There may be other chemistries for life, but the ones we DO know about ARE abundant.

    That they may require the right ***conditions*** to turn these chemicals into replicating life does NOT change the fact that the necessary ingredients are abundant.

  • Hank Roberts // August 10, 2009 at 6:47 pm

    jyyh, why do you say “stronger circulation” — I used to think that but I’ve been convinced there’s much more involved than just adding heat to the heat engine; we’re also reducing the ability of the heat engine to _remove_ heat from the cold side, and that reduces its efficiency.

    Got a source?

    Have a look at this:

    Robust responses of the hydrological cycle to global warming

    http://courses.eas.ualberta.ca/eas570/h2o_cycle_global_warming.pdf

    IM Held, BJ Soden – Journal of Climate, 2006
    ” … a reduction in convective mass flux with increasing temperature. …”

    “… In many popular, and in some scientific, discussions of global warming, it is implicitly assumed that the atmosphere will, in some sense, become more energetic as it warms. By the fundamental measure provided by the average vertical exchange of mass between the boundary layer and the free troposphere, the atmospheric circulation must, in fact, slow down. ”

    Cited by 158: http://scholar.google.com/scholar?cites=16631860617377423889&hl=en

    Dr. Held dropped in here briefly; I hope we hear more scientists doing that sort of visit to remind us to pay better attention to their published work.

  • jyyh // August 10, 2009 at 7:22 pm

    Thank you Hank Roberts, good point… just mistook the stronger hurricanes argument with stronger circulation in general. But if the circulation weakens wouldn’t it mean that the CO2 doesn’t reach poles so well thus letting the winter nights do their job better (i.e cool the earth) than today ? OK, that was a lame question, of course there are the tundra deposits of carbon coming out. Will the warming be at some point be strongest in midlatitudes? So easy to lose the whole picture.

  • Hank Roberts // August 10, 2009 at 8:04 pm

    To do: see if changes in fossil fuel use shows up in the CO2 measurements over the coming year or so.

    http://media.npr.org/assets/blogs/planetmoney/images/2009/08/worldtrade_custom.jpg?s=3

    http://www.npr.org/blogs/money/2009/08/chart_the_collapse_in_global_t.html
    —-excerpt follows—–

    The chart above shows that we’re living through the only major, sustained fall in global trade since 1970. Carl Weinberg of High Frequency Economics notes that French exports are down 18.7 percent, after a 24.7 percent year-over-year decline just a couple of months back. Monthly reports on German exports document declines of 24.8 percent and 29 percent. Australia, which has been feasting on its export economy, is down 14.7 percent.

    “Behind each story lies a catastrophic decline in gross exports,” Weinberg writes. The IMF data on exports track a 36 percent fall from the peak of $1.5 trillion in July 2008. “We have never experienced anything like this in our lifetimes. Neither, quite frankly, did we ever think we would.”

  • David B. Benson // August 10, 2009 at 10:18 pm

    Mark // August 10, 2009 at 4:10 pm — We know the constitents for current lifeforms, highly evoled, all of them. We simply don’t know the constituents for the very first life form. It is premature to assert that CNOPKSH sufficed.

  • Hank Roberts // August 10, 2009 at 10:22 pm

    jyyh: I pasted your question into Google for you.

    http://www.google.com/search?q=how+does+CO2+spread+in+the+atmosphere%3F

  • Hank Roberts // August 10, 2009 at 10:30 pm

    “… familiar with the entire literature of climatology …”

    He’s just begging for the Leun treatment:

    http://www.balloon-juice.com/?p=10646

  • Hank Roberts // August 10, 2009 at 11:52 pm

    WHAT’S NEW Robert L. Park Friday, 6 Aug 09 Washington, DC…

    … This week I got an Aug 4 article from Newsmax.com: Record Lows Dispel Global Warming Myth by Phil Brennan. Apparently, the author is unable to distinguish between weather and climate. Ordinarily, I would prefer waterboarding to reading this libertarian rag, but it was sent by a Nobel prize-winning physicist. The first words below the title were “Former Vice President Al Gore, father of the great global warming hoax…” I’m pretty sure Al Gore did not invent global warming, but these people are consumed by their hatred for Gore. I could guess what was coming next: A list of American cities that have been experiencing unusually low temperatures this summer. Seattle and Portland were having their highest temperature ever, which also has nothing to do with global warming; of course, they were not mentioned. ….

    https://listserv.umd.edu/cgi-bin/wa?A0=bobparks-whatsnew&D=1&F=P&H=1&O=D&T=0

  • Kevin McKinney // August 11, 2009 at 2:57 am

    No cherries in the Northwest, I guess. . . .

  • JCH // August 11, 2009 at 3:10 am

    I have so much fun reading this blog, but really can’t say much because I am not trained in these areas.

    But anyway, I have been researching the “backdoor” payment of 12.9 (media number) billion to Goldman Sachs. Goldman was due 18.8 billion from AIG:

    5.9 billion (collateral posted pre-BO)
    2.5 billion (post BO collateral)
    5.6 billion (Fed purchase of Maiden Lane)
    4.8 billion (non CDS security lending position)
    ————–
    18.8 billion
    —————
    (5.9) billion (collateral already in GS account)
    —————
    12.9 billion
    =========

    So there you go. Details you won’t see in the media.

    Also, in my opinion the treasury and Fed had no choice other than to pay GS the 12.9 billion. AIG owed it to them. The 2.5 billion was backstopped by other CDS, and GS would have selected them very carefully as it was to make up a known AIG deficit. Zero bargaining power for a haircut. Goldman already had the 5.9 billion. The Fed wanted Maiden Lane locked out of the real world – for good reasons. The 4.8 billion was GS’s stuff.

    Texas has been hot as H, and central Texas is having a severe drought. I’m in the Dakotas today. It was in the 60s this morning and damp. This climate change is killing me.

  • Mark // August 11, 2009 at 7:57 am

    “It is premature to assert that CNOPKSH sufficed.”

    But we have ammonia not just the elements that go into ammonia.

    We have water, not just the elements that go into water.

    We have other organic chemicals that, when zapped by electricity or UV (in an emission nebula, you have a hot white star in the middle: guess what comes out of a hot white star…), they form other complex chemicals that are building blocks for life.

    You’re assuming that what is out there is far less complex than it is.

    The interstellar medium is far further along the road to making life than you know.

  • Barton Paul Levenson // August 11, 2009 at 10:53 am

    bjchip: The short answer is that warming in upper layers also matters, and affects all the lower layers. A detailed explanation is here:

    http://BartonPaulLevenson.com/Saturation.html

  • bjchip // August 11, 2009 at 2:12 pm

    Thanks people. I do not know why I couldn’t find that on Realclimate. Strangely, nobody has challenged my answer anyway – So now I have to correct myself.

    I’ll bet they argue about THIS while my SWAG baffled them and it shut them down completely:-) Even though it was just a boundary condition.

    Truth must be served.

    Thanks again.

    BJ

  • Hank Roberts // August 11, 2009 at 2:32 pm

    > do not know why I couldn’t find that

    How did you look?

    Did you try this?
    http://www.google.com/search?q=realclimate+co2+saturated

  • Hank Roberts // August 11, 2009 at 2:47 pm

    In related news:

    http://economistsview.typepad.com/economistsview/2009/08/astroturf-trolls-for-the-blogosphere.html

    http://mandatemedia.typepad.com/photos/uncategorized/2007/07/16/blogattack.jpg

  • bjchip // August 11, 2009 at 2:48 pm

    I used the Realclimate index. Usually that serves me well.

    I didn’t google that specific combination I included the word “spectral” and I didn’t specify Realclimate. A few different tweaks but just one of my rare search failures. All my hits were denialist repetitions of the same stuff, to the extent that I finally decided to just ask.

    Thanks

    BJ

  • chriscolose // August 11, 2009 at 3:33 pm

    bjchip, Aslak has pointed out that we’re nowhere near saturated today. But, even if the atmosphere was completely saturated where CO2 absorbs, adding CO2 would still act to warm the planet since the vertical temperature profile is such that adding GHG’s will still make the planet radiate at a higher altitudes (lower pressure) and colder temperatures until a new equilibrium is reached. This serves to keep the effective temperature essentially unchanged while one must extrapolate further down the adiabat to get to the surface.

  • Hank Roberts // August 11, 2009 at 8:29 pm

    Hey, here’s a side thought:

    “DHA can be extracted from some marine microalgae and fatty fish. Because of the concern about the environmental pollution, more people now than ever prefer DHA from microalgae.”

    So that big petroleum company that’s trying to grow fuel from algae could also be growing — pharmaceuticals.

    It’s a diesel fuel _and_ a coronary care drug!

  • David B. Benson // August 11, 2009 at 10:38 pm

    Mark // August 11, 2009 at 7:57 am — This sums up abiogenesis conjectures:
    http://en.wikipedia.org/wiki/Abiogenesis
    Some are fairly exotic, including arsenic replacing either P or K (I don’t remeber which).

    None, however, as of yet consider the full range of geochemistry/geophysics required to have (sustained) abiogenesis. For example, the collision with the proto-moon caused Terra to be enriched in core and deficient in mantle in comparison to Venus. That may have very important in keeping the ocean & surface “climate” moderate enough until blue-green algae evolved to begin altering the atmosphere. That was about 1.6 billion years after the formation of Terra as a planet.

    Trying to bring this to a close, please go learn just how complex are even the simplest unicellular life forms, how specialized the conditions in which they live. Simple organic molecules floating around in space are a long way from a functioning cell.

  • Hank Roberts // August 12, 2009 at 1:47 am

    http://www.sciencenews.org/view/generic/id/46172/title/Titan_may_host_prebiotic_brew

  • Timothy Chase // August 12, 2009 at 4:09 am

    Mark wrote:

    You’re assuming that what is out there is far less complex than it is.

    The interstellar medium is far further along the road to making life than you know.

    I wouldn’t entirely discount the possibility that the materials formed right here on earth. Here are a few papers dealing with that possibility which may be of interest:

    Laura Schaefera and Bruce Fegley, Jr. (2007) Outgassing of ordinary chondritic material and some of its implications for the chemistry of asteroids, planets, and satellites, Icarus, Volume 186, Issue 2, February 2007, Pages 462-483
    http://arxiv.org/ftp/astro-ph/papers/0606/0606671.pdf

    Jeffrey L. Bada et al. (17 Oct 2008) The Miller Volcanic Spark Discharge Experiment, Science. Vol. 322. no. 5900, p. 404.
    http://astrobiology.gsfc.nasa.gov/analytical/PDF/Johnsonetal2008.pdf

    James P. Ferris (2005) Mineral Catalysis and Prebiotic Synthesis: Montmorillonite-Catalyzed Formation of RNA, Elements, Vol. 1, pp. 145-149
    http://www.origins.rpi.edu/pdf/elemv1n3_145_150.pdf

    Once you have that things start to get interesting:

    Tracey A. Lincoln, et al. (2009) Self-Sustained Replication of an RNA Enzyme, Science 323, pp 1229-1231
    http://www.sbs.utexas.edu/395J/395J_2009/Readings/Mol%20190/Self%20Sustained%20Rep%20of%20RNA%20enzyme.pdf

    Koonin et al, The ancient Virus World and evolution of cells
    Biology Direct 2006, 1:29doi:10.1186/1745-6150-1-29
    http://www.biology-direct.com/content/1/1/29

    Ferry JG, House CH (2006) The stepwise evolution of early life driven by energy conservation, Mol Biol Evol. Jun;23(6):1286-92
    http://mbe.oxfordjournals.org/cgi/content/full/23/6/1286

  • Mark // August 12, 2009 at 7:57 am

    “None, however, as of yet consider the full range of geochemistry/geophysics required to have (sustained) abiogenesis. ”

    Abiogenesis isn’t a sustained process.

    The biggest problems for interstellar life is

    1) some constancy in location. Planet(oid) or whatever. Something to leverage as a workspace for life
    2) energy. enough to kickstart life is enough to kill it off again, so you need *occasional* kicks, not continuing ones

    But that only really means that the constituents for life are abundant. Locations for life to continue once it starts requires something else.

    Then again, we’re already talking about planets which have the required factors in abundance.

    We aren’t going to solve this issue or even convince each other here, so I’ll go right back to the original reason I stuck my oar in:

    The only reason why you have “proven” (in quotes because it is proven only in your estimation) life is unlikely is the FACT of Venus and Mars not having life.

    And that IS a fact.

    But you are loading far too much on that evidence.

    It is only two planets in one solar system. Out of billions.

    It is only in the last few decades we have known for either. Out of billions of years.

    You are extrapolating far FAR along the graph from those two datapoints.

  • Mark // August 12, 2009 at 2:32 pm

    “I wouldn’t entirely discount the possibility that the materials formed right here on earth.”

    Neither would I Tim.

    But there’s a lot of “not earth” out there and most of the other planets in the universe are in that area.

    That Mars and Venus do not AT THIS TIME have life abundant upon them doesn’t mean that the chances of life existing out there must necessarily be minuscule.

  • Ian Forrester // August 12, 2009 at 2:39 pm

    Tammy, have you had a look at this latest “paper” by McIntyre and McKitrick entitled “An updated comparison of model ensemble and observed temperature trends in the tropical troposphere” which is going around the denierosphere claiming to debunk the Santer et al. (2008) paper on the tropical troposphere hotspot?

    http://arxiv.org/ftp/arxiv/papers/0905/0905.0445.pdf

  • Andrew Dodds // August 12, 2009 at 3:31 pm

    Mark, Tim -

    There is another critical data point; as far as we can tell, life appeared essentially instantly (to within <100ma) on the planet; as soon as it was possible to have evidence, there appears to be evidence.

    This supports the view that abiogenesis is a rapid process, which happens under a fairly generic set of conditions (I strong suspect hydrothermal vents, which at least have the energy gradients and chemical concentrations required). If we had solid evidence of a sterile planet for, say, the first 2 billion years followed by the sudden appearance of the first life, that would at least suggest abiogenesis to be a freak event.

    It also follows that the time to transition from minerals to self-sustaining life form cannot be much more than 10-100k years; no potential environment is likely to last any longer.

    So I subscribe to the view that basic microbial life is probably very common in the universe; any planet with liquid water and a sun capable of splitting water to hydrogen and oxygen should have it.. However, more complex organisms are far harder to come up with. Even on earth, out of roughly 5.5Ga that the planet will stay in the habitable zone, it took roughly 4Ga for anything to climb out of the water and a further 0.5Ga before it worked out what water was. Many, many biospheres, even extremely stable ones like ours, will have gone Venus, being burnt up by their star gradually heating up, been sterilized by a particularly large asteroid, or whatever, long before life you could see, let alone talk to turned up.

  • Deech56 // August 12, 2009 at 7:35 pm

    Nature has an interesting News article about the number of Climate Audit-generated FOIA requests being received by the CRU of the University of East Anglia. The money quote from the article: “McIntyre insists that he is not interested in challenging the science of climate change or in nit-picking, but is simply asking that the data be made available. ” Yes, they don’t engage in “nit picking.”

    Actually, there are several good articles in that issue.

  • Timothy Chase // August 12, 2009 at 9:27 pm

    Deech56 wrote:

    Nature has an interesting News article about the number of Climate Audit-generated FOIA requests being received by the CRU of the University of East Anglia….

    Actually, there are several good articles in that issue.

    Wow. I didn’t realize they had so much open access material on HIV.

    I take a real interest in retroviruses and other retroelements. Past couple weeks or so I and a friend of mine have arguing (tacitly) about whether LINEs are highly degenerate endogenous retroviruses (his position) or whether retroviruses are highly chimeric LINEs with LINEs essentially being group II introns in a eukaryotic nuclear context. The latter is my position — and that of mainstream literature, I believe. Unlike spliceosomal introns, group II introns (at least in bacteria and archaea) are generally mobile self-splicing, reverse-transcribing retroelements.

    From what I understand, phylogenetic analysis of the associated reverse transcriptases necessarily puts LINEs and group II closer to one-another than either is to retroviruses, and similarly, both closer to the Mauriceville retroplasmid — which is generally acknowledged as having the more promiscuous and primitive reverse transcriptase — as it requires no coding DNA template. Given this LINEs would appear to have preceded retroviruses. Likewise, retroviruses clearly do not extend to bacteria but group II introns are fairly widespread at that level — although at first they seemed limited to cyanobacteria. So — according to the mainstream view — for LINEs to give rise to retroviruses two things would have to happen.

    First, the LINE would have to acquire a DNA transposon (as its LTR) and its integrase. And interestingly enough, we have discovered a DNA transposon in social amoeba which has an integrase that appears closely related to that of LTRs. At that point you have what is essentially an LTR retrotransposon. Second, the LTR retrotransposon would have to acquire an envelope gene — similar to the g160 that is the precursor to g120 binding protein and the g41 transmembrane fusion protein. And interestingly enough g160 appears to be closely related to similar precursor membrane proteins used by the paramyxovirus, influenza virus, ebola and others. And each has a protein that closely corresponds to the g41 protein, having two conformations — where the transition between the two essentially harpoons the cells that they infect.

    All of this may seem fairly esoteric. However, one of the payoffs in all this is that if one discounts the spliceosomal introns that appear to have descended from early group II introns, 49% of our genome still consists of retroelements. Of this approximately 8% consists of endogenous retroviruses. Three endogenous retroviruses appear to play complementary roles in creating a barrier to the mother’s immune system — that would otherwise treat the developing embryo as non-self and reject it like a transplanted organ. Likewise, SINEs (which are non-autonomous retroelements produced by template switching during the retrotransposition of LINEs) appear to be responsible for the generation of alternate CIS-regulatory elements, and both LINEs and SINEs appear to be responsible for the generation of tandem repeats.

    The latter give rise to a plasticity and consequent evolvability of the genome inasmuch as they facilitate recombination and after ten or so repetitions of a given motif tend to reversibly hypermutate — acting essentially as tuning dials on the CIS regulatory elements and protein coding regions of our genes. Then where needed point mutations can break tandem repeats up into cryptic (amino acid) repeats so that they still code for the same proteins but are no longer subject to hypermutation.

  • TrueSceptic // August 13, 2009 at 5:57 pm

    Just to mention that Michael Mann is lead author of a new paper on hurricane frequency.

    The personal attacks on Mann and lies about his work at Watts are a disgrace. Where are the “moderators”?

  • David B. Benson // August 14, 2009 at 12:12 am

    Mark // August 12, 2009 at 7:57 am — Sorry, I wasn’t clear. Abiogenesis might occur, but not soon enough, or evolve fast enough, to begin changing the atmosphere and so avoid the Vensus effect, ending life on that planet.

    I certainly have not “proven” anything; I simple state a highly tenable position. From my limited understanding of planetary formation (good article several months ago in Scientific American), the probability of a nearly double planet (Erath Moon) which the right chemical compostion to avoid Vensus’s geologic history strikes me as very rare. Recent discoveries of extrasolar planetary systems also suggest this rarety.

    On top of that, somehow the earliest organisms have to develop cell walls and an internal metabolism; finally they have to evolve photosynthesis soon enough (requiring a partially transparent atmosphere). I find all of this to be a very low probability sequence of events, vanishingly smaller than even Ward & Brownlee.

    Still, I found “Rare Earth” quite, quite good.

  • Timothy Chase // August 14, 2009 at 9:22 pm

    David B. Benson wrote:

    Sorry, I wasn’t clear. Abiogenesis might occur, but not soon enough, or evolve fast enough, to begin changing the atmosphere and so avoid the Vensus effect, ending life on that planet.

    I am still not sure that you are being all that clear, David. Which planet? Venus? That life would begin and evolve quickly enough in its history to avoid the “Venus” effect? Well, if by “Venus” effect you mean the runaway greenhouse effect it would appear you are right.

    David B. Benson wrote:

    I certainly have not “proven” anything; I simple state a highly tenable position.

    Perhaps. But what is it exactly? And have you actually demonstrated it to be tenable?
    *
    David B. Benson wrote:

    From my limited understanding of planetary formation (good article several months ago in Scientific American), the probability of a nearly double planet (Erath Moon) which the right chemical compostion to avoid Vensus’s geologic history strikes me as very rare.

    Why would the evolution of a habitable planet have to take precisely the same path that the earth took? Perhaps with material left over from a different — larger or smaller — second generation star it would have a composition that would be appropriate for a smaller star at a closer distance subject to larger tidal forces independently of any moon. And what would happen if the planet itself were further away from its star but with a venus-size greenhouse effect? A lot of different variables to play with, aren’t there.
    *
    David B. Benson wrote:

    Recent discoveries of extrasolar planetary systems also suggest this rarety.

    Which recent discoveries? I thought that we hadn’t quite gotten to the level of being able to detect earth-size planets. Three times or five times earth mass, but not actually earth mass or smaller. Do you know something different?
    *
    David B. Benson wrote:

    On top of that, somehow the earliest organisms have to develop cell walls and an internal metabolism; …

    Well yes, if they are to be cellular life — which is generally what we are concerned with. But how long does this take?
    *
    David B. Benson wrote:

    … finally they have to evolve photosynthesis soon enough (requiring a partially transparent atmosphere).

    Well, we have evidence that photosynthesis began 3700 million years ago, at least according to this:

    Dramatic progress has been made over the last decade understanding the fundamental reaction of photosynthesis that evolved in cyanobacteria 3.7 billion years ago, which for the first time used water molecules as a source of electrons to transport energy derived from sunlight, while converting carbon dioxide into oxygen.

    Bacteria Power: Future For Clean Energy Lies In ‘Big Bang’ Of Evolution
    ScienceDaily (Aug. 25, 2008)
    http://www.sciencedaily.com/releases/2008/08/080825092353.htm

    … and at least according to one “expert” (who I would presume knows more than either of us, but not necessarily a great deal), Venus may have had oceans as recently as 1,000 to 3,000 million years ago:

    Liquid water oceans may have been present on Venus as recently as 1 billion to 3 billion years ago, Svedhem said.

    From: Reuters
    Published November 28, 2007 03:40 PM
    Lightning detected on “evil twin” Venus
    By Will Dunham
    http://www.enn.com/top_stories/article/26073

    *
    David B. Benson wrote:

    I find all of this to be a very low probability sequence of events, vanishingly smaller than even Ward & Brownlee.

    It is clear that you have opinions, David. But do you have any sources for your opinions? I believe that with every point of mine that I mentioned regarding retroelements and viruses a couple or so posts above I could cite one or more technical papers that has passed peer review and quote from it the passage that I believe supports that point.

    Can you do anything similar?

    If not do you actually have reasons for your opinions? Can you actually provide some sort of justification for those opinions? And perhaps more to the point, are your opinions actually your opinions — or merely positions that you think playable — in some sort of game of “recreational arguing”?

    I don’t necessarily see anything wrong with “recreational arguing.” Sometimes being a devil’s advocate may serve a purpose — honing the skills of all those involved.

    But it helps if people know that this is actually what you are doing — at least from their perspective. Otherwise, as with a troll — you may simply “play difficult” as they try to reason you out of what they take to be your sincere beliefs — and that is in all likelihood in no one’s interest — including your own.

    Besides, maybe they just wouldn’t be interested in that sort of game. It isn’t exactly fair if you are the only one who knows the rules that are in play in the game that you are playing.

  • David B. Benson // August 15, 2009 at 12:22 am

    Timothy Chase // August 14, 2009 at 9:22 pm — Thanks for the reply. I’m trying to put together the little I know about planetary formation, existing unicelluar lifeforms (Carl Zimmer has a useful recent review of the evolution), conjectures about abiogenysis (including Ward & Brownlee) to hold an argueable position regarding the rarity of life persisting on any planet even slightly different than Terra. Not just the rarity of abiogenesis; the geological evolution might destroy all life on some planet X (say, having a history similar to that of Venus).

    I doubt the evidence for cyanobacteria 3.7 billion years ago is very credible. AFAIK the eariest formation which might, just might, evidence cellular structure due to life forms is dated at 3.45 billion years ago. In that case there is no reason to expect cyanobacteria. The oldest rock formations thought to be due to ancient stromatolites is dated at 2.8 billion years ago. Of course, rock geologists keep finding older credible specimens and I could well be behind the times.

    I certainly hawe not the least idea how long it takes, under the right conditions, for some primitive life form to evolve; the Wikipedia article offers the conjectures of others. I’m offering the suggestion that the step from the first to cellular organisms is a fairly big step. In any case, viruses are clearly parasites which evolved later, IMHO.

    The exoplanets are all larger than Terra, but that might matter less than one might suspect; what does matter is the distance and distribution from the parent star as well as the chemical patrimony. Such observed distributions have caused a revolutiion in the understanding of planetary formation and IMO make a planet capable of supporting life much less likely. As for changing from a G2 star for starters, read Ward & Browlee; it ain’t gonna work.

    What I have learned from these exchanges is that the precise geologic history, which is modified by the presence of life, if any, makes a difference in the persistence of life. This is somehow related to the Lovelock/Margulis Gaia hypothesis, which I don’t actually understand. Anyway, I pointed out earlier that the chemical patrimony of Terra was modified by the impact with the proto-moon to be different in ways which may be very important for abiogenesis or persistence of life forms; very different that the average of the materials out of which both the proto-earth and Venus were formed.

    Like everybody else, I just conjecture about abiogenesis and life persistence. My sense of the probabilites happens to be lower than Ward & Brownlee regarding the formation of unicellular life but higher regarding the formation of multicellular life once the unicellular forms have become well established. In the long term, when something more definite can be said it may be well be that everyone has taken the wrong tack.

    Yes, by Venus effect I meant runaway greenhouse.

    My opinions keep evolving with increased data and some exchanges such as these. Consider it part of my 50+ year amateur interest in geology, which of course has to consider planetary, climate and biological evolution to some extent.

  • Hank Roberts // August 15, 2009 at 12:38 am

    “It is easy to lie with statistics. It is hard to
    tell the truth without statistics”

    Andrejs Dunkels

    http://www.phy.duke.edu/~hsg/quotes.txt

  • Barton Paul Levenson // August 15, 2009 at 11:35 am

    David,

    If it helps, here’s an essay I did on a related question about 12 years ago:

    http://BartonPaulLevenson.com/N.html

    I also highly recommend Stephen H. Dole’s “Habitable Planets for Man” (1964). Despite the old information, the approach used is very informative.

    Ward and Brownlee have a lot of interesting things to say, but the idea that only G2V stars can support habitable planets is not shared by any astronomer I know, and I know quite a few of them, including George Gatewood and Francis Graham. My own estimate is that anything from about F7V on down can probably have a habitable planet. I used to excluse red dwarfs, but after the work of Haberle and Joshi (which I wasn’t aware of when I wrote the article I cited above), I no longer put down a lower limit. And F7V and later is more than 75% of the main sequence stars in the galaxy.

  • Barton Paul Levenson // August 15, 2009 at 11:36 am

    I meant “exclude” above, of course. “Excluse” isn’t even a word.

  • Timothy Chase // August 15, 2009 at 3:11 pm

    Abiogenesis, Life and Viruses, Part I of II

    David B. Benson wrote:

    Thanks for the reply. I’m trying to put together the little I know about planetary formation, existing unicelluar lifeforms (Carl Zimmer has a useful recent review of the evolution), conjectures about abiogenysis (including Ward & Brownlee) to hold an argueable position regarding the rarity of life persisting on any planet even slightly different than Terra. Not just the rarity of abiogenesis; the geological evolution might destroy all life on some planet X (say, having a history similar to that of Venus).

    I do think that I misunderstood you, particularly when you stated:

    Trying to bring this to a close, please go learn just how complex are even the simplest unicellular life forms, how specialized the conditions in which they live. Simple organic molecules floating around in space are a long way from a functioning cell.

    Coming from the “pro-evolution” online community that supports the science of evolutionary biology and its being taught in schools, the first sentence at least in that paragraph sounded a bit like the creationist saw that “life is just too complicated to have arisen by chance.” But of course chance is only part of the equation, as there are also the laws of physics and natural selection — however far down the latter may apply.

    I would however point out that it doesn’t really make much sense to judge the requirements of early unicellular life based upon modern unicellular life. Modern bacteria are complex — but they have had billions of years in which to become that way. And a large part of that complexity is the result of their having to live in an environment where competitors, predators and prey have similarly become complex. What may have worked in the past simply can’t work today — because everyone has moved ahead. This is part of the “Red Queen Hypothesis.” “Behold the complexity of the eye” — and how it probably began as simply a light-sensative patch. Then again, we know of amoeba with lens eyes.

    Please see for example:

    David Francis (1967) On The Eyespot of the Dinoflagellate, Nematodinium, j . Exp. BM. (1967), 47,495-501
    http://jeb.biologists.org/cgi/reprint/47/3/495.pdf

    … and:

    J. D. Dodge and R. M. Crawford (1969), Observations on the Fine Structure of the Eyespot and Associated Organelles in the Dinoflagellate Glenodinium Foliaceum, J. Cell Sci. 5, 479-493
    http://jcs.biologists.org/cgi/reprint/5/2/479.pdf

    Returning to bacteria, one finds for example that modern bacteria have cytoskeletons and some have organelles of a sort that appear similar to viral capsids.

    Please see for example:

    For Yeates, the resemblance of micro-compartments to viruses is not coincidental, even if the exact evolutionary history remains uncertain. “The question remains open as to whether viruses and bacterial micro-compartments represent a case of convergent or divergent evolution,” he said. “At this point, there isn’t really any substantial evidence to support either case [...] If it turns out to be a case of convergent evolution, this will reinforce the idea that highly ordered protein assemblies occur relatively often by chance during evolution, and so have arisen multiple times independently, and in different functional contexts. If it turns out to be a case of divergent evolution-meaning bacterial micro-compartments share a common ancestry with some virus-the situation will be reminiscent of the endosymbiotic hypothesis, which holds that organelles in eukaryotes derived from prokaryotic organisms.”

    Philip Hunter ( 2008 March) Not so simple after all. A renaissance of research into prokaryotic evolution and cell structure, EMBO Rep.; 9(3): 224-226.
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=226738

    *
    David B. Benson wrote:

    I doubt the evidence for cyanobacteria 3.7 billion years ago is very credible. AFAIK the eariest formation which might, just might, evidence cellular structure due to life forms is dated at 3.45 billion years ago. In that case there is no reason to expect cyanobacteria. The oldest rock formations thought to be due to ancient stromatolites is dated at 2.8 billion years ago. Of course, rock geologists keep finding older credible specimens and I could well be behind the times.

    I would agree with this. My only concern regarding photosynthesis is that the period over which it may have arisen overlaps with when Venus may have had an ocean — where it may have had one as recently as a billion years ago. And if you were claiming that photosynthesis couldn’t have evolved early enough to have stopped the runaway greenhouse effect on Venus, as I have stated, it would appear that you are right — but only because Venus was in fact subject to a runaway greenhouse effect.
    *
    David B. Benson wrote:

    I certainly hawe not the least idea how long it takes, under the right conditions, for some primitive life form to evolve; the Wikipedia article offers the conjectures of others. I’m offering the suggestion that the step from the first to cellular organisms is a fairly big step.

    From the first form of life to cellular organisms?

  • Timothy Chase // August 15, 2009 at 3:13 pm

    Abiogenesis, Life and Viruses, Part II of II

    David B. Benson wrote:

    In any case, viruses are clearly parasites which evolved later, IMHO.

    I am afraid I would have to disagree here.

    At our level it is easy — for the most part — to distinguish between the host and its parasite, particularly when the parasite is small — like a virus — relative to its host. However, even at our level things become a little blurry. If you go back, of course, the chloroplasts are themselves descended from ancient cyanobacteria and the mitochondria are descended from a bacteria that was closely related to the Rickettsia bacteria, and their relationship with their host was first entered through either predation or parasitism transforming all extant eukaryotes. But much more recently, endogenous retroviruses — which begin as laterally transmitted exogenous viruses but insert themselves in the germline genome — appear to exert a strong influence upon the development of their host.

    Endogenous retroviruses are strongly expressed in the placenta of all the placental mammals we have examined. We have also seen that they are highly expressed in many tissues and in the placenta during early pregnancy, suggesting that they play important roles in regulating embryonic development.

    Please see:

    Frank P. Ryan (2004) Human endogenous retroviruses in health and disease: a symbiotic perspective (Open Access)
    J R Soc Med 2004;97:560-565
    http://jrsm.rsmjournals.com/cgi/reprint/97/12/560

    Likewise, they have been implicated in the ability of the placenta to implant itself in the uteran wall without being immediately rejected.

    Please see:

    Syncytin-A knockout mice demonstrate the critical role in placentation of a fusogenic, endogenous retrovirus-derived, envelope gene (abstract only)
    Anne Dupressoir, Cécile Vernochet, Olivia Bawa, Francis Harper, Gérard Pierron, Paule Opolon and Thierry Heidmann (edited by
    PNAS July 21, 2009 vol. 106 no. 29 12127-1213
    http://www.pnas.org/content/106/29/12127

    However, at the bacterial level lateral gene transfer is rampant — so much that it is often difficult to construct phylogenetic trees — and generally plays a pivotal role in bacteria’s ability to adapt to its environment — and it generally plays a central role in the ability of bacteria to adapt to its environment.

    Please see:

    Howard Ochman et al. (2005) Examining bacterial species under the specter of gene transfer and exchange, Proc Natl Acad Sci U S A. 2005 May 3; 102(Suppl 1): 6595–6599.
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1131874

    Lerat E, Daubin V, Ochman H, Moran NA (2005) Evolutionary Origins of Genomic Repertoires in Bacteria. PLoS Biol 3(5): e130.
    http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030130

    Turlough M. Finan, (June 2002) Evolving Insights: Symbiosis Islands and Horizontal Gene Transfer, J Bacteriol. 184(11): 2855-2856
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=135049

    However, the further back in time and the more primitive the cell the greater the role one can expect between viruses and their hosts and the blurrier (it would appear) the boundary. Simply in terms of genome size they would become much more comparable. And if mineral structures played the role of cell walls early in the evolution of cells and genomes were more loosely bound to those cells and with the most primitive cells being largely if not wholy dependent upon geological processes rather than a well-developed internal metabolic cycle then it would seem that the distinction between parasite and host would all but evaporate — as is suggested in two of the earlier papers I referenced.

    Please see:

    Koonin et al (2006) The ancient Virus World and evolution of cells, Biology Direct, 1:29doi:10.1186/1745-6150-1-29
    http://www.biology-direct.com/content/1/1/29

    Ferry JG, House CH (2006) The stepwise evolution of early life driven by energy conservation, Mol Biol Evol. Jun;23(6):1286-92
    http://mbe.oxfordjournals.org/cgi/content/full/23/6/1286

    In any case, my participation in any discussion over matters such as this will have to be quite limited over the next week or so, but I would be willing to discuss further. But if you would be interested in continuing this discussion here or off-blog…

    timothychase (at) gmail (dot) com

  • Hank Roberts // August 15, 2009 at 4:35 pm

    Guys, this is like that old argument about how many teeth a horse has, from tradition and first principles.

    We can instead go look.

    The likely presence of ammonia on Titan’s icy surface, combined with the abundance of methane and nitrogen in the moon’s thick atmosphere, together suggest …
    http://www.sciencenews.org/view/generic/id/46172/title/Titan_may_host_prebiotic_brew

  • Timothy Chase // August 15, 2009 at 6:03 pm

    Hank Roberts wrote:

    Guys, this is like that old argument about how many teeth a horse has, from tradition and first principles.

    Hank, we have been studying ribozymes since the 1980s — which get you out of the chicken-and-the-egg conundrum of which came first, DNA or protein enzymes? We know that if you have the appropriate organic bath a “virus” as small as 80 nt can replicate without the benefit of cellular machinery. We know that given ribonucleotides and montmorillonite, RNA will self-assemble into chains as long as 50 nt.

    Likewise, the theory proposed by House and Ferry grew out of the study of the metabolic pathways of methanogens in general and methanosarcina acetivorans in particular. Now unless you have a frame-by-frame film of cells spontaneously forming on Titan, I don’t see how your “approach” is going to be any more empirical than what scientists have been doing right here in our own backyard for the past several decades — and which has sped up considerably within the past decade — if I am not mistaken.

    Would Titan, Europa or Mars be worth studying? Certainly. And I wouldn’t be all that surprised if we were to find primitive cells on at least one of these bodies. Heck, I hope that we do find something like that within my lifetime.

    But the earth is a little closer, making the evidence it has far more available — and it has been studied in a great deal more detail. And it sounds like what you have on Titan isn’t all that different from the missing Miller experiment…

    Jeffrey L. Bada et al. (17 Oct 2008) The Miller Volcanic Spark Discharge Experiment, Science. Vol. 322. no. 5900, p. 404.
    http://astrobiology.gsfc.nasa.gov/analytical/PDF/Johnsonetal2008.pdf

    … and yet that is only one piece in the puzzle.

  • Timothy Chase // August 15, 2009 at 6:11 pm

    PS

    I guess for me the big question isn’t, “How rare is life?” Personally I think bacterial life of some sort beyond earth isn’t that uncommon, but I can’t wait for it to be discovered. But for me the big question is, “How did life arise?”

  • David B. Benson // August 15, 2009 at 6:25 pm

    Timothy Chase // August 15, 2009 at 3:13 pm — Thanks, but we’ll just have to disagree about an early role for viruses it seems. Modern organisms are too complex and complexly interrelated to offer much guidance for abiogenesis.

    For early conditions on Terra, at the end of the
    http://en.wikipedia.org/wiki/Hadean
    about 3.8 billion years ago, there are the earliest
    http://en.wikipedia.org/wiki/Banded_iron_formation
    which suggests the presense of primitive
    http://en.wikipedia.org/wiki/Chemoautotroph
    organisms, as I don’t know of any other way to produce the iron oxides. If at all similar to modern ones, this implies the organization of cell membrane (wall) and internal metabolism by that time, about 600 million years after Terra’s formation.

    Various of the proposals for first life include a simplified metabolism without an organic cell membrane; that being provided inorganically by clay microstructure or some such. All highly speculative.

    What I think I have learned out of these exchanges is that it is a race against time to remove methane and carbon dioxide at least as fast as those outgas; failure to do so seems to lead to runaway greenhouse. On Terra, it was fast enough to lead to the
    http://en.wikipedia.org/wiki/Oxygen_catastrophe
    providing one of the preconditions for multicellular life. That was about 2.4 billion years ago and for whatever reason did not occur on Venus.

    Why not? I’ve offered the suggestion that it was the different chemical patrimony that made the difference. Of course, early life on Venus, if any, may never have evolved suitable organisms to remove enough CO2 fast enough. Evolution not only requires suitable conditions, but also perhaps enough time. Under that assumption Terra was lucky enough to hit the right combination but Venus was not. Dunno.

    I certainly do not support “irreducible complxity”, just a high improbabilty. In an earlier post I argued that in a large enough cosmos such a low probability event will occur; that suffices.

    Barton Paul Levenson // August 15, 2009 at 11:35 am — The factors are the chemical composition of the leftover bits (making up Venus and Terra-Luna here) and also stellar lifetime and stability.

    I assume there is some variation in chemical composition, some being more suitable than others. Even if lots of main sequence stars are suitable that doesn’t not much affect the argument that producing a Terra-Luna twin planet is a requirement (if it is) and that must be most rare.

  • Timothy Chase // August 15, 2009 at 7:14 pm

    David B. Benson wrote:

    Thanks, but we’ll just have to disagree about an early role for viruses it seems. Modern organisms are too complex and complexly interrelated to offer much guidance for abiogenesis.

    Personally I wouldn’t be trying to answer the question of how unlikely it is for life to have arose without trying to answer how it arose — that is, assuming we are speaking of bacterial life. However, you are right, sometimes people just have to agree to disagree. Besides, this isn’t really the venue.

    At the same time, we both agree that no matter how rare life is, the likelihood of it arising through natural processes is greater than zero — and given a large enough laboratory with a wide enough variation in initial conditions it can be expected to arise. And that is something.

  • David B. Benson // August 15, 2009 at 8:13 pm

    Timothy Chase // August 15, 2009 at 7:14 pm — I believe we are in essential agreement.

    Of closely related interest is:
    The rise of atmospheric oxygen
    Lee R. Kump
    Abstract
    Clues from ancient rocks are helping to produce a coherent picture of how Earth’s atmosphere changed from one that was almost devoid of oxygen to one that is one-fifth oxygen.
    http://www.nature.com/nature/journal/v451/n7176/full/nature06587.html
    If that is behind a paywall for you, perhaps the important figure is not:
    http://www.nature.com/nature/journal/v451/n7176/fig_tab/nature06587_F2.html

    This paper suggests just how little is actually understood about deep time,
    http://en.wikipedia.org/wiki/Archean
    and before. So yes, conjectures about abiogenesis and early life survival rate remain simply speculation.

  • Timothy Chase // August 16, 2009 at 2:25 am

    David B. Benson wrote:

    Of closely related interest is:
    The rise of atmospheric oxygen
    Lee R. Kump

    The 2008? Found it.

    David B. Benson wrote:

    This paper suggests just how little is actually understood about deep time,
    http://en.wikipedia.org/wiki/Archean
    and before. So yes, conjectures about abiogenesis and early life survival rate remain simply speculation.

    There are a lot of questions that remain unanswered. For example, where did life originate? Was it along the shores of an ancient ocean, in small lakes or ponds conentrating chemistry near the surface or the beaches or as the result of evaporation. There have been arguments that it may have been dependent upon cycles of freezing and melting — as this would speed up and concentrate some certain chemical while preserving their products.

    One of the favorites nowadays involves geothermal black smokers along the ocean floor. Chemical and thermal gradients would promote a process of self-organization. Even today such black smokers display a rich diversity of life. The cycling of water through such hydrothermal plumbing could promote chemical reactions that would presumably produce the right products without destroying them — since the products would be cycled back out into cooler waters. And this would be largely independent of surface conditions.

    However, one thing we are fairly confident about is the fact that at one point life was based not upon DNA but RNA. Even today life as we know it is largely dependent upon RNA. The spliceosome (the major one at least, and probably both) is largely reliant upon ribozymes for splicing introns, such that we expect it could perform its action independently of proteins — although not necessarily as well. The telomeres at the end of our chromosomes encode a reverse transcriptase, appears related to pFOXC retroplasmids. The reverse transcriptases found among in bacterial group II introns appears closely related to that of LINEs, more distantly related to those of endogenous retroviruses and so on.

    Any one piece could be dismissed, but their weight is cummulative. And the fact that DNA can only encode but cannot form transcripts or translate those transcripts to proteins without proteins, but proteins cannot be coded for without some molecule that stores the information that encodes them, such that DNA and proteins are interdepent and must work in concert with one another, whereas RNA can perform the functions of both, acting as a genetic code and as an enzyme — provides even more weight. And the fact that we have discovered a ribozyme that is capable of self-sustaining self-replication such that it could continue indefinitely is further evidence. Moreover, unlike many of the proteins that are coded for, even among RNA viruses the evolution of reverse transciptase is strongly conserved — such that we can build a strong case for the phylogenetic tree that is built on the basis of their respective codes.

    Did some other replicator precede the RNA world? Many think so, but I haven’t seen any strong candidate for it. However, we know that the RNA World didn’t exist for very long. The last common ancestor of archaea, eukarya and bacteria was already using DNA:

    This model clarifies how DnaA engages and unwinds bacterial origins and suggests that additional, regulatory AAA+ proteins engage DnaA at filament ends. Eukaryotic and archaeal initiators also have the structural elements that promote open-helix formation, indicating that a spiral, open-ring AAA+ assembly forms the core element of initiators in all domains of life.

    Jan P Erzberger, Melissa L Mott & James M Berger (2006) Structural basis for ATP-dependent DnaA assembly and replication-origin remodeling, Nature Structural & Molecular Biology – 13, 676 – 683 (2006)

    Incidentally, I found that the two smallest strains of the Qβ phage were identified by Manfred Eigen in 1996 were 48 and 52 nucleotides long.

    Please see:

    Oehlenschläger F Eigen M. 30 years later–a new approach to Sol Spiegelman’s and Leslie Orgel’s in vitro evolutionary studies. Dedicated to Leslie Orgel on the occasion of his 70th birthday. Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life. 1997 Dec;27(5-6):437-57.

    This puts it within the range of 40-50 nucleotides that spontaneously formed in James P. Ferris’ experiments.

    Please see:

    James P Ferris (2006 October 29) Montmorillonite-catalysed formation of RNA oligomers: the possible role of catalysis in the origins of life, Philos Trans R Soc Lond B Biol Sci.; 361(1474): 1777–1786.
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1664692

  • Mark // August 16, 2009 at 3:39 pm

    “Mark // August 12, 2009 at 7:57 am — Sorry, I wasn’t clear. Abiogenesis might occur, but not soon enough, or evolve fast enough, to begin changing the atmosphere and so avoid the Vensus effect, ending life on that planet.”

    Why would abiogenesis have been required to stop a runaway greenhouse effect?

    Less greenhouse gas in the first place would be amply sufficient.

  • Timothy Chase // August 16, 2009 at 5:12 pm

    Mark wrote:

    Why would abiogenesis have been required to stop a runaway greenhouse effect?

    Less greenhouse gas in the first place would be amply sufficient.

    Alternatively, why not keep the carbon dioxide but just move the planet a little further out from its star? Or make the star a little smaller? No runaway greenhouse effect. Then assuming the source of energy that drove the geological processes that gave rise to abiogenesis occurred along the ocean floor, e.g.,

    From the abstract: Building on the model of Russell and Hall for the emergence of life at a warm submarine hydrothermal vent, we suggest that, within a hydrothermally formed system of contiguous iron-sulfide (FeS) compartments, populations of virus-like RNA molecules, which eventually encoded one or a few proteins each, became the agents of both variation and selection. The initial darwinian selection was for molecular self-replication.

    On the origin of genomes and cells
    within inorganic compartments
    Eugene V. Koonin and William Martin
    Trends Genet. 2005 Dec;21(12):647-54. Epub 2005 Oct 11
    http://www.molevol.de/publications/135.pdf

    Then what is driving this process isn’t solar energy but geothermal energy. So if it takes longer for the surface to heat up, so be it.

    I think one thing may critics of abiogenesis theories don’t get is that many of these theories aren’t actually mutually exclusive. Instead they deal with different albeit related problems in explaining the origin of life — and they may be different pieces of the same puzzle. You can see that with the above article — written by Eugene Koonin — who also authored:

    Koonin et al (2006) The ancient Virus World and evolution of cells, Biology Direct, 1:29doi:10.1186/1745-6150-1-29
    http://www.biology-direct.com/content/1/1/29

    Iron sulfide is also mentioned here:

    Ferry JG, House CH (2006) The stepwise evolution of early life driven by energy conservation, Mol Biol Evol. Jun;23(6):1286-92
    http://mbe.oxfordjournals.org/cgi/content/full/23/6/1286

    Iron sulfide, acetate, methane and carbon dioxide are all part of the process involved in the simple geothermal-process/metabolism identified by House and Ferry. Many of the organic compounds that would have been required by early life are produced around both black and white geothermal chimneys found along the bottom of the ocean floor. Iron sulfide chimneys are found around both, driven by the same geothermal energy. And white chimneys last for thousands of years. It will form precisely the sort of inorganic chambers that might have played the role of inorganic compartments prior to the invention of lipid cell walls.

    Moreover, there are deposits of the montmorillonite around such geothermal vents, the very same material that Ferris used as an inorganic template for RNA-oligomers in the experiments where chains that were 40-50 nucleotides long were spontaneously produced and were of the same length as the shorter Spliegelman monsters that self-replicated in Manfred Eigen’s experiments. (Please see my earlier comment here, near the end.)

    We may not be able to say precisely when and where life began on earth or where else microbial life may have evolved. But we can come up with different scenarios and say that some are far more detailed and likely than others. And in time with the scenarios for the origin of life on earth we should be able to weigh the evidence that, as in the case of most science, is cumulative. And we should be able to say that of the scenarios that are available to us, one is far more likely and credible than the others.

  • David B. Benson // August 16, 2009 at 11:12 pm

    Mark // August 16, 2009 at 3:39 pm — Alas, no. The geochemical/geophysical processes would continue to outgas CO2 “forever”. Exposed ultramafic rock ewill eventually form carbonates, removing CO2, but he reaction rates are quite slow. Need biological organisms to add CO2 removing energy and processes.

    Starting with less CO2 is hardly credible; the primorial letfs over bits after stellar formation are always full of CO2 or progenitors.

  • David B. Benson // August 17, 2009 at 12:57 am

    Timothy Chase // August 16, 2009 at 2:25 am — Not clear that there was a single common ancestor. I’ve seen one paper offering the suggestion of multiple independent abiogenesis events.

    More important, in my view, is planetary embryology:
    http://www.nature.com/nature/journal/v451/n7176/full/nature06582.html
    with the figure describing the proto-Terra-proto-Luna impact results being
    http://www.nature.com/nature/journal/v451/n7176/fig_tab/nature06582_F2.html
    and so a mantle quite unlike that of Venus. Of additional interest are the comments regarding plate tectonics; it seems it need not have happened. (If not to deep sea smokers.)

  • Timothy Chase // August 17, 2009 at 1:55 am

    David B. Benson wrote:

    Sorry, I wasn’t clear. Abiogenesis might occur, but not soon enough, or evolve fast enough, to begin changing the atmosphere and so avoid the Vensus effect, ending life on that planet.

    Mark responded:

    Why would abiogenesis have been required to stop a runaway greenhouse effect?

    Less greenhouse gas in the first place would be amply sufficient.

    David B. Benson responded:

    Alas, no. The geochemical/geophysical processes would continue to outgas CO2 “forever”. Exposed ultramafic rock ewill eventually form carbonates, removing CO2, but he reaction rates are quite slow. Need biological organisms to add CO2 removing energy and processes.

    How good are single-celled creatures at removing carbon dioxide and creating mineral deposits? I mean, what matters in the long-run isn’t how carbon dioxide moves between the shallow pools of say the soil, the atmosphere or ocean — what is in the shallow pools equilibriates between the shallow pools anyways — but between the shallow pools and the geological carbon pool. So if we are talking about biological removal from the shallow pools putting carbon back into the geological carbon pool, I believe we are talking about shell-formation and…

    Global Warming, The Carbon Cycle, and Fish Poop.
    http://scienceblogs.com/authority/2009/01/global_warming_the_carbon_cycl.php

    But if there aren’t any multicellular creatures — which take a while I to arrive on the scene I believe — perhaps a little over three billion years — then we aren’t having much of either of that for quite some time. And according to your argument that puts all of us in a pile of deep… well, you know what I mean. Incidently, do you have any numbers and sources on any of the processes you are considering…?

  • Timothy Chase // August 17, 2009 at 4:47 am

    David B. Benson wrote:

    Not clear that there was a single common ancestor. I’ve seen one paper offering the suggestion of multiple independent abiogenesis events.

    If you are speaking of the last common ancestor of archaea, eukarya and bacteria, actually we do, although there were some doubts:

    Surprisingly, the central components of these systems (DNA polymerases, primases and replicative helicases) are either unrelated or, at least, not orthologous in archaebacteria and eubacteria.

    On the origin of genomes and cells within inorganic compartments
    Eugene V. Koonin and William Martin
    Trends Genet. 2005 Dec;21(12):647-54. Epub 2005 Oct 11
    http://www.molevol.de/publications/135.pdf

    … but as I pointed out earlier — in what you are responding to — at least as of 2006, and we are confident that the last universal common ancestor of ancestor of archaea, eukarya and bacteria was already using a spiral, open-ring AAA+ assembly for the initiation of the replication of DNA.

    I quoted:

    This model clarifies how DnaA engages and unwinds bacterial origins and suggests that additional, regulatory AAA+ proteins engage DnaA at filament ends. Eukaryotic and archaeal initiators also have the structural elements that promote open-helix formation, indicating that a spiral, open-ring AAA+ assembly forms the core element of initiators in all domains of life.

    Jan P Erzberger, Melissa L Mott & James M Berger (2006) Structural basis for ATP-dependent DnaA assembly and replication-origin remodeling, Nature Structural & Molecular Biology – 13, 676 – 683 (2006)

    … but continuing with Koonin:

    This contrasts the basic unity and conservation among the major proteins of the translation and transcription systems. Thus, LUCA is inferred to have had an advanced translation system that resembled modern ones in its principal features, but lacked a double-stranded, replicating DNA genome, possessing an RNA-based replication system instead.

    However, several other components of the DNA replication machinery, such as the sliding clamp plus the clamp loader ATPase and the DNA ligase, as well as enzymes of DNA precursor biosynthesis – ribonucleotide reductase and thymidylate kinase – are homologous in all prokaryotes, which led to the proposal that LUCA had a retrovirus-like replication cycle.

    On the origin of genomes and cells within inorganic compartments
    Eugene V. Koonin and William Martin
    Trends Genet. 2005 Dec;21(12):647-54. Epub 2005 Oct 11
    http://www.molevol.de/publications/135.pdf

    … we see that there was further evidence — some of which would appear to provide further details regarding the transition from the RNA to the DNA world.

    However, if you go back much further than the last universal common ancestor between archaea, eukarya and bacteria, it is likely that the last universal common ancestor becomes ill-defined even as a matter of “principle” insofar as lateral gene transfer becomes dominant. (For a short piece on this please see Phylogenetic Classification and the Universal Tree by W. Ford Doolittle.) But then in a certain sense, in the final analysis the last universal common ancestor would be the community that engaged such rampant lateral gene transfer.

    Perhaps this was what you were thinking of? But if that were the case it would be a little difficult to square it with this earlier statement:

    In any case, viruses are clearly parasites which evolved later, IMHO.

    Lateral gene transfer gene transfer requires mechanisms for lateral gene transfer, and the dominant ones involve either viruses (bacteriophages) or virus-like elements (group I and II introns, plasmids and retroplasmids, rolling-circle DNA transposons, etc.) if I am not mistaken.
    *
    David B. Benson wrote:

    I’ve seen one paper offering the suggestion of multiple independent abiogenesis events.

    It might help to figure out what they meant (e.g., that life existed for a while and then was wiped out) if you had a quote and reference. However, for example, while there are differences in codon dialects — where codon usage is necessarily strongly conserved, phylogentic analysis has shown that these are related and descended from a common ancestral code.

    Please see page 51 of:

    Rewiring the Keyboard: Evolvability of the Genetic Code
    Nat Rev Genet. 2001 Jan;2(1):49-58.
    http://bayes.colorado.edu/Papers/rewiring.pdf

    … for the tree itself. This indicates for all intents and purposes a common origin for all extant life. Although things might be a little more problematic if you include viruses. (And actually I would.)
    *
    David B. Benson wrote:

    More important, in my view, is planetary embryology: …

    For me it was more of an example of how you might do better at sourcing the reasons for your opinions. You have improved somewhat.

  • Mark // August 17, 2009 at 7:10 am

    ^ What he said. ^

  • Timothy Chase // August 17, 2009 at 7:44 am

    Alright, let’s look at the “planetary embryology” …

    David B. Benson wrote:

    More important, in my view, is planetary embryology:
    http://www.nature.com/nature/journal/v451/n7176/full/nature06582.html
    with the figure describing the proto-Terra-proto-Luna impact results being
    http://www.nature.com/nature/journal/v451/n7176/fig_tab/nature06582_F2.html
    and so a mantle quite unlike that of Venus. Of additional interest are the comments regarding plate tectonics; it seems it need not have happened. (If not to deep sea smokers.)

    Regarding the impact responsible for the creation of the moon the article states:

    The likely dominance ofthe embryos as building-blocks for Earth implies the predominance of giant impacts. We should not think of Earth’s formation as the steady accumulation of mass but rather as a series of infrequent, highly traumatic events separated by periods of cooling and healing. The largest, and possibly the last, of these events is thought to have been responsible for the formation of the Moon (Fig. 2). Recent isotopic evidence now dates this event at as a much as 100 million years after the origin of the Solar System. Many features of the event would also apply to earlier non-lunar-forming events, except that those would have been less extreme.

    It seems that the impact responsible for the formation of the moon wasn’t entirely unique. And thus we have actually little reason to believe that its long-term effect upon the earth’s core is actually that unusual.

    It does however state in the next to last paragraph:

    We understand why Earth’s mantle convects: there is no alternative mechanism for eliminating heat. However, we do not understand why Earth has plate tectonics. It is sometimes described as merely a property of the particular form that mantle convection takes on our planet, but this begs the question. Plate tectonics is neither mandatory nor common (there is no clear evidence of its existence on any other planet sofar).

    … but the statement that, “there is no clear evidence of its existence on any other planet sofar” isn’t terribly informative as the rocky planets we are limited to consist of Mercury, Venus, Earth and Mars. Moreover, in the case of Venus there is good reason to believe that runaway global warming baked whatever moisture existed in its rocks right out of them, making the lithosphere so brittle that it is no longer capable of earth-like plate tectonics — and simply suffers from catastrophic overturn every several hundred million years — as evidenced by impact craters — which show a uniform and relatively young age over the planetary surface.

    Please see for example:

    Moresi, L. Solomatov, V. (1998) Mantle convection with a brittle lithosphere: thoughts on the global tectonic styles of the Earth and Venus, Geophysical Journal International, Vol 133; Number 3, pages 669-682
    http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.30.5989&rep=rep1&type=pdf

    As for Mars, the planet is much smaller, and thus while it may still have a liquid core (I believe there is some evidence that even the Moon might still have one), there is little reason to believe that it would be sufficient for driving some sort of plate tectonics. And Mercury? I will leave that for someone else.

  • Barton Paul Levenson // August 17, 2009 at 8:50 am

    David writes:

    I’ve seen one paper offering the suggestion of multiple independent abiogenesis events.

    I don’t believe it. You wouldn’t get the same biochemistry and the same genetic code twice. Too unlikely.

    http://BartonPaulLevenson.com/Combo.html

  • Mark // August 17, 2009 at 1:36 pm

    I believe that there could be one paper offering the suggestion of multiple independent abiogenesis events.

    Mind you, I’ve seen one paper offer the opinion that the sun is made of iron.

  • Andrew Dodds // August 17, 2009 at 2:02 pm

    David/Timothy -

    I suspect (and if anyone wants to fund me in research for a few years might even be able to demonstrate) that for any rocky planet in the habitable zone, you will end up with liquid water oceans with land.

    This is based on -

    - If there is too much water (waterworld scenario), there will be little CO2 drawdown by erosion, and hence a large greenhouse effect, and large scale UV-driven dissociation of water to hydrogen and oxygen in the heated/enlarged atmosphere. Hence some landmasses will always be seen.

    - CO2 removal by chemical weathering is temperature dependent, so as soon as you have mountains you will tend to get temperatures stabilized by the CO2-thermometer effect

    - So your initial conditions can vary a lot to get to the same result; the main constraints would be to make sure the planet didn’t do a Venus, or freeze solid.

  • Timothy Chase // August 17, 2009 at 3:23 pm

    Mark wrote:

    I believe that there could be one paper offering the suggestion of multiple independent abiogenesis events.

    Mind you, I’ve seen one paper offer the opinion that the sun is made of iron.

    Perhaps.

    But I would be careful: I am beginning to think that we are dealing with some sort of wizard — and sometimes he manufactures things entirely out of thin air.

  • Mark // August 17, 2009 at 5:09 pm

    Not entirely impossible, Tim.

    But it is just as applicable to say “and so what if there’s one paper?” because you can find papers out there that say weird things we KNOW are wrong. Therefore the existence of one paper really doesn’t add anything to the discussion.

    Especially since it remains uncited.

  • Horatio Algeranon // August 17, 2009 at 6:25 pm

    Jabberbloggy

  • Timothy Chase // August 17, 2009 at 8:45 pm

    Mark wrote:

    But it is just as applicable to say “and so what if there’s one paper?” because you can find papers out there that say weird things we KNOW are wrong. Therefore the existence of one paper really doesn’t add anything to the discussion.

    Especially since it remains uncited.

    Right on all counts.

    The following can easily be interpreted as permitting multiple abiogenesis events:

    … If and only if this assumption holds, however, can we speak of organismal lineages and corresponding phylogenetic trees. But the assumption automatically makes the universal ancestor an organism that itself had a lineage, a discrete genealogy.

    The further back in evolutionary time we look, the more the notion of an “organismal lineage”—indeed, the very definition of “organism” itself—comes into question. It is time to release this notion of organismal lineages altogether and see where that leaves us.

    Carl Woese (9 June 1998) The universal ancestor, PNAS, vol. 95 no. 12 6854-6859
    http://www.pnas.org/content/95/12/6854.full

    However, he is in no small part speaking of lateral gene transfer as can be seen by the beginning of the abstract:

    A genetic annealing model for the universal ancestor of all extant life is presented; the name of the model derives from its resemblance to physical annealing. The scenario pictured starts when “genetic temperatures” were very high, cellular entities (progenotes) were very simple, and information processing systems were inaccurate. Initially, both mutation rate and lateral gene transfer levels were elevated. The latter was pandemic and pervasive to the extent that it, not vertical inheritance, defined the evolutionary dynamic. As increasingly complex and precise biological structures and processes evolved, both the mutation rate and the scope and level of lateral gene transfer, i.e., evolutionary temperature, dropped, and the evolutionary dynamic gradually became that characteristic of modern cells.

    ibid.

    Nevertheless, this particular sentence can be interpretted as supporting the idea of multiple abiogenesis events: “The further back in evolutionary time we look, the more the notion of an ‘organismal lineage’—indeed, the very definition of ‘organism’ itself—comes into question.” But the reason why Woese thinks it possible is because life was so simple that it would have barely qualified as life.

    Alternatively there is the argument that abiogenesis occured several times, but in all but one the lineages went extinct:

    ABSTRACT There is some indication that life may have originated readily under primitive earth conditions. If there were multiple origins of life, the result could have been a polyphyletic biota today. Using simple stochastic models for diversification and extinction,-we conclude: (i) the probability of survival of life is low unless there are multiple origins, and (ii) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior.

    D M Raup and J W Valentine (May 1, 1983) Multiple origins of life, PNAS vol. 80 no. 10 2981-2984
    http://www.pnas.org/content/80/10/2981.abstract

    … and I have heard that before.

    But I believe the argument by Woese is closer to what David was suggesting. And actually this is part of what I had in mind when I stated “This indicates for all intents and purposes a common origin for all extant life” as I wouldn’t have otherwise so qualified it.

    Once you get down to the level where the distinction between life and lifelessness becomes blurred — as it must — it becomes difficult to argue that there was any one single event during which life was created. But presumably the chemistry would have been much the same and so would have been the products of that chemistry. So I stand by my estimate of its import.

  • David B. Benson // August 17, 2009 at 10:20 pm

    Timothy Chase // August 17, 2009 at 1:55 am — The paper was in Scientific American several years ago. Later work on DNA certainly suggests a single common ancestor. In any case, hardly relevant to the question I now reformulate as

    likelihood of abiogenesis and life survival for at least 4 billion years.

    I still argue that forming a double planet (Terra-Luna) is both unlikely and important. The chemical composition of Terra is enhanced in core and deficient in mantle in comparison to planets without such an impact. This might be important for plate tectonics, without which no deep sea smokers.

    Moreover, it also preserved high rotation rate. Venus lacks that, likely due to a series of unfortunate collisions during/after formation. Without a high rotation rate the surface would be very windy, not conducive to photosynthesis. Whether tides were important or not is unknown, but some have conjectured so.

    Unicellular organism can certainly remove CO2 and sequester the carbon away from the active carbon cycle; algae do it all the time. What is known for Terra is the oxygen catastrophe about 2.4 billion years ago, thought to be the result of photosynthesis by cyanobacteria, roughly
    CO2 + photons –> C + O2
    with the result C not appreciably being later oxidized. Hence, no runaway greenhouse.

    Andrew Dodds // August 17, 2009 at 2:02 pm — You might be correct for planets with plate tectonics. Not so clear without that. Anyway, later Terra did freeze over, almost completely:
    http://en.wikipedia.org/wiki/Snowball_Earth
    according to some. Could not freeze solid due to geothermal heat.

  • David Gould // August 18, 2009 at 12:35 am

    There might have been multiple abiogenesis events, and then the most successful ‘family’ won, which would mean that after a relatively short period of time there would only be one genetic code.

    If life pretty much always arises under X conditions and X conditions existed at multiple places on the earth simultaneously, then – especially if there were gaps of inhospitability between these places – there is a reasonable possibility of multiple events occurring.

    I do not know whether this is what happened or not – I would guess no. But it is not an unreasonable proposition.

  • Ray Ladbury // August 18, 2009 at 1:25 am

    Horatio, Now that was just awesome!

  • David B. Benson // August 18, 2009 at 1:41 am

    David Gould // August 18, 2009 at 12:35 am — Yes, a distinct possiblity, once the requirements are met. I opine that meeting all those requirements (whatever those might be) is quite, quite rare. This is largely on the grounds of the improbability of the formation of suitably Terra-like planets orbiting suitably sun-like stars in otherwise hospitable portions of a galaxy.

    Consider the random nature of planetary formation:
    http://www.scholarpedia.org/article/Planetary_formation_and_migration

  • David Gould // August 18, 2009 at 4:54 am

    But if Terra met those requirements – and we know with 100 per cent certainty that it did! – there is no reason to suppose that it only met those conditions in one singular spot. After all, most condition sets occur multiple times on the earth – for example, more than one ocean vent.

    That says nothing about how rare the conditions are in planetary terms, though – ie, how often planets with those conditions will occur.

    I personally do not think that life is extremely rare – it will have arisen quite a few times in our galaxy over the past 5 billion years (but not millions of times, and possibly not even thousands of times).

    Intelligent life, on the other hand, would be quite rare indeed, I suspect.

  • Hank Roberts // August 18, 2009 at 4:58 am

    Is this basically the same as the original Peter Ward/Donald Brownlee argument (_Rare_Earth_)? (Before he came up with Medea instead of Gaia?)

  • Mark // August 18, 2009 at 8:08 am

    We can’t say that this bit of the basic block of life was from the same abiogenetic event as all the other bits in the basic blocks.

    We do, after all, have the observed FACT that gene transfer outside standard biological processes happen when bacteria take DNA segments from other organisms that have not been common ancestors by the standard tree of life (which isn’t really all that tree-like) for billions of years.

    So who is to say that some organism grew up with one event as its progenitor and create A. Another one in a different pool from another event created GT. And a third created in a different event C.

    And they all did very well.

    And DNA was invented when all three creations of different events got together and found out that they could easily replicate with this new information as a gestalt being.

    DNA.

  • Timothy Chase // August 18, 2009 at 8:42 am

    David B. Benson wrote:

    I still argue that forming a double planet (Terra-Luna) is both unlikely and important. The chemical composition of Terra is enhanced in core and deficient in mantle in comparison to planets without such an impact. This might be important for plate tectonics, without which no deep sea smokers.

    Quoting from the paper that you yourself directed us to:

    The likely dominance ofthe embryos as building-blocks for Earth implies the predominance of giant impacts. We should not think of Earth’s formation as the steady accumulation of mass but rather as a series of infrequent, highly traumatic events separated by periods of cooling and healing. The largest, and possibly the last, of these events is thought to have been responsible for the formation of the Moon (Fig. 2).

    … giant impacts were common.

    The largest was what resulted in the Moon, but there does not seem to be any reason to think that it was highly unusual. Unlikely? Perhaps. But are we speaking of one in three, one in ten, one in a hundred…? As the article itself points out, giant impacts are common. And I would presume more common, especially towards the end of planet-formation — as the smaller bodies would have already collided with the larger bodies — and the latter would be all that is left.

    David B. Benson wrote:

    Moreover, it also preserved high rotation rate. Venus lacks that, likely due to a series of unfortunate collisions during/after formation. Without a high rotation rate the surface would be very windy, not conducive to photosynthesis. Whether tides were important or not is unknown, but some have conjectured so.

    Venus lacks… due to a series of unfortunate collisions… now it is beginning to sound like Venus is the unusual case, not the earth. Well, both earth and Mars have nearly the same rate of rotation…

    David B. Benson wrote:

    Unicellular organism can certainly remove CO2 and sequester the carbon away from the active carbon cycle; algae do it all the time. What is known for Terra is the oxygen catastrophe about 2.4 billion years ago, thought to be the result of photosynthesis by cyanobacteria, roughly
    CO2 + photons –> C + O2
    with the result C not appreciably being later oxidized.

    “Unicellular organism can certainly remove CO2 and sequester the carbon…”

    I believe I acknowledged as much when I referred to their being shallow carbon pools.

    “… sequester the carbon away from the active carbon cycle…”

    What do you mean by “active carbon cycle”?

    If carbon is in the ocean or the soil is it in the “active carbon cycle”? If it is “sequestered” in a tree is in the “active carbon cycle”?

    I notice that you are still providing no numbers and no citations on the rates of the relevant carbon sinks or sources. Obviously new photosynthetic bacteria which produce oxygen from carbon dioxide will shift the balance — where even though they are a shallow carbon pool, they are a new carbon pool. Much like a new forest. But when forest is no longer growing it is no longer acting as a net sink. And when a tree dies it becomes source rather than a since.

    Likewise, if a shallow carbon pool were to expand it would shift the balance of carbon away from other shallow carbon pools. However, oxygen is highly volatile and corrosive. As such it has to be constantly replentished — which is why if we see an atmosphere with high levels of oxygen strong evidence of life.

    As such, it would seem that the carbon being temporarily “sequestered” would in fact be later oxidized, but that further oxygen would be produced to replace the oxygen used up in the process of oxidization. This is afterall why they refer to it as a “carbon cycle.” Of course there is one other possibility as far as algae “sequestering” carbon — and that would be if upon dying it didn’t undergo organic decay — perhaps as the result of sinking to the bottom of the ocean — preferably beyond the reaches of other bacteria. Do you have any evidence that this was a major factor? Numbers? Sources?

    Frankly, when you state:

    Alas, no. The geochemical/geophysical processes would continue to outgas CO2 “forever”. Exposed ultramafic rock ewill eventually form carbonates, removing CO2, but he reaction rates are quite slow. Need biological organisms to add CO2 removing energy and processes.

    … it begins to sound like there is some sort of limitless supply of carbon dioxide being spewed out by — a giant tail pipe? If one contemplates it long enough it seems rather comical.

    Do you have any numbers? Do you have any cites….?

  • Timothy Chase // August 18, 2009 at 3:01 pm

    Hank Roberts wrote:

    Is this basically the same as the original Peter Ward/Donald Brownlee argument (_Rare_Earth_)? (Before he came up with Medea instead of Gaia?)

    No. Peter Ward and Donald Brownlee argue that complex (multicellular) life is uncommon. And frankly I have no argument with that.

    However, David B. Benson argues that even bacterial life is extremely uncommon on the basis of… possibly the idea that earth-like plate tectonics is unusual — on the basis of particularly large collisions in the origin of a planet — the type that would cause “Terra to be enriched in core and deficient in mantle in comparison to Venus” is unusual. Not that he can actually argue that such collisions are particularly unusual, I suspect. Well, actually I believe it is possible for him to argue that as it is possible for him to argue anything — but just not support it.

    At other times he argues that bacteria might actually come into existence but not quickly enough for a planet to avoid a Venus-like fate — except under very rare circumstances. However, he does not care to consider how such bacterial life might actually come into existence — and thus support any of his claims about how unlikely it is — or how unlikely it is that such bacteria would arise quickly enough to keep a planet from suffering the fate of Venus.

    And beyond that? He has an occasional cite, one which suggests that it may be possible that earth-like plate tectonics is unusual — but essentially on the basis of its being “unusual” (1 in 4) among the rocky planets that we have examined so far.

    Oh well. Still I would say that this goose chase has been rather productive. I have gotten a fair number of PDFs out of it while trying to look up the answers to various questions, identified some points and connections I wasn’t aware of previously, and I have written some material that may be of use to me later.

    Besides, there are few things I would care to think more about than the origin (and evolution) of life. One of the three big questions at least as far as I am concerned. And the one that I personally find most fascinating.

  • Andrew Dodds // August 18, 2009 at 3:48 pm

    Timothy -

    I don’t actually see plate tectonics as very important; the evidence is, as far as I remember, that plate tectonics only really got going 2.5-3 Ga ago; Archean greenstone belts seem to represent a different tectonic style. Some sort of resurfacing is probably required for a stable climate; plate tectonics is one sort.

    The whole double-planet thing is more interesting – it looks like the moon plays a role in stabilizing the rotation axis of the Earth, which could be important over geological timescales. However, such moons may not be that rare.

    I’ve sometimes thought that an Earth-sized moon of a gas giant in the habitable zone could be even more stable. Wonder if it’s been modelled… and if the inhabitants of such a moon would regard the orbits/inclinations of non-moons as far too unstable to support complex life..

  • Timothy Chase // August 18, 2009 at 3:49 pm

    PS

    And now I have ordered the 2nd edition of “The RNA World.” Normally $120 but got it for $25. Ran across it by accident the day before yesterday, I believe. Hard cover. A similar purchase a couple of years ago (“The Implicit Genome”) was for a paperback.

  • Timothy Chase // August 18, 2009 at 4:10 pm

    Andrew Dodds wrote:

    The whole double-planet thing is more interesting – it looks like the moon plays a role in stabilizing the rotation axis of the Earth, which could be important over geological timescales. However, such moons may not be that rare.

    I remember wondering how important it might be in “stirring” the molten core by means of tidal forces. But I don’t have the background for making such calculations myself. However, I believe that the molten core is what generates the magnetic field and may protect our atmosphere from the solar wind.

    Then again, Venus would seem to be a counter-example to that — but its atmosphere might be maintained nowadays by the catastrophic turnover of its surface every few hundred million years. How it maintains an atmospheric density so well above our own with roughly a comparable gravitational field is beyound me.

    Anyway, I have a final for the summer quarter in one class today. And I have as of yet to study.

  • Timothy Chase // August 18, 2009 at 4:13 pm

    PS

    “beyound” was some sort of typo… Gruβ Gott! I know better than to spell like that.

  • TrueSceptic // August 18, 2009 at 5:10 pm

    For anyone who wants some amusement, I can strongly recommend the wonderful Denial Depot.

    Thanks to Frank Bi for the tip.

  • Gavin's Pussycat // August 18, 2009 at 5:53 pm

    … it begins to sound like there is some sort of limitless supply of
    carbon dioxide being spewed out by — a giant tail pipe? If one
    contemplates it long enough it seems rather comical.

    David, isn’t the Venus atmosphere a good first guess at the size of this supply?

  • Hank Roberts // August 18, 2009 at 6:30 pm

    > Venus … atmosphere

    http://deepblue.lib.umich.edu/handle/2027.42/24204

    Hydrogen gets driven off at the top, leaving the oxygen to combine with what’s left.

    I vaguely recall reading somewhere recently that Earth may have gotten rid of a lot of carbon in a large collision, perhaps the one that formed the Moon, based on suggestions that the backrground level of carbon is rather higher in the rest of the Solar system.

    Not this, but it’s a hint:
    http://dx.doi.org/10.1016/j.pss.2008.02.007

  • Hank Roberts // August 18, 2009 at 6:40 pm

    http://scienceblogs.com/islandofdoubt/2009/08/i_wish_they_were_right.php

    http://www.americanprogress.org/cartoons/2009/08/img/081709.jpg

  • Timothy Chase // August 18, 2009 at 6:43 pm

    Gavin’s Pussycat wrote:

    David, isn’t the Venus atmosphere a good first guess at the size of this supply?

    I will keep this short.

    I would agree — and I had considered that. However, wouldn’t you think that most of that carbon is locked up in rock — unless that rock undergoes sublimation as the result of a runaway greenhouse effect? That is in fact the explanation that I have run across.

    Try the search terms “venus carbon dioxide sublimation” in Google minus the quotes. (I would prefer a tech reference — but don’t have the time at the moment. Yet one really should search for alternate explanations. Maybe by adding “origin” and doing a minus on the “sublimation.”)

    In fact, if I remember correctly, there is evidence (in the upper atmosphere of Venus — hydrogen? but I thought that would escape — but I would try Science Daily, get the name of the author and the year of the study, pdf or do it in Scholar, include another search term for the subject and page through the results) for its past oceans. And the runaway greenhouse effect was presumably triggered by Venus receiving a somewhat higher amount of solar radiation triggering a runaway greenhouse effect.

    This sublimated the rock at the surface, releasing the carbon. Likewise it resulted in the dissociation of oxygen and hydrogen. The oxygen combined with the carbon, resulting in the dense carbon dioxide atmosphere.

    Now to release the carbon from our rocks would presumably require a similar sort of event — or alternatively a great deal of vulcanism. And according to a recent post by Tamino, volcanoes are actually poor sources of carbon dioxide — even supervolcanoes.

    Unless — I would presume — they set off large deposits of methane cathrates. Then again, in an anaerobic atmosphere methane would be much slower to degrade.

  • Timothy Chase // August 18, 2009 at 7:06 pm

    Not a tech paper, not sure one is available as of yet, but it would appear Venus had plate tectonics…

    Venus Express has charted the first map of Venus’s southern hemisphere at infrared wavelengths. The new map hints that our neighbouring world may once have been more Earth-like, with both, a plate tectonics system and an ocean of water….

    “This is not proof, but it is consistent. All we can really say at the moment is that the plateau rocks look different from elsewhere,” says Nils Müller at the Joint Planetary Interior Physics Research Group of the University Münster and DLR Berlin, who headed the mapping efforts.
    New Map Hints At Venus’s Wet, Volcanic Past
    ScienceDaily (July 15, 2009)
    http://www.sciencedaily.com/releases/2009/07/090714085818.htm

  • Timothy Chase // August 18, 2009 at 7:37 pm

    Different isotopes of hydrogen in the upper atmosphere as evidence of early oceans on Venus:

    Donahue and his colleagues base their report on the chemical evidence that water molecules leave behind when they split apart and leave the atmosphere of a planet. This chemical signature comes from the abundance of two atoms – hydrogen and its less abundant isotope deuterium, which has twice hydrogen’s mass. From 1978 through 1980, Pioneer Venus recorded the ratio of deuterium to hydrogen in the planet’s upper atmosphere.

    New evidence of ancient sea on Venus
    April 3, 1993 by Ron Cowen
    http://findarticles.com/p/articles/mi_m1200/is_n14_v143/ai_13719989/

  • Hank Roberts // August 18, 2009 at 8:54 pm

    Environ. Res. Lett. 4 (April-June 2009) 024011
    doi:10.1088/1748-9326/4/2/024011

    Does sea ice influence Greenland ice sheet surface-melt?

    Published 19 June 2009

    Abstract. Recent decreases in Arctic sea ice and increases in Greenland ice sheet surface-melt may have global impacts, but the interactions between these two processes are unknown. Using microwave satellite data, we explore the spatial and temporal covariance of sea ice extent and ice sheet surface-melt around Greenland from 1979 to 2007. Significant covariance is discovered in several loci in the late summer, with the strongest covariance in western Greenland, particularly in the southwest (Kangerlussuaq). In this region, wind direction patterns and a statistical lag analysis of ice retreat/advance and surface-melt event timings suggest that sea ice extent change is a potential driver of ice sheet melt. Here, late summer wind directions facilitate onshore advection of ocean heat, and enhanced melting on the ice sheet commonly occurs after reductions in offshore sea ice. Hence, this study identifies for the first time the covariability patterns of sea ice and ice sheet melt and suggests that a retreating sea ice margin may enhance melting over the ice sheet.

  • Timothy Chase // August 18, 2009 at 8:59 pm

    Runaway greenhouse effect on Venus was a function of water vapor and solar flux, not carbon dioxide:

    Calculations with a fully saturated, cloud-free, climate model indicate that the critical solar flux required to trigger a runaway greenhouse is 1.4 times the values at Earth’s orbit, or about the same as the flux at Venus’ orbit early in Solar System history. This result is nearly independent of the amount of CO2 in the atmosphere, but is sensitive to the H2O absorption coefficient in the 8- to 12-μm window region.

    pg.488 of:

    James F. Kasting (1988) Runaway and Moist Greenhouse Atmospheres and the Evolution of Earth and Venus, Icarus 74, 472-494
    http://www.geosc.psu.edu/~kasting/Meteo_466/Readings/Icarus_88.pdf

    Regarding the sublimation of rock:

    The critical solar flux above which water is rapidly lost could be as low as 1.1 So. The surface temperature of a runaway greenhouse atmosphere containing a full ocean’s worth of water would have been in excess of 1500°K-above the solidus for silicate rocks.

    ibid., abstract

  • Timothy Chase // August 18, 2009 at 10:59 pm

    The carbon dioxide in Venus’s atmosphere is roughly equal to that in Earth’s carbonate rocks:

    Venus’s atmosphere is predominantly CO2, roughly equivalent to the amount of CO2 tied up in carbonate rocks on Earth, and is extremely dry, with about 30 ppm of H2O, corresponding to ~ 10^-3 of the water content of Earth’s atmosphere.

    pg. 175

    Baines, K.H. Atreya, S.K. Carlson, R.W. Crisp, D. Grinspoon, D. Russell, C.T. Schubert, G. Zahnle, K. (2007) Geophysical Monograph – American Geophysical Union, Numb 176, pages 171-190

    There is a strong possibility that it was the loss of water that resulted in the loss of carbon dioxide from Venus’s rocks. Likewise, it appears that the drying out of Venus’s rocks ultimately stopped plate tectonics (I presume with the drying out of its lithosphere making the rocks too brittle for that sort of thing), slowed the rate of core cooling and turned off Venus’s magnetic field:

    How did the atmosphere evolve to its present state if it was initially similar to Earth’s atmosphere with a substantial complement of water? A strong possibility is that an intense greenhouse effect led to the vaporization of all water on early Venus, followed by photodissociation of the water vapor at high altitudes and the escape of the released hydrogen into space. Without liquid water on its surface, CO2 could then not be sequestered in the surface rocks. This change in Venus’s atmosphere, if it occurred, would have triggered changes in the planet reaching all the way to its core. The loss of water would stop plate tectonics. This would have changed the style of mantle convection, slowed the rate of core cooling, and turned off the magnetic field.

    ibid.

  • Dano // August 18, 2009 at 11:00 pm

    Runaway greenhouse effect on Venus was a function of water vapor and solar flux, not carbon dioxide:

    Single 1988 reference, eh? Apparently the water that still exists in the atmosphere overwhelms the CO2. Bad news for us then when heating makes more water vapor. We’re doomed!

    Ah, well. Whaddya gonna do? Some people need to believe any ol’ set of silly fantasies to maintain their cognitive harmony…

    Best,

    D

  • Timothy Chase // August 18, 2009 at 11:33 pm

    Dano wrote:

    Single 1988 reference, eh?

    Actually judging from the 2007 I refered us to, the view expressed in the classic 1993 is more or less standard fair nowadays. You won’t see much discussion of things that are well-established in the science journals. And while the case for the 1988 analysis still isn’t considered conclusive it doesn’t seem to have any serious rivals.
    *
    Dano wrote:

    Apparently the water that still exists in the atmosphere overwhelms the CO2. Bad news for us then when heating makes more water vapor. We’re doomed!

    I know you are trying to be funny.

    However, this is where it gets interesting:

    At low values of Seff, Ts increases monotonically with increasing pCO2. However, CO2 increases alone are not able to trigger a runaway greenhouse. This behavior is in accord with the predictions of Kasting and Ackermann (1986), who studied the response of surface temperature to increased CO2 levels for Seff equal to 0.7 and 1.0. At values of Seff between 1.2 and 1.35 something unusual occurs: Ts decreaes as pCO2 increases from 0.2 to 10 bar, then increases once again at pCO2= 100 bar. The reason is that, at pCO2 = 10 bar, the increase in total surface pressure outstrips the increase in saturation vapor pressure caused by the greenhouse effect; hence, the surface water vapor mixing ration declines and the stratosphere dries out. A similar but less pronounced effect is predicted for Seff= 1 (Kasting and Ackerman 1986).

    page 483 of…

    James F. Kasting (1988) Runaway and Moist Greenhouse Atmospheres and the Evolution of Earth and Venus, Icarus 74, 472-494
    http://www.geosc.psu.edu/~kasting/Meteo_466/Readings/Icarus_88.pdf

    It is some paradoxical, but the runaway greenhouse effect on Venus was largely independent of its carbon dioxide. However, nowadays of course it is maintained by the carbon dioxide that resides in Venus’s atmosphere.

  • Timothy Chase // August 18, 2009 at 11:41 pm

    PS

    Last paragraph should have read, “It is somewhat paradoxical…”

  • David B. Benson // August 18, 2009 at 11:56 pm

    The present rotation period of Venus represents an equilibrium state between gravitational tidal locking by the Sun that tends to slow the rotation rate, and an atmospheric tide created by the solar heating of Venus’s thick atmosphere. When it formed from the solar nebula, Venus may have begun with a different rotation period and obliquity, then migrated to the current state because of chaotic spin changes caused by planetary perturbations and tidal effects on its dense atmosphere. This change in the rotation period likely took place over the course of billions of years.

    from
    http://en.wikipedia.org/wiki/Venus

    Same source suggests that lack of magnetosphere promoted hydrogen loss; positive feedback?

    Here is a quite different hypothesis of Venus formation:
    http://www.dailygalaxy.com/my_weblog/2008/02/did-a-big-bang.html

  • Timothy Chase // August 19, 2009 at 12:31 am

    David B. Benson wrote:

    Same source suggests that lack of magnetosphere promoted hydrogen loss; positive feedback?

    Presumably it is the magnetosphere that in large part protects the earth’s atmosphere. I am a little surprised that Venus is able to hold onto such a dense one. But hydrogen is of course more susceptible.
    *
    David B. Benson wrote:

    Here is a quite different hypothesis of Venus formation:
    http://www.dailygalaxy.com/my_weblog/2008/02/did-a-big-bang.html

    Huh. That is one I have never heard of before.

  • David B. Benson // August 19, 2009 at 12:32 am

    “… the early solar system was a violent place …”
    from
    First Comet Dust On Earth Reveals Clues To Solar System
    http://www.sciencedaily.com/releases/2006/12/061214160651.htm

  • dhogaza // August 19, 2009 at 1:01 am

    For those of you who remember the CO2-snow-in-Antarctica fiasco at WUWT, and have noticed that Steven Goddard no longer posts there …

    REPLY: I took him to task over the post on the possibility of CO2 freezing solid at the South Pole. He left in a huff rather than own up to the mistake. So, he doesn’t guest post here anymore. – Anthony

    That’s hilarious, Goddard insisted to the very end that he was right, physical chemistry textbooks wrong…

  • David B. Benson // August 19, 2009 at 1:47 am

    Planet-formation model indicates Earthlike planets might be common:
    http://www.washington.edu/newsroom/news/2003archive/12-03archive/k121003.html
    is now 5.5 years old and probably needs to be redone in light of
    3D Modeling Shakes Up Planet-Formation Theory:
    http://www.space.com/scienceastronomy/090127-st-planet-formation.html
    Giant Planet Formation by Disk Instability: A Comparison Simulation With An Improved Radiative Scheme:
    http://arxiv.org/abs/0907.4213

    But even so, these results certainly have a tentative feel about the.
    Planet Formation Page:
    http://www.astro.washington.edu/users/rory/research/formation/

  • Mark // August 19, 2009 at 9:55 am

    Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.

    Water is removed because the Hydrogen escapes easily and when water is split, the H2 leaves the O all alone and so you get an oxidising reaction taking the O away. And less H2O as a result.

    Any molecule that has light particles will disappear just as well.

    I think that there’s good proof for frequent renewal of the Venusian atmosphere because there shouldn’t be enough hanging around to make 90 atmospheres without it.

  • Mark // August 19, 2009 at 10:00 am

    “http://www.dailygalaxy.com/my_weblog/2008/02/did-a-big-bang.html”

    Huw’s hypothesis (it really is one at the moment, there’s no testability yet) isn’t new. Heck in the 30’s (IIRC) one very weird bloke figured that Jupiter ejected a venus-sized mass which walloped the inner planets a lot like Huw proposes. Huw just left out the impractical and impossible Jovian ejecta.

    The problem is that it isn’t needed and requires a lot of things to go “just right”.

    It may give insights or even be true, but only in the same vein as human intelligence could have started because we saw Caledonian Crows use tools and we aped them (sorry for the pun).

  • Mark // August 19, 2009 at 10:01 am

    PS the “contra-rotating” problem is no problem.

    Axial tilt can go 180 degrees.

    And what happens when you have your poles reversed?

    Yup, you get one that looks to be spinning the wrong way.

  • Barton Paul Levenson // August 19, 2009 at 11:11 am

    Mark:

    I think that there’s good proof for frequent renewal of the Venusian atmosphere because there shouldn’t be enough hanging around to make 90 atmospheres without it.

    CO2, with its molecular weight of 44, cannot noticeably disappear through Jeans escape in the normal lifetime of a planet (c. 10^10 years).

  • Mark // August 19, 2009 at 12:49 pm

    “CO2, with its molecular weight of 44,”

    Uh, when it’s broken up, it is no longer 44.

    It’s one of 12 and two of 16.

    That was the point of that bit I said (and quote again):

    “Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.”

    See that?

    If a changed particle with an energy of, say 10ev hits a CO2 molecule, this is plenty enough to break ANY covalent bond.

    What happens when the binding of a molecule is broken?

    This is why water (molecular weight ~18) disappears so fast: it doesn’t STAY 18 very long. It gets ionised (binding energy <13eV) and becomes 2H (weight 1 each) which waddle off out into space. With no nearby 2H to combine with, the O on its own oxidizes with something else. Which means less water.

  • Hank Roberts // August 19, 2009 at 2:31 pm

    http://www.astronomynotes.com/solarsys/uvdissoc.gif

  • Timothy Chase // August 19, 2009 at 5:09 pm

    David B. Benson:

    But even so, these results certainly have a tentative feel about them.
    Planet Formation Page:
    http://www.astro.washington.edu/users/rory/research/formation/

    I should say!

    The letters look so big they might as well have been done with crayons.

  • Timothy Chase // August 19, 2009 at 5:37 pm

    Mark wrote:

    This is why water (molecular weight ~18) disappears so fast: it doesn’t STAY 18 very long. It gets ionised (binding energy <13eV) and becomes 2H (weight 1 each) which waddle off out into space. With no nearby 2H to combine with, the O on its own oxidizes with something else. Which means less water.

    Makes sense.

    Temperature proportional to the average molecular kinetic energy, molecules needing to exceed escape velocity, then the key — the Maxwell-Boltzmann, where the probability density function is proportional to (x^2)e^(-x^2). Of course in this exercise you would be concerned with cumulative probability, but qualitatively the results are the same: the likelihood of a more massive atom escaping is (roughly speaking) an exponential function of its mass and will fall much more rapidly than the inverse of the mass.

    Then there is that constant renewal of the atmosphere — which you mentioned — with the catastrophic overturn of the surface every few hundred million years. Being the non-expert that I am, it made sense to me that this would happen, but all I had to go on was my “common sense” which in my view counts for very little beyond a certain point.

  • Timothy Chase // August 19, 2009 at 5:51 pm

    PS

    So when we say that magnetospheres protect planetary atmospheres from stellar winds what we are really concerned with are gases with light atoms, and mostly only to the extent that these gases are high enough in the upper atmosphere that collisions with a stellar wind are likely to result in those atoms achieving escape velocity.

    So with the e-folding distance of water vapor being roughly 1.5 km in our atmospheric column, it would seem that we wouldn’t have to worry too much about the Earth’s atmosphere drying out if the magnetosphere suddenly shut off.

  • Timothy Chase // August 19, 2009 at 6:20 pm

    Mark wrote:

    Huw’s hypothesis (it really is one at the moment, there’s no testability yet) isn’t new. Heck in the 30’s (IIRC) one very weird bloke figured that Jupiter ejected a venus-sized mass which walloped the inner planets a lot like Huw proposes. Huw just left out the impractical and impossible Jovian ejecta.

    The problem is that it isn’t needed and requires a lot of things to go “just right”.

    And here I thought astronomers saw head-on collisions all the time. Something about the big guy preferring to shoot straight rather than spin things with a little english.

  • Hank Roberts // August 19, 2009 at 7:18 pm

    Speaking of hypotheticals, this guy standing on his head asks:
    http://johnquiggin.com/index.php/archives/2009/08/02/sane-republican-hunt/

  • Timothy Chase // August 19, 2009 at 7:35 pm

    Hank… regarding John Quiggin and the plate tectonics thing…

    Olde earth creationism was more early twentieth century. Since the 1960s it entered rapid decline, and nowadays if you are a creationist in the US chances are you are a young earth creationist. So plate tectonics is out. ‘nough said.

    • TrueSceptic // August 19, 2009 at 10:19 pm

      I rather like the quote, “So, these people believe the Universe was created after we domesticated the dog?” (paraphrase).

      Does anyone know who first said it?

  • David B. Benson // August 19, 2009 at 9:40 pm

    Work through about 1999 CE.
    Giant Impact Theory of the Origin of the Moon
    http://www.windows.ucar.edu/tour/link=/teacher_resources/impact_theory.html
    constrains initial conditions rather greatly.

    Different work though 2005 CE.
    ‘Mild’ collision spawned Earth’s moon
    http://sci.tech-archive.net/Archive/sci.geo.geology/2006-01/msg00229.html
    gives different, still restrictive, initial conditions.

    But the best, by far, is Joseph Spradley’s (Southwest Research Institute) presentation
    ASA2009Spradley.pdf
    at
    http://www.asa3.org/ASA/meetings/baylor2009/papers
    who offers the probability of 10^(-8) and argues my position better than I can.

  • Anna // August 19, 2009 at 11:58 pm

    In response to Hank’s recent request (at InIt) for an H.E. Taylor “week of global warming/climate destabilization news” widget, I made one which you can find and get the HTML for at warming101.com/hetaylor.

    TrueSkeptic, I see a Joe Nation making your point in Sept 2007, here.

  • David B. Benson // August 20, 2009 at 12:26 am

    In “Where Did The Moon Come From?” by Edward Belbruno & J. Richard Gott III
    http://arxiv.org/abs/astro-ph/0405372
    by making several simplifying assumption, the authors establish the high probability that if
    (1) a proto-planet forms at Terra’s L4 or L5 stable Lagange point, and if
    (2) it grows to about 1/10 proto-Terra’s mass over the right length of time
    then with high probability (0.25–0.5) it collides with proto-Terrra in a manner which matches many of the observed features of the actual Terra-Luna twin planet.

    This is an elegant paper which seems to have launched space probes but not yet otherwise been integrated into simulations of solar system formation.

  • Timothy Chase // August 20, 2009 at 12:48 am

    David B. Benson wrote:

    But the best, by far, is Joseph Spradley’s (Southwest Research Institute) presentation
    ASA2009Spradley.pdf
    at
    http://www.asa3.org/ASA/meetings/baylor2009/papers
    who offers the probability of 10^(-8) and argues my position better than I can.

    I do hope you are kidding.

    A slide presentation before the Christian “American Scientific Association”…? Which is more or less divided into those who accept some form of directed evolution vs. those who still can’t give up their childhood creationism?

    Am I supposed to regard that as having any weight?

    The “Ten Results of Glancing Collision”

    1. Greenhouse gases removed — with the author assuming that Earth’s early atmosphere was similar to Venus’s today? Venus’s atmosphere as it exists today appears to have been the product of runaway global warming due to increased solar radiance and runaway global warming — with carbon dioxide being sublimated from the silicates of its rocks.
    2. Implying that without the collision Earth would have been Mercury-like with its 700K days and 100K nights…? I don’t believe that even deserves a response.
    3. Stronger magnetic field from faster rotation and more massive iron core protecting life? I will leave that one for later — if we continue.
    4. Increased the length of the day and thus fewer hurricanes? Mars has a comparable length of day.
    5. More surface minerals for life? Perhaps. But who is to say that we wouldn’t have gotten something similar from other planetoids…? And what if the cloud that our third generation star formed from contained more of the heavier elements as the result of a more massive second generation star.
    6. Plate tectonics? Venus appears to have had it.
    7. Ocean enrichment with minerals caused by strong tides and fast rotating earth? I thought the author had said that fast rotation was a bad thing? And as for tides you could get that by placing the planet in closer proximity to a smaller star. And you would have more time for life to evolve.
    8. Slows the rotation, reducing hurricanes and optimizing climate? Yes — it presumably slowed the rotation to what we see with Mars. But I thought we had covered that in (4).
    9. Tides driving currents, moderating climate, clensing and oxygenating the waters? Concentrating nutrients in tidal ponds? Making possible the origin of life? Well, many of the members of ASA know quite well that life began in a garden. But who is to say that it didn’t occur around a white geothermal smoker — in fact evidence seems to point in that direction. Tide-enrichment (assuming the same couldn’t be accomplished with a smaller star and closer orbit) wouldn’t be an issue there I presume.
    10. Tilt of Earth stabilized? I would presume that there is no more reason to expect the Earth’s tilt to be more stable after a collision than before. Does he have any evidence to suggest otherwise?

    I do not have problems with religion.

    Religion and Science
    http://axismundi.hostzi.com/0/002.php

    I do have problems with religion cloaked as science. And I believe that slide presentation has crossed the boundary.

  • Timothy Chase // August 20, 2009 at 1:36 am

    David B. Benson pointed us to:

    In “Where Did The Moon Come From?” by Edward Belbruno & J. Richard Gott III
    http://arxiv.org/abs/astro-ph/0405372

    That does appear interesting. But as the English might say, “The maths elude me.” But of course the deficit is in my education, not the paper itself. I see it was published in a periodical devoted to astronomy:

    Belbruno, Edward; Gott, J. Richard, III (2005) Where Did the Moon Come From? The Astronomical Journal, Volume 129, Issue 3, pp. 1724-1745

    But why the Earth and not Venus? If what caused the formation was in some way related to the stability of L4 or L5?

  • Timothy Chase // August 20, 2009 at 1:41 am

    Correction in critique of Joseph Spradley’s slide show:

    1. Greenhouse gases removed — with the author assuming that Earth’s early atmosphere was similar to Venus’s today? Venus’s atmosphere as it exists today appears to have been the product of runaway global warming due to increased solar radiance and water vapor feedback [not "runaway global warming"] — with carbon dioxide being sublimated from the silicates of its rocks.
  • David B. Benson // August 20, 2009 at 2:10 am

    Timothy Chase // August 20, 2009 at 12:48 am — The presentation is based on the science and simulations as I previously have indicated. Some of the points are not that well thought out perhaps, but at least all the factors have been bought out.

    1. Greenhouse gas removed. Yes, such a collision removes the primordial atmosphere (whatever it was).

    2. Decent rotation rate required for equitable climate. Mercury is an extreme anti-example. So is Venus. That’s 50% of our small sample space.

    3. Magnetic field appearently important to avoid runaway greenhouse; we have been over that.

    4. Rotational slow down maybe important, dunno.

    5. Since nobody quite sure about abiogenesis, maybe the increased metalicity has been important. But yes, there was also the secondary bombardment some hundreds of millions of years later.

    6. Maybe Venus had plate tectonics. Of some interest for abiogenesis is the earlier comment that Terra’s plate tectonics did not start up until after around 3 billion years ago.

    7. Others have suggested that tides were important for abiogenesis; not unique to this author.

    8. Does seem redundant, does it not?

    9. Tides again. Certainly to be found in other sources for much the reasons listed here. And if Terra’s plate tectonics did not start until after 3 billion years ago, no early smokers as an enthalpy source for early metabolism; if life did not start until after 3 billion years ago, I have no explanation for end-Hadean banded iron formations.

    10. Yes, Luna stabilizes Terra’s tilt. This is well known amd other authors have pointed out that when Luna finally escapes, Terra’s tilt significantly increases, playing a havoc with weather and climate.

    I fear you are letting the venue stand in the way of an appreciation for the scientific content of this summary ppt. I view it as good, not as perfect.

  • David B. Benson // August 20, 2009 at 2:19 am

    Timothy Chase // August 20, 2009 at 1:36 am — Just read the text and avoid the math; that’s what I did, mostly, on first pass.

    But your question about why Terra and not Venus is a good one. The simplest answer is just chance; planetry formation appears to have a strong random component. Another is the earlier posted conjecture that Venus was formed by the collision of two (nearly) equi-sized planetoids, explaining quite neatly most of the unique features of Venus; again, just chance.

  • Timothy Chase // August 20, 2009 at 5:36 am

    David B. Benson wrote:

    1. Greenhouse gas removed. Yes, such a collision removes the primordial atmosphere (whatever it was).

    Possible. Possible it was added by the body that collided with us. In any case I pointed us to a source which states that the amount of carbon dioxide in Venus’s atmosphere is roughly equal to the amount that is locked up in our rocks. Moreover it and other sources support the point that the carbon dioxide in Venus’s rocks was sublimated as the result of the runaway greenhouse effect.

    Why do you prefer his slide presentation over peer reviewed science?

    2. Decent rotation rate required for equitable climate. Mercury is an extreme anti-example. So is Venus. That’s 50% of our small sample space.

    Fifty percent of our same space. So does this mean that we should assume that a decent rotation is rare? Perhaps a one in a million fortuitous event?

    That is the impression I get from his slide show.

    3. Magnetic field appearently important to avoid runaway greenhouse; we have been over that.

    Have we? I see it suggested that loss of the magnetic field resulted in hydrogen leaking away. However that dries out the atmosphere — reducing the level of water vapor — which means that it actually has the opposite effect. It cools the planet — but that is irrelevant once the carbon dioxide has been sublimated from Venus’s rocks.

    4. Rotational slow down maybe important, dunno.

    Might be. So why don’t we simply assume it is in the name of a greater good? It would appear that this is what the author of the slide presentation does.

    5. Since nobody quite sure about abiogenesis, maybe the increased metalicity has been important. But yes, there was also the secondary bombardment some hundreds of millions of years later.

    … and why don’t we just assume that such metalicity could not have just as easily resulted from a more massive second generation star leaving behind the nebula from which another, Sol-like star might form? We can do this in the name of the greater good as well. If it gives strength to those whose faith might otherwise faulter…

    6. Maybe Venus had plate tectonics. Of some interest for abiogenesis is the earlier comment that Terra’s plate tectonics did not start up until after around 3 billion years ago.

    Using the search term “billion years” I did not find any text to that effect. But maybe I missed it. As for Venus the evidence apparently strongly suggests it — as well as ancient oceans — given the ratio of deutrium to hydrogen. And ancient oceans do not suggest that it always had the same level of carbon dioxide as what it has at present. However, if the carbon dioxide were “in the atmosphere” absent a major collision then clearly it would never have had an ocean.

    7. Others have suggested that tides were important for abiogenesis; not unique to this author.

    8. Does seem redundant, does it not?

    His redundancy? Yes it does. But then again, that might fit the purpose of his presentation.

    No — it is not unique. However, in calculating just how fortuitous life on Earth is he simply assumes that this is the only way in which life could have arisen.

    9. Tides again. Certainly to be found in other sources for much the reasons listed here. And if Terra’s plate tectonics did not start until after 3 billion years ago, no early smokers as an enthalpy source for early metabolism; if life did not start until after 3 billion years ago, I have no explanation for end-Hadean banded iron formations.

    Even assuming there was no plate tectonics until after 3 billion years, why would you assume that there were no early smokers? The earth, after all was cooling down from a fairly hot state. Were there no underwater volcanoes? Nothing geothermal going on 3.8 billion years ago?

    10. Yes, Luna stabilizes Terra’s tilt. This is well known and other authors have pointed out that when Luna finally escapes, Terra’s tilt significantly increases, playing a havoc with weather and climate.

    It is possible. I would say probable, even. But I mostly find it in places like Wiki Answers and Yahoo. Other places say that it seems to. Some ascribe its stabilizing effect to tidal motions. Others ascribe the stability of the Earth’s tilt to the Earth’s own angular momentum. But let us assume that what stabilizes the Earth’s tilt is in fact the tidal. A wobble in its absence wouldn’t surprise me given our liquid then solid core. Conservation of angular momentum will insure a constant tilt of the surface only assuming the Earth were solid through and through.

    But what if we were around a less massive star? Its brightness falls off more rapidly than its mass, so to receive the same radiance we would have to be closer than what would be the case if its surface radiance were a constant, and we would be subject to a greater “solar” tidal force.

    I fear you are letting the venue stand in the way of an appreciation for the scientific content of this summary ppt. I view it as good, not as perfect.

    And I fear that you are letting your religious belief color your view of the PowerPoint presentation. There is no atheist science, no Christian science, no Moslem, no Buddhist, Hindu or Jewish science. There is human science, and it is our common heritage.

  • Timothy Chase // August 20, 2009 at 5:44 am

    Ps

    I have typed the following (or rather its equivalent) but somehow it was lost from the post — maybe due to inadvertent selection prior to typing something else:

    David B. Benson wrote:

    7. Others have suggested that tides were important for abiogenesis; not unique to this author.

    They have suggested it — but he simply assumes that it must have happened where tides would have presumably been important. Why?

  • Timothy Chase // August 20, 2009 at 6:07 am

    David B. Benson wrote:

    … Another is the earlier posted conjecture that Venus was formed by the collision of two (nearly) equi-sized planetoids, explaining quite neatly most of the unique features of Venus; again, just chance.

    A “head on,” purely inelastic, Velikovsky-like collision? I thought that your bringing that particular “theory” up was intended as humor.

    Do you know what would quite neatly explain all of the evidence? The big guy did it that way because that is the way he wanted it. In fact, if one wants to one can take that approach to any scientific question — but then one is no longer doing science.

  • Mark // August 20, 2009 at 10:15 am

    “1. Greenhouse gas removed. Yes, such a collision removes the primordial atmosphere (whatever it was).”

    Just like the primordial atmosphere of Earth was wiped out when we got walloped with another planet and the ejected mantle became Luna.

    Somehow we managed to get a water atmosphere afterward…

  • Mark // August 20, 2009 at 10:21 am

    “And here I thought astronomers saw head-on collisions all the time.”

    If you have Cosmos, watch the third (I think) episode.

    The short answer is:

    Collisions are seen all the time. However, Jupiter can’t just eject a rocky body. How does that body get the energy needed?

    When that object is ejected, how does it remove enough energy to have a hope of walloping into the earth?

    If it doesn’t and just gets jinxed into hitting, the odds of happening are, literally, astronomical. It would be like firing a pea from a trebuchet and getting the pea to land in an eggshell 50 miles away.

  • Mark // August 20, 2009 at 10:23 am

    “So with the e-folding distance of water vapor being roughly 1.5 km in our atmospheric column”

    Sigh.

    And when H2O is disassociated, what is the e-folding distance of Hydrogen au natural?

    Forget the weight of molecules. That can be broken no problem.

  • Mark // August 20, 2009 at 10:29 am

    “Being the non-expert that I am, it made sense to me that this would happen, but all I had to go on was my “common sense” which in my view counts for very little beyond a certain point.”

    All that’s needed is to find other evidence of either its occurrence in the past (the age of the surface of Venus is very low) or evidence that such a process happens (on Earth, we can see expanding ridges and subduction zones so can show evidence that we have plate tectonics).

    Until we can get probes to investigate the internal structure of Venus (same as we do for the earth) and last long enough to get a long history of signals of kinetic waves through the internal structure of Venus, all we have is the evident FACT of the youthfulness of Venus’ surface.

    If we can see a heavy, thick and fairly cool magma layer underneath the surface (especially if it contains a high proportion of metals), we then have evidence of how the turnover happens.

    Or we could get lucky and see it happen.

  • Barton Paul Levenson // August 20, 2009 at 11:15 am

    Mark writes:

    “CO2, with its molecular weight of 44,”

    Uh, when it’s broken up, it is no longer 44.

    It’s one of 12 and two of 16.

    That was the point of that bit I said (and quote again):

    “Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.”

    See that?

    Yes, I see it. It’s wrong. CO2 has no strong absorption bands in the ultraviolet, and the charged particle density isn’t enough to disassociate significant amounts of CO2 over geological time. I recommend checking out Marov and Grinspan’s “Venus” (1998) or the 1983 Venus compilation from the University of Arizona, both of which have extensive sections on upper-atmosphere chemistry and physics.

  • Barton Paul Levenson // August 20, 2009 at 11:27 am

    A paper in 1976 proposed that Mercury might be an escaped moon of Venus. One of the authors was Thomas C. van Flandern, who since then became a major flake, but the other was the Naval Observatory’s Robert S. Harrington, who did not. In any case, the paper passed peer review and was published in Icarus, the premier planetology journal.

  • Mark // August 20, 2009 at 1:25 pm

    “Yes, I see it. It’s wrong. CO2 has no strong absorption bands in the ultraviolet,”

    And who said that CO2 had to have strong absorption bands?

    You.

    Here again is what ***I*** said:

    “Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.”

    You seem to be creating your own reality and arguing it.

    Make hay, I suppose is your motto…

  • Andrew Dodds // August 20, 2009 at 1:31 pm

    BPL -

    Did find this whilst looking:

    http://articles.adsabs.harvard.edu//full/1977Ap%26SS..51..235K/0000235.000.html

    So even if Venus actually had a moon, disruption from the sun may have caused it to lose it. Have to say that a Mercury as moon of Venus appears unlikely, although if I recall correctly Mercury may well be in an unstable orbit.

  • Timothy Chase // August 20, 2009 at 2:55 pm

    Mark wrote:

    If it doesn’t and just gets jinxed into hitting, the odds of happening are, literally, astronomical. It would be like firing a pea from a trebuchet and getting the pea to land in an eggshell 50 miles away.

    Agreed. And not simply land in the eggshell, but land right in the center of the eggshell without tipping it over or cracking it in the process. How unlikely would it be, and surely there are more likely scenarios that would do just as well at explaining the same outcome.

    But then again, I was trying to be humorous at that point. Unfortunately it doesn’t always translate all that well to static text — unless one uses smileys — but then that is a bit like holding up a sign that says “Joke!” However, I figure it is worth the risk insofar as humor teaches us not only how to see things from different perspectives but how to rapidly shift from one perspective to another and see how they are related. I suspect that is an asset in human cognition no matter the domain.

  • Mark // August 20, 2009 at 4:33 pm

    “unless one uses smileys”

    I really preferred the IRC “” or “” than that bloody awful :-) or :-P. But we’ve all gone HTML, so we can’t use brackets any more.

    Kids today…

  • David B. Benson // August 20, 2009 at 10:49 pm

    Timothy Chase // August 20, 2009 at 5:36 am — Well, I seem to have pinched your nerve by simply linking to a ppt which, although with some flaws, reviews the evidence and some results. (1) Strictly speaking, I am an agnostic atheist and view myself as primarily a scientist; everything is contingent. I certainly didn’t pick the ppt for its venue. If I had known how badly you would misconstrue this, I’d not have linked it. [By the way, try a google search using "nortre dame astronomy". Why would I suggest that?] (2) Peer-reviewed science is fine, but so is the occasional review. Note I have oftern linked to Wikipeida as a place to start on a topic.] (3) The only planet which we are sure abiogenesis occurred is Terra. We need to understand the preconditions for that abiogenesis before even conjecturing if it is possible with different geological histories. (4) Several of the moons of Saturn are L4-L5 pairs of each other. This suggests something similar might have happened in the formation of Venus, the two bodies colliding; hence its lack of anything but the most modest rotation. Alternatively, the dense atmosphere helped slow Venus to its near solar tidelocked condition. Or both. (5) I have my doubts about the efficacy of underwater volcanos; too episodic. In any case, until artificial abiogenesis is actually demonstrated, we cannot begin to explore the range of conditions under which abiogenesis can occur with various expected times. (6) Nickel is required for current organisms with methane metabolisms; probably always so. Iron is a minor planet nutrient and essential for bacteria with an iron metabolism. Nickle-iron goes to the core during intial melting of a planet and does not ever come back up. So the initial enhancement of the mantle in both nickle and iron is important for various metabolisms, including photosynthetic ones. Can’t do this by just choosing a different generation of star; Ward & Brownlee have more on similar points.

    What does not seem to have happened yet is an adequate number of simulations of early solar system evolution to detrmine the probability of a proto-Luna in an L4 (or L5) position. I currently view the probability as low because 1/10 Terra mass is quite a bit to stay at L4 for long. This suggests that the impactor had to form quite rapidly, a low probability event.

    Somewhere there was a comment regarding ozone as a hyrogen protector. Fine, but note that without the oxygen catastrophy there would be no ozone. Hence photosynthesis had to come first and early life had to get along without ozone protection for 1+ billion years. Again, a possible race against time to avoid hydrogen escape, one which, according to a fairly recent article in Scientific American, Terra will eventually lose.

    Barton Paul Levenson // August 20, 2009 at 11:27 am — If we had oxygen isotope ratios for Venus and Mercury it might be possible to determine whether or not Mercury formed as a moon of Venus in a manner similar to Terra-Luna.

    In any case, careful projections of the future of the solar system suggest that Mercury is not stablized and may at any time either just wander out of the entire solar system or else settle into an orbit between Mars and the asteroid belt. Turns out that Venus and Terra-Luna are in some sort of mutually stabilizing resonance. [This from a conference paper I read several years ago.]

  • David B. Benson // August 20, 2009 at 11:28 pm

    Theia impact on proto-Terra with retrograde, high speed spin:

    The Moon’s Creation May Have Influenced the Way Earth Spins
    Earth could have spun much faster in the past
    http://news.softpedia.com/news/The-Moon-039-s-Creation-May-Have-Influenced-how-Earth-Spins-83869.shtml
    is suggestive and demonstrates that some additional study has been done on the Theia impactor.

  • David B. Benson // August 21, 2009 at 1:09 am

    Correcting an earlier comment of mine: “The relatively small range for the Earth is due to the stabilizing influence of the Moon, but it will not remain so. According to Ward, the orbit of the Moon (which is continuously increasing due to tidal effects) will have gone from the current 60 to approximately 66.5 Earth radii in about 1.5 billion years. Once this occurs, a resonance from planetary effects will follow, causing swings of the obliquity between 22° and 38°. Further, in approximately 2 billion years, when the Moon reaches a distance of 68 Earth radii, another resonance will cause even greater oscillations, between 27° and 60°. This would have extreme effects on climate.”
    from
    http://en.wikipedia.org/wiki/Axial_tilt

    Here is an interesting report about important prokaryotes:
    Research Reveals Major Insight Into Evolution Of Life On Earth
    http://www.sciencedaily.com/releases/2009/08/090819135436.htm
    with the implication it might have been early forms of clostridia with produced the end-Hadean banded iron formations.

  • David B. Benson // August 21, 2009 at 2:10 am

    Solar System Is Pretty Special, According To New Computer Simulation
    http://www.sciencedaily.com/releases/2008/08/080807144236.htm

    These simulations use constitutive laws for the gas dynamics, but still appears to be the most sophisticated to date. If this holds up to further analysis, it certainly supports my contention that abiogenesis is quite, quite rare in the cosmos.

  • Hank Roberts // August 21, 2009 at 3:03 am

    > CO2

    “Nevertheless …”

    http://resources.metapress.com/pdf-preview.axd?code=65u4473587280k16&size=largest

    http://adsabs.harvard.edu/abs/2008DPS….40.5406S

    laboratory experiments on EUV photodissociation of CO2 can be used to deduce what will be seen when spectra become available, at least in relation to that fraction of the emissions originating with photoabsorption. …. The results of experiments on the 12-14 eV photodissociation of CO2 at the Advanced Light Source (ALS) will be presented….This research was supported by the NASA Outer Planets program.

  • Timothy Chase // August 21, 2009 at 7:09 am

    Re David B. Benson

    I am going to have to put off responding at the moment. It is getting a little late and I have to leave early tomorrow — and I would prefer not to post a rushed response.

    Take care.

  • Barton Paul Levenson // August 21, 2009 at 9:39 am

    Mark:

    “Yes, I see it. It’s wrong. CO2 has no strong absorption bands in the ultraviolet,”

    And who said that CO2 had to have strong absorption bands?
    You.

    No, Mark. Not me. Radiation physics.

    Here again is what ***I*** said:
    “Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.”

    The higher energy photons won’t do any such damn thing if the molecule in question doesn’t absorb them. You really, really need to read a basic book on radiation physics. For this kind of thing, I can highly recommend Grant W. Petty’s “A First Course in Atmospheric Radiation” (2nd Ed. 2006).

    You seem to be creating your own reality and arguing it.

    No, I’m just somebody who’s been interested in planetary astronomy since 1973 and has a degree in physics.

  • Mark // August 21, 2009 at 10:26 am

    “No, Mark. Not me. Radiation physics.”

    I never said it either:

    Here again is what ***I*** said:
    “Timothy, the higher energy photons and charged particles Venus gets will readily split any chemical bond.”

    Note the “charged particles” bit?

    No, I don’t suppose you did with your nose in the air like that.

    “No, I’m just somebody who’s been interested in planetary astronomy since 1973 and has a degree in physics.”

    And I’ve done Physics with Astrophysics and got a degree.

    Colour me unimpressed with mere “I’ve been interested”….

  • Mark // August 21, 2009 at 10:29 am

    “In any case, careful projections of the future of the solar system suggest that Mercury is not stablized and may at any time either just wander out of the entire solar system or else settle into an orbit between Mars and the asteroid belt.”

    Correct, but that “any time” is “in several million years. Give or take several million…”.

    It’s also rather more likely to whizz right out of the solar system. If it takes that energy from a passing by of earth of venus then we’re in trouble too, since one or the other is going to go cometary on us…

  • Mark // August 21, 2009 at 10:34 am

    The smileys one is missing the bra-ket > <

    Because I LOATHE plain text going all ape-shit because someone doesn’t want to code their blog app (and the wordpress code is better than I’d do: I, however, would have avoided all the themability until AFTER I’d gotten the damn plain text working with > and other HTML-reserved-but-not-plain-text-reserved-printable characters).

    So I’ll use curly brackets. Substitute for angle brackets.

    ++++
    I really preferred the IRC “{grin}” or “{guffaw}” than that bloody awful :-) or :-P. But we’ve all gone HTML, so we can’t use brackets any more.
    ++++

    And amply demonstrated the last sentence there by being ripped out from a PLAIN TEXT entry panel because the blog engine doesn’t want to go to the difficulty of finding and changing the angle brackets.

  • Ray Ladbury // August 21, 2009 at 12:01 pm

    Mark, the fact is that CO2 is pretty stable against UV. What is more, it’s probably less vulnerable to dissociation via ionizing radiation than most gas molecules due to its chemical stability. We actually have a pretty good laboratory for what is stable in an atmosphere against solar wind in Mars, and it’s atmosphere is mostly CO2. I do not see that a pissing contest with Barton is in anyone’s interest.

  • Mark // August 21, 2009 at 3:21 pm

    “Mark, the fact is that CO2 is pretty stable against UV.”

    Yup, and the only one who has the idea that there was UV breaking up CO2 is BPL.

    I didn’t.

    I mentioned higher energy photons.
    Charged particles.

    UV is one small section of higher energy photons. And photons aren’t even the sole thing I mentioned.

  • David B. Benson // August 21, 2009 at 11:39 pm

    Gas disks to gas giants: Simulating the birth of planetary systems
    Authors: Edward W. Thommes, Soko Matsumura, Frederic A. Rasio
    http://arxiv.org/abs/0808.1439
    is the paper that the previously posted popular article is about. The paper appears in AAAS Science; it is quite readable as it stands and suggests that Solar-system-like stellar systems are probably in the distinct minority. I recommend this paper as readable, well done and possibly provocative. This collection of researchers, sometimes with others, continue to work, refining their model in papers for speciality audiences.

  • Hank Roberts // August 22, 2009 at 2:36 am

    > breaking up CO2
    nobody clicked the links I posted? Seriously, going around to the barn and counting the teeth is always better than arguing.

  • Barton Paul Levenson // August 22, 2009 at 10:40 am

    Mark:

    Yup, and the only one who has the idea that there was UV breaking up CO2 is BPL.
    I didn’t.
    I mentioned higher energy photons.
    Charged particles.

    Well, photons aren’t charged, Mark. If you’re only phrasing things carelessly here and really meant two different sources of energy, I was only talking about the first–though I did mention, in my first post on the subject, that the charged particles were not present in great amounts either.

    UV is one small section of higher energy photons. And photons aren’t even the sole thing I mentioned.

    UV is the major section of higher energy photons FROM THE SUN, which are the only ones that matter if you’re talking about photodissociation of planetary atmosphere gases from solar energy. Of the Solar constant, about 8% is UV and less than one millionth is X-rays or gamma rays. And CO2 has practically no absorption bands in the UV range.

  • Timothy Chase // August 25, 2009 at 6:59 pm

    Sorry it has taken me a little while to get back. As I stated earlier, I was finishing up a summer quarter — and things had gotten a little hectic.
    *
    David B. Benson wrote:

    Timothy Chase // August 20, 2009 at 5:36 am — Well, I seem to have pinched your nerve by simply linking to a ppt which, although with some flaws, reviews the evidence and some results. (1) Strictly speaking, I am an agnostic atheist and view myself as primarily a scientist; everything is contingent.

    Yes, the paper is quite flawed by scientific standards, but not necessarily so much by the semi-religious standards of the venue. And frankly I was a little surprised that you pointed to that particular slide show as “the best by far”, stating that it “argues my position better than I can,” when in my view at least the author is quite biased in his objectives, letting no alternative scenarios stand in his way of arguing the unlikeliness of any natural origin of life. However, I can see despite the fact that both you and the author argue that the conditions for the natural origin of life are rare, you were simply refering to the “glancing collision” that he could actually claim some expertise in.

    As I have said, I don’t have a problem with religion (per se), but I do have a problem with mixing science and religion — as is the case in “intelligent design theory” and its earlier incarnation of “scientific creationism” that died an untimely but no means early death in 1982. And as for myself, I am a Spinozist of the Quasi denomination. We have more members than you might think — but have never been all that organized.

    David B. Benson wrote:

    The only planet which we are sure abiogenesis occurred is Terra. We need to understand the preconditions for that abiogenesis before even conjecturing if it is possible with different geological histories.

    Actually I wouldn’t disagree to strongly with you on this point. We need some understanding of the preconditions, but the true is the whole, and as such I doubt that we will ever fully understand the preconditions for the origin of life. And I would likewise argue that one shouldn’t claim that bacterial abiogenesis is rare or “takes too long” without an understanding of the preconditions or process of abiogenesis itself.

    David B. Benson wrote:

    In any case, until artificial abiogenesis is actually demonstrated, we cannot begin to explore the range of conditions under which abiogenesis can occur with various expected times.

    Well, what many would argue is that various steps of and principles concerning abiogenesis have been demonstrated, including: the formation of nearly all the amino acids in quantities that many would take to be sufficient to get the process going, the prebiotic synthesis of activated ribonucleotides (including canonical pyramidines) the spontaneous formation of linear chains of RNA up to fifty nucleotides long in the presence of the mineral montmorillonite, the identification of RNA replicators of less than fifty nucleotides in length, the demonstration of a relaxed error threshold in the evolution of primitive RNA-based life towards the achievement of fully organic cells and the identification of the fact that the transition to DNA likely began* to take place prior to the achievement of fully organic cells. Moreover, we know that much of the chemistry that results in prebiotic, organic chemistry, e.g., the formation of acetate and ammonia, takes places under conditions resembling hydrothermal vents — with the appropriate temperatures, pressures and reactants, which would have made possible a plausible first metabolism.

    But given the very nature of the problem — where even the question of whether something qualifies as a form of life if it is not a form of cellular life or lacks a metabolism (e.g., viruses) and the likelihood that Darwinian selection was taking place among Earth’s first RNA and then DNA replicators prior to the formation of organic, biological cells, it would seem that by some definitions abiogenesis has already been demonstrated in the laboratories as far back as the early 1970s — and by other definitions might take centuries or millenia to perform — even if one assumes a rather large laboratory. So I believe this particular requirement isn’t all that reasonable — any more than it would be to argue that we can’t know what caused the transition from one paleoclimate to another unless we can replicate that in the laboratory as well. The transition from prebiotic chemistry to what we would generally consider life is something which took place in a series of steps and degrees, not in any single event to be replicated under laboratory conditions, and in my view at least it is a mistake of no small proportion to demand that it be otherwise.

    In any case, I don’t think there is actually that great of a difference in opinion between us. You argue at times that the origin of bacterial life would be rare, at others only the origin and subsequent evolution of such life prior to a runaway greenhouse effect would be rare — and I actually see no real evidence that such a runaway greenhouse effect will occur in the absence of high solar radiance, an ocean for water vapor and the sublimation of rock. But setting that aside, the differences between us aren’t that great. However, there is one other point which should be addressed: when you state, “I … view myself as primarily a scientist,” being someone who specializes in computer science (and who has had from what I am able to gather a fairly brilliant career in that specialty) does not make one particularly qualified to render judgments in the biological, climatological or astrophysical sciences, at least no more so than I myself. However, you have raised some interesting points, some of which I hope to follow up — as time permits. But at this point I have a number of items that I need to turn my attention to (including obligations to others and my own future), things which I likewise put off during the last week or so of school and not that much time until school starts again, so I may not be able to devote that much time to this discussion as I might like if you wish to continue it.

    * Jan P Erzberger, Melissa L Mott & James M Berger (2006) Structural basis for ATP-dependent DnaA assembly and replication-origin remodeling, Nature Structural & Molecular Biology – 13, 676 – 683

  • David B. Benson // August 25, 2009 at 9:58 pm

    Timothy Chase // August 25, 2009 at 6:59 pm — Thank you for the thoughtful reply. In this exchange I’ve learned to modify my position to

    abiogenesis followed by life survival for at least 4 billion years is rare.

    This is a Bayesian prior, if you will. It is modifyable in light of additional information.

    As a small note, viruses are but parasites, so cannot have been first. I appreciate the “metabolism first” idea but I’ll wait until artificial abiogenesis, whatever comes first, has been successfully demonstrated.

    The other matter I have learned something about is the rather spcial conditions needed to form the Solar System. Of course we don’t know whether or not a stellar system must be highly similar for abiogenesis, but I’ll opine that the formation of Terra is important.

    Since at this state of knowledge these matters can only be matters of opinion, unless something further comes up more closely related to Terra’s paleoclimate, probably we can gone far enough for now.

    With respect,
    David

  • Timothy Chase // August 26, 2009 at 6:25 am

    David B. Benson wrote:

    Solar System Is Pretty Special, According To New Computer Simulation
    http://www.sciencedaily.com/releases/2008/08/080807144236.htm

    These simulations use constitutive laws for the gas dynamics, but still appears to be the most sophisticated to date. If this holds up to further analysis, it certainly supports my contention that abiogenesis is quite, quite rare in the cosmos.

    You might like this:

    Gas disks to gas giants: Simulating the birth of planetary systems
    Edward W. Thommes, Soko Matsumura, Frederic A. Rasio
    Submitted on 11 Aug 2008
    Science 8 August 2008: Vol. 321. no. 5890, pp. 814 – 817
    http://arxiv.org/abs/0808.1439

    That is the tech article the Science Daily was about.

    They are looking at up to the first 500,000,000 years and 100 simulated solar systems. What they find is that solar systems with too much initial mass tend to become chaotic, ultimately stablizing with planets that have fairly eccentric orbits or solar systems with too little mass which tend to be empty.

    According to their analysis, the solar systems with near circular orbits similar to what we find in our own have to strike a balance of sorts between having too much mass and not enough. Porridge. Interestingly, it appears that it isn’t the Jupiter-sized planets you have to worry about.

    You might also be interested in the following 29 results, almost all of which appear to be by the same authors as the article you were pointing us to and on roughly the same subject:

    http://arxiv.org/find/astro-ph/1/au:+Thommes_E/0/1/0/all/0/1

    Three appear to be more recent. Anyway, found that and a few other items last week but didn’t have a chance to post them.

  • Mark // August 26, 2009 at 10:26 am

    “abiogenesis followed by life survival for at least 4 billion years is rare.”

    But we won’t be waiting for 4Billion years.

    And is there a need for 4 billion years to wait? After all, the earth was no Eden for 3 billion of those.

    “Since at this state of knowledge these matters can only be matters of opinion”

    Yup.

    You came late to that conclusion, but you did eventually get there.

  • Mark // August 26, 2009 at 10:29 am

    BPL: “Well, photons aren’t charged, Mark.”

    I know.

    But charged particles are.

    Aren’t they.

    And UV can kick out and ionise otherwise neutral diatoms making them

    a) move quickly
    b) charged

    And the binding energy of Carbon isn’t really all that high.

  • Timothy Chase // August 26, 2009 at 3:27 pm

    To varying degrees, anything that doesn’t strictly follow from the law of identity is to varying degrees a matter of opinion, but some opinions have a great deal more justification than others and empirical justification is cumulative.

  • Hank Roberts // August 26, 2009 at 6:24 pm

    http://www.skepticalscience.com/link_to_us.php

    Wonderful tool there, in case any one besides me had failed to notice it.

  • Timothy Chase // August 26, 2009 at 6:27 pm

    David B. Benson wrote:

    Here is an interesting report about important prokaryotes:

    Research Reveals Major Insight Into Evolution Of Life On Earth
    http://www.sciencedaily.com/releases/2009/08/090819135436.htm

    with the implication it might have been early forms of clostridia with produced the end-Hadean banded iron formations.

    This is the tech paper (abstract only):

    James A. Lake (20 August 2009) Evidence for an early prokaryotic endosymbiosis, Nature 460, 967-971
    http://www.nature.com/nature/journal/v460/n7258/abs/nature08183.html?lang=en

    Here are some other papers on symbiosis that may be of interest (all but one are full articles):

    Charles G. Kurland et al (12 November 1998) The genome sequence of Rickettsia prowazekii and the origin of mitochondria, Nature 396, 133-140
    http://www.nature.com/nature/journal/v396/n6707/pdf/396133a0.pdf

    William Martin et al (17 September 2002) Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastid phylogeny and thousands of cyanobacterial genes in the nucleus; PNAS vol. 99 no. 19 12246-12251
    http://www.pnas.org/content/99/19/12246.full.pdf+html

    N Cermakian, T M Ikeda, R Cedergren, and M W Gray (15 Feb 1996) Sequences homologous to yeast mitochondrial and bacteriophage T3 and T7 RNA polymerases are widespread throughout the eukaryotic lineage, Nucleic Acids Res.; 24(4): 648–654
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=145688

    Franck Dedeine et al (15 May 2001) Removing symbiotic Wolbachia bacteria specifically inhibits oogenesis in a parasitic wasp
    http://www.pnas.org/content/98/11/6247.full

    Elena Casacuberta and Mary-Lou Pardue (July 2002) Coevolution of the telomeric retrotransposons across Drosophila species, Genetics. 2002 July; 161(3): 1113–1124
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1462189

    Mary E. Rumpho et al. (May 2000) Solar-Powered Sea Slugs. Mollusc/Algal Chloroplast Symbiosis; Plant Physiology, Vol. 123, pp. 29–38
    http://www.plantphysiol.org/cgi/reprint/123/1/29.pdf

    Sidney K. Pierce et al (August 1999) Annual Viral Expression in a Sea Slug Population: Life Cycle Control and Symbiotic Chloroplast Maintenance, Biol. Bull. 197: 1-6
    http://www.biolbull.org/cgi/reprint/197/1/1.pdf

    Jennifer Lippincott-Schwartz et al (21 July 2009) A hyperfused mitochondrial state achieved at G1–S regulates cyclin E buildup and entry into S phase,PNAS vol. 106 no. 29 11960-11965
    http://www.pnas.org/content/106/29/11960.full

    The X-endosymbionts are unidentified, gram negative, rod-shaped bacteria that spontaneously infected a strain of Amoeba proteus as harmful parasites in 1966 (16), but that since have become required components of the host cells (xD amoebae) (13, 15).

    Jang H. Han and Kwang W. Jeon (March 1980) Isolation and Partial Characterization of Two Plasmid Deoxyribonucleic Acids from Endosymbiotic Bacteria of Amoeba proteus, Journal of Bacteriology, Vol 141 No 3, pp. 1466-1469
    http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=293862&blobtype=pdf

    Retroviruses and Placental Mammals:

    Thomas E. Spencer et al (15 Sep 2006) Endogenous retroviruses regulate periimplantation placental growth and differentiation, PNAS vol. 103 no. 39 14390-14395
    http://www.pnas.org/content/103/39/14390.full

    Thierry Heidmann el al (21 July 2009) Syncytin-A knockout mice demonstrate the critical role in placentation of a fusogenic, endogenous retrovirus-derived, envelope gene, PNAS vol. 106 no. 29 12127-1213
    http://www.pnas.org/content/106/29/12127

    Joachim Denner et al (June 2006) Transspecies Transmission of the Endogenous Koala Retrovirus, Journal of Virology, p. 5651-5654, Vol. 80, No. 11
    http://jvi.asm.org/cgi/content/full/80/11/5651

    Jonathan P Stoye (2006) Koala retrovirus: a genome invasion in real time, Genome Biol. 7(11): 241
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1794577

    (30 Oct 2007) Maribeth V. Eiden Changes in viral protein function that accompany retroviral endogenization, PNAS Vol 104 No 44, pp 17506-17511
    http://www.pnas.org/content/104/44/17506.full

  • Timothy Chase // August 26, 2009 at 6:31 pm

    PS

    The above are all instances of endosymbiosis.

  • Deech56 // August 26, 2009 at 7:23 pm

    New proxy record: Oppo, et al.. Despite the authors’ caveats, I am sure that this will be spun to “MWP warmer than current temperatures.”

    • KenM // August 26, 2009 at 8:14 pm

      I’ve read elsewhere that there’s some doubt as to whether the MWP (and LIA for that matter) were global phenomenon. What does this new proxy mean for that hypothesis?

  • Hank Roberts // August 26, 2009 at 9:44 pm

    KenM, what “elsewhere” are you relying on for the notion there is merely “some doubt” about this? “Much evidence to the contrary” would be a better description.

    Want a good summary with slides? Watch and listen to this lecture from one of the National Academy of Sciences experts, one of those who wrote the NAS report covering the questions raised:

    http://geotest.tamu.edu/userfiles/216/NorthH264.mp4

    • KenM // August 27, 2009 at 5:07 am

      Most recently the wikipedia entry on MWP, which incidentally mentions some proxy data from New Zealand supporting the view that the LIA was global. “Some doubt” as a choice of words was mostly arbitrary – just acknowledging that the science is apparently not settled on the subject. This new paper appears to make the “regional” argument stretch a little (geographically) at least. I’ll check out the link, thanks – was the presenter aware of this new proxy?

  • Timothy Chase // August 26, 2009 at 10:00 pm

    Deech56, KenM–

    An earlier slide presentation from about a month ago based on the same data I believe…

    Coherence between the Asian monsoon and
    Indonesian hydrology during the past two millennia
    Jessica E. Tierney
    PAGES YSM Conference : 7 July 2009
    Co-authors: Delia W. Oppo, James M. Russell,
    Braddock K. Linsley, Yair Rosenthal
    http://www.pages.unibe.ch/products/osmysmtalks09/YSM09_OralF_JessicaTierney.pdf

    I may be wrong, but this looks like one proxy from one location. An important location apparently, but a shift in sea currents could make it rather unrepresentative of global trends. However, if it were in fact representative, within their error bars at least (which will generally be greater the fewer the proxies that are used), we would be roughly tied with the MWP.

  • Gavin's Pussycat // August 26, 2009 at 10:41 pm

    Deech56:

    > Makassar Strait, Indonesia

    One site. Perhaps representative for a larger area, who knows

    > Reconstructed SST was, however, within error
    > of modern values from about ad 1000 to ad 1250, towards the end of the
    > Medieval Warm Period.

    “Within error”. Not higher. Certainly not significantly higher. Just not provably lower.

    Hmmm, wonder how big the error was?

    But Deech… yes.

  • Hank Roberts // August 27, 2009 at 4:10 am

    Hat tip to poster ‘Larchitect’ over at
    http://www.newscientist.com/blogs/shortsharpscience/2009/08/us-business-lobby-demands-scop.html#nbicomments

    for this:

    http://www.nature.com/nature/journal/v410/n6826/abs/410355a0.html

    Letter: Nature 410, 355-357 (15 March 2001) | doi:10.1038/35066553; Received 17 May 2000; Accepted 15 January 2001

    Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997

    “… Changes in the Earth’s greenhouse effect can be detected from variations in the spectrum of outgoing longwave radiation8, 9, 10, which is a measure of how the Earth cools to space and carries the imprint of the gases that are responsible for the greenhouse effect11, 12, 13. Here we analyse the difference between the spectra of the outgoing longwave radiation of the Earth as measured by orbiting spacecraft in 1970 and 1997. We find differences in the spectra that point to long-term changes in atmospheric CH4, CO2 and O3 as well as CFC-11 and CFC-12. Our results provide direct experimental evidence for a significant increase in the Earth’s greenhouse effect that is consistent with concerns over radiative forcing of climate.”

    Cited by:

    http://www.nature.com/cited/cited.html?doi=10.1038/35066553

  • Hank Roberts // August 27, 2009 at 2:56 pm

    KenM // August 27, 2009 at 5:07 am writes:

    > Most recently the wikipedia entry on MWP,
    > which incidentally mentions some proxy data
    > from New Zealand … This new paper …
    >… was the presenter aware of this new proxy?

    Ken, see the little blue numbers in square brackets? One of those follows the only mention of New Zealand on that Wikipedia page. Click on it.

    Who told you that was a _new_ paper? Why do you believe whoever told you, and repeat what they told you? Why do you trust your source?

    Try clicking the little blue number next to the Wikipedia text, and tell us what you think.

    • KenM // August 27, 2009 at 3:49 pm

      Hi Hank, I think you misunderstood due to my liberal use of pronouns.
      “new proxy” = the paper deech refers to. I’m assuming it’s new because the pub date is 8/27/09.
      I only mentioned New Zealand as evidence for “some doubt” (btw I misstated it “LIA” – the wiki is actually referring to MWP) I’m also assuming the new proxy (again I’m talking about Deech’s link – not the New Zealand reference in wikipedia) will also contribute to the “MWP was strictly a NH Atlantic phenomenon” doubt.
      As long as we’re talking about New Zealand – has the 1979 paper been corrected somehow? Again I’m assuming the answer is “no” because there’s no cited criticism in the wiki.

      I enjoyed the presentation you linked. The section on how the data is gathered was especially fascinating.

  • Mark // August 27, 2009 at 3:05 pm

    But that would be devastating to his case, Hank!

  • Hank Roberts // August 27, 2009 at 7:38 pm

    For questions about Wikipedia, try asking at Wikipedia or ask your reference librarian for help.

    In other news (subscription may be required):

    http://www.sciencenews.org/view/generic/id/46776/title/Nitrous_oxide_fingered_as_monster_ozone_slayer

    “… Owing to its roughly 100-year survival time in the atmosphere (a lifespan comparable to CFCs) and the huge quantities released each year, N2O stands poised to become a potent player in the thinning of global stratospheric ozone. Indeed, “We found that if you look ahead, N2O will remain the largest ozone-depleting emissions for the rest of the century,” notes team leader A.R. Ravishankara.

    A paper describing the new analyses was posted online today in Science….”

    “N2O is now a bigger threat to future stratospheric ozone destruction than are CFCs. And if N2O-emissions don’t diminish substantially, Ravishankara says, within a century they could eventually slay 40 percent as much stratospheric ozone each year as CFCs did at their peak.

    Reporters asked the NOAA team what can and should be done, but the scientists simply argued that finding answers was the responsibility of policymakers. However, Ravishankara observed that because most N2O releases are so diffuse, limiting them will prove much more challenging than simply mandating controls on tailpipes or smokestacks.

    Yet success would yield a doubly whammy, notes coauthor John Daniel. The reason: N2O is also a greenhouse gas.”

  • David B. Benson // August 27, 2009 at 10:47 pm

    Mark // August 26, 2009 at 10:26 am — I stated that at the beginning of that subtopic.

    KenM // August 27, 2009 at 3:49 pm — MWP Not So Hot
    http://www.sciencedaily.com/releases/2003/10/031020055353.htm
    and not global; Patagonia and all points south of there did not participate. LIA, on the other hand, appears to have been global.

  • Timothy Chase // August 28, 2009 at 12:06 am

    KenM wrote:

    “new proxy” = the paper deech refers to. I’m assuming it’s new because the pub date is 8/27/09.

    I am not an expert by any means, but in my view the new proxy could at least potentially be important — at least as one more chronological series data points. In the presentation that Hank pointed us to, the presenter made the point that we actually have very few proxies for the Southern Hemisphere. The map showed that they were particularly sparse if one went as far back as the Medieval Warm Period. But in the Northern Hemisphere at least, typically when they speak of proxies they are speaking of entire networks of the same kind of proxy and then different kinds of proxies going back. The again, what the new paper at least is talking about isn’t really that southern. It is more equatorial, being only 4°C south of the equator.

    But it is at least at a fairly special location. Roughly dead center of Indo-Pacific Warm Pool — which according to the slide presentation I linked up to is “the largest zone of deep atmospheric convection on Earth.” But it doesn’t really appear that far off the coast, so I am not sure how representative that particular location is of the surrounding, deepr ocean, or more importantly, how representative it was of the Indo-Pacific Warm Pool nearly a millenia ago.

    In this case we are speaking of the ratio of isotopes, specifically hydrogen to deuterium. In what Hank linked us to the presenter pointed out that the ratio of different isotopes of oxygen was a very good proxy in the northern latitudes but that they became a poor proxy in the equatorial regions. Not sure how well that would apply to hydrogen vs. deuterium.

    But given its location at least, it would seem that one might claim that this particular location is more representative of average global temperature, particularly on the decadal scale (insofar as it is presumably more sensative to ocean temperatures) — than a proxy at nearly any other location, particularly since most of the proxies we have are land-based, and to the extent that they are inland are less subject to the stabilizing influences of an ocean that has greater thermal inertia vs. the vaguaries of an atmosphere that has a much shorter memory. But that would be for one location. If you have a large network then I would put more trust in the law of large numbers.

    Now originally and particularly in the second of the two papers 1998-9, the hockey stick showed little more than a blip for the Medieval Warm Period. More recently (that is, as of 2008) the hockey stick by Mann et al shows a much more pronounced Medieval Warm Period. In terms of the presentation that Hank linked us to, the presenter made a point of the fact that different locations experienced their warm periods at different times. But what context was he operating from? Early to mid 2000s? 2008? I am not sure.

    Well, he did mention the spaghetti graph — that consisted of the various hockey stick diagrams by different teams of researchers. So I would presume that this is what he was going off of. In which case the Medieval Warm Period would have been more than a blip but not quite as pronounced as the Mann et al 2008. And the other major difference between the late (2008) and early (1998-9) Mann et al studies? The 1998-9 were pioneering. The 2008 is currently the best we have to offer.

    So when you stated that there’s some doubt as to whether the Medieval Warm Period was a global phenomenon, that would certainly apply in the context of the Mann et al 1998 or later. But whether it is descriptive of the current mainstream view (to the extent that there is one — which in this case would still most likely consist of the Mann et al 2008) is considerably more dicey.

    But regarding the Little Ice Age? Actually the proxies are well aligned on that one — according to the presentation that Hank pointed us to. And consequently it would appear that there really hasn’t been much doubt on the global nature of the Little Ice Age, at least not within the past decade or so. But of course when you refered to New Zealand, that was actually in the context of the Medieval Warm Period, not the Little Ice Age.
    *
    However, all of the above pretty much focuses on whether there was a Medieval Warm Period or Little Ice Age — which was afterall what you were focusing on. But in terms of the recent study itself going off of hydrogen to deutrium just off of the Sulawesi coast in Indonesia (Oppo et al 2009), the question that people will be focusing on is whether the global temperature during the Medieval Warm Period ever rose to a point that was comparable to the late 20th Century. Mann et al. 2008 has the Medieval Warm Period and the mid-20th statistically tied, but shows the late-20th Century as going beyond anything that has been experienced within the past 1800 years — and probably much further back than that.

    But the current study? In terms of their own uncertainty bars which I believe they acknowledge to be fairly large they show the late 20th Century and the peak of the Medieval Warm Period as having almost exactly the same temperature. Not with the Medieval Warm Period being warmer, but only tied — with the two temperatures being far closer than what their study claims as statistically significant simply within the context of that study itself.

    And the uncertainty bars for one proxy from only one location have to be much wider than what one gets from an array of proxies spread out over a much larger area. And granted, the array is getting pretty sparse by 1000 AD, but the period for which the Oppo et al 2009 is showing a peak is roughly 1200 AD — when things were much less sparse.

    But then there is the Roman Warm Period. They would seem to be showing the Roman Warm Period as statistically tied with both the Medieval Warm Period and the late 20th Century. But no one else is showing anything like that. Rather, the Roman Warm Period is generally viewed as considerably cooler, warmer than the Medieval Warm Period according to some proxies, but likely at least 0.4°C below the late 20th Century.

    Anyway, I hope this helps.

  • David B. Benson // August 28, 2009 at 12:47 am

    Timothy Chase —- Yes, I have read the Thommes et al. paper twice now. (I had linked to it here in an earlier comment.) I’ve also been through some related studies by that research group as well as other authors. All suggest that stellar systems resembling the Solar System are likely to be rare. Unfortunately, there are so far no estimates for the probability.

    More directly on abiogenesis, the propoal in

    http://www.biology-direct.com/content/4/1/26
    (On the origin of life in the Zinc world: 1. Photosynthesizing, porous
    edifices built of hydrothermally precipitated zinc sulfide as cradles of
    life on Earth)

    http://www.biology-direct.com/content/4/1/27
    (On the origin of life in the Zinc world. 2. Validation of the hypothesis
    on the photosynthesizing zinc sulfide edifices as cradles of life on
    Earth)

    is of interest since it requires a zinc enriched mantle (which Terra has) and a UV transparent early atmosphere with at least 10 bar CO2. Yikes!

    For a good, short read on endosymbiosis, see “Russian Dolls”, recent on Carl Zimmer’s blog, The Loom.

  • Deech56 // August 28, 2009 at 1:09 am

    Tim, thanks for the summary of the paper. I have been trying to add a few things from my reading of the paper, but end up running out of time and being concerned about my own level of ignorance. The error they report is large – IIRC about 0.2 degrees for SST and 0.2 % delta O-18 (which appears to correspond to about 0.4 degrees).

    To my mind, this could be useful when included with the other proxies. It’s always good to have more data.

  • Hank Roberts // August 28, 2009 at 1:45 am

    uh, oh:
    http://www.reuters.com/article/scienceNews/idUSTRE57P08Z20090826

    “… LOS ANGELES (Reuters) – Bouts of extreme muggy heat lasting for days, once rare in California, are becoming more frequent and intense due to ocean patterns altered by climate change, scientists said in a study released on Tuesday.

    Research meteorologists at the University of California’s Scripps Institution of Oceanography reached the conclusion ….”

  • Timothy Chase // August 28, 2009 at 4:36 am

    David B. Benson wrote:

    Timothy Chase —- Yes, I have read the Thommes et al. paper twice now. (I had linked to it here in an earlier comment.) I’ve also been through some related studies by that research group as well as other authors. All suggest that stellar systems resembling the Solar System are likely to be rare. Unfortunately, there are so far no estimates for the probability.

    Well, I think Thommes et al are right — but judging from the tech articles themselves, stellar systems like ours (in terms of the near circularity of their orbits at least) aren’t necessarily that rare — insofar as they were dealing with only about a hundred simulated systems and there were systems similar enough to them that they could arrive at some generalizations regarding those systems. But then you have to ask whether there is a planet in a habitable zone, how stable the climate system is and so on, so I certainly expect multicellular life to be quite rare. Then again, I’ve heard that if you are one in a million in New York City then there are eight people just like you in town.
    *
    David B. Benson wrote:

    More directly on abiogenesis, the propoal in

    http://www.biology-direct.com/content/4/1/26
    (On the origin of life in the Zinc world: 1. Photosynthesizing, porous
    edifices built of hydrothermally precipitated zinc sulfide as cradles of
    life on Earth)…

    I will have to read the papers by Armen Y Mulkidjanian. Here is another which I should get to:

    The not so universal tree of life or the place of viruses in the living world (abstract only)
    Harald Brüssow
    Phil. Trans. R. Soc. B 12 August 2009 vol. 364 no. 1527 2263-2274
    http://rstb.royalsocietypublishing.org/content/364/1527/2263.abstract

    Someone sent me a copy a couple weeks ago — so I should get to it, and feel somewhat obligated to read it first — even before I really get into “The RNA World” which arrived earlier this week.
    *
    David B. Benson wrote:

    For a good, short read on endosymbiosis, see “Russian Dolls”, recent on Carl Zimmer’s blog, The Loom.

    Carl Zimmer loves parasites — has even written a book on them:

    Parasite Rex : Inside the Bizarre World of Nature’s Most Dangerous Creatures (Paperback)
    by Carl Zimmer
    http://www.amazon.com/gp/product/074320011X

    … and has actually done a fair number of essays on some of the very same topics in symbiosis that I brought up above.

    For example, the role of endogenous retroviruses in pregnancy:

    And most remarkble, sometimes genes from viruses become useful to their hosts. It appears that virus genes have become vital for the development of primate placentas, and to carry out other essential tasks. While these genes retain distinctive sequences seen only in retroviruses, they show signs of having been preserved by natural selection, even as the viral genes that surround them have mutated into uselessness.

    The Sixty-Million-Year Virus
    March 13th, 2006
    by Carl Zimmer
    http://blogs.discovermagazine.com/loom/2006/03/13/the-sixty-million-year-virus/

    Of course it appears that they play just this sort role in the pregnancy of all placental mammals. For example, here are sheep and mice:

    Thomas E. Spencer et al (15 Sep 2006) Endogenous retroviruses regulate periimplantation placental growth and differentiation, PNAS vol. 103 no. 39 14390-14395
    http://www.pnas.org/content/103/39/14390.full

    Thierry Heidmann el al (21 July 2009) Syncytin-A knockout mice demonstrate the critical role in placentation of a fusogenic, endogenous retrovirus-derived, envelope gene, PNAS vol. 106 no. 29 12127-1213
    http://www.pnas.org/content/106/29/12127

    Frank Ryan (who I first learned about this from — and who is a personal acquaintance of Lynn Margulis, who championed endosymbiosis) has mentioned, however, that the placentas of different mammalian species are oftentimes quite different — and these differences appear to be a function of the retroviruses that are responsible for the creation of a barrier to the mother’s immune system. Evidently as new retroviruses undergo a process of endogenization they will often push-out the established retroviruses and take over the various roles in the placenta — and I would presume elsewhere in embryonic development.

    Here is an earlier, quite readable paper by Frank Ryan on endogenous retroviruses which explores the topic in more detail:

    Human endogenous retroviruses in health and disease: a symbiotic perspective (Open Access)
    J R Soc Med 2004;97:560-565
    http://jrsm.rsmjournals.com/cgi/reprint/97/12/560

    That is what got me interested in retroelements and the RNA world.

    Incidentally, Carl Zimmer recently brought up the theory by Lake on the origin of the double-membraned bacteria that gave rise to cyanobacteria that you drew our attention to:

    We are, fundamentally, a fusion. As I wrote in my essay for Science on the origin of eukaryotes, there’s now a wealth of evidence that our cells evolved from the combination of two different microbes….

    Plants, for example, descend from algae that engulfed a species of photosynthesizing bacteria. Many protozoans have swallowed up photosynthetic partners as well….

    Maybe a lot of today’s prokaryotes are also the result of an ancient merger. The idea comes from James Lake of the University of California, Los Angeles, a veteran researcher on the early history of life. In my essay, I describe how Lake first proposed in the early 1980s that the host cell that gave rise to eukaryotes belonged to a lineage of prokaryotes he dubbed eocytes. Now, a quarter of a century later, new studies on genomes are strongly supporting his eocyte hypothesis. In today’s issue of Nature, Lake questions whether we may be too quick to assume that only eukaryotes are the result of fusion.

    Microbes Within Microbes Within Microbes
    AUGUST 20, 2009
    Posted by Carl Zimmer
    http://blogs.sciencemag.org/origins/2009/08/microbes-within-microbes-withi.html

    He has also brought up the bacterial origin of mitochondria and the role of the bacteriophage that contributed genes for transcribing mitochondrial DNA here:

    The story does not stop here, though. Jonathan Filee and Patrick Forterre, two French biologists, have a paper in press in Trends in Microbiology reporting on some surprising results from their new studies of mitochondrial DNA. Some of the surviving genes in mitochondria produce enzymes whose job it is to build new mitochondrial DNA, as well as RNA, a single-stranded version of DNA that acts as a genetic messenger among other jobs. Unlike the rest of the genes in mitochondria, these DNA and RNA-building genes don’t resemble the corresponding genes of related bacteria. They are genes from viruses.

    Part Human, Part Virus
    SEPTEMBER 15, 2005
    Posted by Carl Zimmer
    http://www.corante.com/loom/archives/2005/09/15/part_human_part_virus.php

    … which I mentioned above here:

    Charles G. Kurland et al (12 November 1998) The genome sequence of Rickettsia prowazekii and the origin of mitochondria, Nature 396, 133-140
    http://www.nature.com/nature/journal/v396/n6707/pdf/396133a0.pdf

    N Cermakian, T M Ikeda, R Cedergren, and M W Gray (15 Feb 1996) Sequences homologous to yeast mitochondrial and bacteriophage T3 and T7 RNA polymerases are widespread throughout the eukaryotic lineage, Nucleic Acids Res.; 24(4): 648–654
    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=145688

    And he has brought up the solar-powered sea slug as well as it viral symbiote here:

    We are doing high-throughput sequencing now on the sea slug transcriptome [the genes expressed in specific cells] and hopefully soon, the genome, so we should learn a lot more about which genes are there. I will also mention that we frequently/always? find a virus in the sea slug that really takes off as the sea slugs age. We believe it might be a retro-virus, but the support is not strong at this time. It’s possible the DNA is moving via a viral vector through the blood to the germ line.

    The Further Adventures of the Emerald Green Sea Slug
    November 18th, 2008
    Posted by Carl Zimmer
    http://blogs.discovermagazine.com/loom/2008/11/18/the-further-adventures-of-the-emerald-green-sea-slug/

    … which I pointed us to articles on here:

    Mary E. Rumpho et al. (May 2000) Solar-Powered Sea Slugs. Mollusc/Algal Chloroplast Symbiosis; Plant Physiology, Vol. 123, pp. 29–38
    http://www.plantphysiol.org/cgi/reprint/123/1/29.pdf

    Sidney K. Pierce et al (August 1999) Annual Viral Expression in a Sea Slug Population: Life Cycle Control and Symbiotic Chloroplast Maintenance, Biol. Bull. 197: 1-6
    http://www.biolbull.org/cgi/reprint/197/1/1.pdf

    … and that, I believe, is just scratching the surface. I haven’t gotten a copy of “Parasite Rex” as of yet, but I will have to.

  • Gavin's Pussycat // August 28, 2009 at 4:41 am

    > To my mind, this could be useful when included with the other proxies.
    > It’s always good to have more data.

    Depends… the big problem with the proxies is their geographical distribution. There’s a strong NH, extra-tropical, land bias. Adding more of the same doesn’t help and may actually be a bad idea. This particular proxy however looks indeed like being valuable in that sense.

  • Mark // August 28, 2009 at 9:56 am

    “I stated that at the beginning of that subtopic.”

    DB, no. You didn’t.

    You may have intended that to be read but it was nowhere near as clear as you think if it were so.

  • Deech56 // August 28, 2009 at 12:27 pm

    I was interested in the claim that these tropical SSTs represent global trends and found this in the supplementary information:

    In order to evaluate how well Indonesian SSTs have tracked global mean SSTs from AD 1856-1991 on multi-decadal and longer time scales, we correlated a 40-year averaged global mean annual SST index (30°S-60°N) to 40-year averaged SSTs throughout the world’s oceans 45(Supp. Fig. 4). The correlation analysis suggests that SST in our study area is strongly correlated to global SSTs (r>0.8) on this time scale.

    How well Indonesian SST tracks multi-decadal land temperatures depends on which of two historical SST reconstructions 8,45 is more accurate (Supp. Fig. 5). However, the increase of mean annual SST since AD 1900 in both reconstructions is similar to the rise of NH and global land temperature since AD 1900 46.The greater down-core amplitude of reconstructed Indonesian SST variations than reconstructed NH surface air temperature variations (Fig. 3a), therefore, may be related to changes in G. ruber seasonality.

  • Deech56 // August 28, 2009 at 12:32 pm

    Added: If possible, more locations would be better, IMHO.

  • Mark // August 28, 2009 at 1:32 pm

    Problem here is that it is one case where you really should start out with “correlation is not causation”.

    It may be hidden in quotes you didn’t bring forth, but what you’ve presented shows only correlation.

    Nothing about the causation that explains it.

    It is the causation that gives you the scientific testability. A correlation will ALWAYS work over the period correlated over. But a causation of that correlation can show when they are significantly divergent.

    Like, for example, the GCR causation. Fails because the correlation needing a weeks delay doesn’t work. But the data still correlates. What breaks it is the need for the delay for the causation to work.

  • Hank Roberts // August 28, 2009 at 6:17 pm

    http://www.nasa.gov/topics/earth/features/climate_computing.html

    “… In August, Goddard added 4,128 new-generation Intel “Nehalem” processors to its Discover high-end computing system. … will host NASA’s modeling contributions to the Intergovernmental Panel on Climate Change (IPCC)…. Goddard will install another 4,128 Nehalem processors in the fall, bringing Discover to 15,160 processors….”

  • Hank Roberts // August 28, 2009 at 6:41 pm

    http://johnquiggin.com/index.php/archives/2009/08/26/two-degrees-of-warming/

    “… The big impacts of climate change will be on agricultural production and natural environments and the relevant experts are ag scientists/economists and ecologists. The views of climate scientists like James Hansen, while very important in projecting the climatic effects of CO2 emissions, have no particular standing when it comes to assessing the damage associated with any particular climatic change.

    As regards the ag economics, I am an expert, and am therefore happy to explain my position and discuss it with readers. I will add some links later, but for the moment Ill ask you to take statements of fact on trust that Ive done the work to verify them

    What matters for agriculture is not so much the ultimate change in average temperature and rainfall, but the pace of change….”

    • Sekerob // August 28, 2009 at 7:47 pm

      Hank, by coincidence there was a news item of a statement by the head of the WMO on the troubles that weather forecasting is in since the long history is becoming less and less valid as a reference to make predictions for short and longer term v.v e.g. sowing.

      **World Meteorological Organization

      The head of the World Meteorological Organization (WMO), Michel Jarraud, says that, because of climate change, historical weather data is no longer a good indicator of trends to come and a good guide for decision-making.

      Jarraud said, in an interview with UN radio, that many socio-economic sectors are highly dependent on climate conditions to make decisions on the long-term nature of projects. He noted that it was important that these decisions be made on the basis of the best possible scientific information. Jarraud added that the goal of WMO’s World Climate Conference, next week in Geneva, is to link scientists and decision-makers.

      As you know, the Secretary-General will be in Geneva for the opening of the High-Level Segment of this conference on Thursday, 3 September.

  • Timothy Chase // August 28, 2009 at 9:22 pm

    Sekerob wrote:

    Hank, by coincidence there was a news item of a statement by the head of the WMO on the troubles that weather forecasting is in since the long history is becoming less and less valid as a reference to make predictions for short and longer term v.v e.g. sowing.

    A little dusty, perhaps, but for something else along much the same lines — which coincidentally I ran across again yesterday:

    David R. Easterling (22 Sept 2000) Climate Extremes: Observations, Modeling, and Impacts, Science, Vol. 289. no. 5487, pp. 2068 – 2074
    http://www.biosci.utexas.edu/ib/faculty/parmesan/classes/Eastl_Ntr_00.pdf

  • Hank Roberts // August 28, 2009 at 9:47 pm

    http://lowbagger.org/forestsfall.html

    “A primer and field guide to repeated disaster in the logging, lending, homebuilding, and real estate industries ….
    … this basic script has repeatedly dominated the economic stage, in one country after another. Trouble is, the commonplace disconnect of finance, construction, home, and forest has repeatedly put them all at risk, in shared spectacles where the forests fall first, and the banks fall just later enough to make the connection from forest to finance extremely difficult for the casual observer …

    … four seemingly stand-alone industries – lending, logging, construction, and real estate – are tightly united along a common stream of money. This integrated perspective can help many interested parties get a more realistic grasp of how the game is really played. For example, it makes clear that the forest conservation community and environmental journalists must look beyond the logging industry alone when attempting to account for irrationally exuberant levels of logging. This more integrated form of analysis should also be helpful in explaining the how and why of logging taken to such extreme that it has become one of the major contributors to a dangerously changing climate. …”

  • Timothy Chase // August 28, 2009 at 9:57 pm

    Sekerob, I found this on Reuters:

    Climate change has made history an inaccurate guide for farmers as well as energy investors who must rely on probabilities and scenarios to make decisions, the head of a United Nations agency said on Wednesday….

    History can no longer guide farmers, investors-U.N.
    Wed Aug 26, 2009 6:59am EDT
    By Laura MacInnis
    http://www.reuters.com/article/latestCrisis/idUSLQ96330

    However, the reporter points out that he is French. I believe this means that it is something we may want to take into consideration.

  • Hank Roberts // August 29, 2009 at 5:10 pm

    http://www.agu.org/pubs/crossref/2009/2009GL039516.shtml

    Trend evaluation in records with long-term memory: Application to global warming
    Trend evaluation in records with long-term memory: Application to global warming

  • Hank Roberts // August 29, 2009 at 5:11 pm

    PS, Tom started this particular thread with a mention of Lindzen’s ‘in press’ paper. That’s out this week too:
    http://www.agu.org/pubs/crossref/2009/2009GL039628.shtml

  • tamino // August 31, 2009 at 9:01 pm

    Please move discussion to the new open thread.

  • Like gas stations in rural Texas after 10 pm, comments are closed.