Open Mind

Shocking … uh … Surprising … um … Notable … well … Rather Ordinary News from Mauna Loa

April 8, 2008 · 87 Comments

Preliminary CO2 data for March of this year are available from the Muana Loa Atmospheric Observatory. The data indicate that CO2 concentration rose slightly from February to March, but not by as much as it usually does, so the seasonally adjusted value actually dropped from February to March:


The monthly values are plotted in red, the seasonally adjusted values in black. Some have made a big deal out of the fact that last month shows a decline in the seasonally adjusted value. Is it really unusual?

This graph only covers a few years; we can get a little more perspective by looking at all of the Mauna Loa data. I’ll reverse the colors, plotting monthly data in black, the seasonally adjusted values in red:

We can also look at the seasonally adjusted data in isolation:

From this, the most recent month doesn’t seem unusual. But is the most recent change unusual? I computed the monthly change in the seasonally adjusted value, i.e., the difference between each month’s value and the previous month’s value. Here’s the result, with the most recent month circled:

It’s quite clear that last month’s drop in seasonally adjusted CO2 concentration isn’t unusual at all. Bigger drops have happened before, as recently as 2004. And while last month’s change is definitely on the low side of normal, it’s also definitely on the low side of normal.

The real story from the Mauna Loa CO2 record is the long-term growth rate. I smoothed the seasonally adjusted data using a Savitsky-Golay filter, which enables one to compute not just the smoothed value, but the rate of change of the smoothed data directly. Here’s the smoothed (long-term) growth rate of CO2 concentration according to Mauna Loa data:

CO2 concentration has consistently risen since accurate measurements began. The rise has certainly not been linear; if it were, then the growth rate would be reasonably constant. But the growth rate itself has increased over the years, demonstrating a nonlinear increase in CO2. In fact, the growth rate now is on the order of 4 times as large as it was when Mauna Loa measurements began in the late 1950s.

Yet some are making a big deal out of a single month’s drop in seasonally adjusted CO2 concentration, one which turns out not to be at all unusual. Some have made a big deal of the fact that CO2 concentration is rising linearly while emissions are increasing — when in fact the rise is most certainly not linear. It’s really just an embarrassment to those who don’t know how to make sense out of data.

Categories: Global Warming · climate change
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87 responses so far ↓

  • kim // April 8, 2008 at 2:48 pm

    It’s that figure on the ‘low side of normal’ combined with slightly dropping ocean temperatures that makes it interesting. Is is more CO2 going into solution? Too soon to tell.
    =================================

    [Response: There's a well-known relationship between weather changes and CO2, with a time lag of several months, which appears to be due to the impact of weather changes on plant growth. For some realistic research about models of the carbon cycle, see this.]

  • kim // April 8, 2008 at 2:50 pm

    Also, is the intra-annual variation from increased uptake in the Northern Hemisphere summer biosphere or the Southern Hemisphere cooler winter waters. There seems to be controversy over this point.
    ============================

    [Response: No, there's no controversy at all. There's just ludicrous speculation by denialists in an embarrassing attempt to discredit the antrhopogenic origin of CO2 increase.]

  • Ian // April 8, 2008 at 2:59 pm

    Many people seem to be looking at the NOAA graph and thinking that there’s actually a drop in the CO2 ppm for Feb. It’s a bit of a replay of the “temp anomaly vs. raw temp” mistake from earlier this year.

  • JohnPaul // April 8, 2008 at 3:05 pm

    Since denialists don’t like the word denialist, and the word skeptic doesn’t really apply, here’s a suggestion for the right word to describe people in denial about global warming:

    [edit]

    [Response: Not very flattering. But it wasn't easy to stop laughing.]

  • kim // April 8, 2008 at 3:06 pm

    No, that business of dissolving in the Southern Oceans speaks to the intra-annual variation, not to the cause of the long term trend. Don’t try to confuse me; I do well enough on my own.
    ================================

  • kim // April 8, 2008 at 3:12 pm

    How come you didn’t post my follow-up question about biosphere decaying? It was not a bad question. You could have said you don’t know the answer, or the change in CO2 is too little to be significant, but not to post it is bad form.

    What do you think is the cause of this blip?
    ============================

    [Response: Because I don't want this thread to turn into a discussion of some off-the-wall ludicrous theory, which *is* used by denialsts [edit] to lay the foundation for their contention that it’s ocean solubility, not human emissions, that’s the root cause of CO2 increase.

    I certainly don’t know for sure, but I’d guess that it’s the biosphere that’s responsible for the dip in March 2008.]

  • Brian D // April 8, 2008 at 3:22 pm

    JohnPaul:

    I’ve thought about terminology for a long time, and I’ve concluded that we can’t do better than a suggestion from Joe Romm.

    Let’s be honest. If they weren’t responding to the imminent government action on climate change, they wouldn’t be in denial. You see this behaviour happening any time the environmentalists raise up a small, local fuss that doesn’t suggest government intervention in the people’s lives (i.e. look how modern America views ‘Save the Whales’). And furthermore, what’s the goal here — to get them to accept climate change, so they can openly forestall action, or to get them to accept action, regardless of how they see climate change?

    It’s for this reason that I’ve started calling them “delayers”. Not only is it less aggressive, it’s also closer to the truth (and it also has the subtext that action is inevitable, so people reading the discussions walk away with a very different image).

    HB:

    Thanks for the analysis, as always. Although the main point of the post was clear to me beforehand, this is the clearest I’ve seen the CO2 growth rate expressed, ever. That is, of course, the part that worries me the most.

    [Response: I agree your term is more accurate ... but not as funny.]

  • Hank Roberts // April 8, 2008 at 3:25 pm

    Excellent article. You can tell it’s good by the immediate attempt to fill the thread with a flurry of the usual “but this, but that” digressions.

    Readers, ask yourselves: “How come I keep dragging skep-dumb nonsense to a science blog? Why can’t I recognize this stuff for myself by now?”

  • TCO // April 8, 2008 at 3:45 pm

    Very nice analysis, Tammy.

  • Mike // April 8, 2008 at 3:53 pm

    I check certain delusionist sites daily for their savvy insight into the dark art of statistics. Then I hurry over here to see if you’ve shredded it yet.

    It’s like shooting fish in barrel, isn’t it?

  • Brian D // April 8, 2008 at 3:59 pm

    Mike: It’s like shooting fish in a barrel, isn’t it?

    With a minigun.

    HB: I agree your term is more accurate … but not as funny.

    True. It’s all in the audience, I suppose. On a blog with people who generally “get it”, like this one, I think I’ll start using [edit]. For general use in the public, though, I think that may be too disrespectful. Note how many people think Watts knows what he’s talking about because of the “politeness” air he tries to present (and preserve through comment-pruning)?

  • Paul Middents // April 8, 2008 at 4:07 pm

    The period of linear growth in the late 80’s early 90’s was considered very significant at the time and analyzed by Keeling, et al in Letters to Nature.

    http://cio.eldoc.ub.rug.nl/FILES/root/1995/NatureKeeling/1995NatureKeeling.pdf

    This addresses some of the questions being raised in response to the recent blip. I haven’t tried following this paper forward yet considering that its been cited over 500 times.

  • Dano // April 8, 2008 at 4:24 pm

    Cold La Niña year.

    Best,

    D

  • kim // April 8, 2008 at 4:31 pm

    So Dano? The globe cools and CO2 goes down? How come?
    =================================

    [Response: First of all, the CO2 went UP not down -- just not as much as for March of previous years. Second, the ludicrous idea that southern ocean temperature is responsible for the annual cycle of CO2 variations is trivially easy to disprove. Just look at the data from South Pole station.]

  • Bob G // April 8, 2008 at 4:40 pm

    One quibble. You plotted the seasonally adjusted monthly change. What may be abnormal is the two sequential negative monthly changes that occurred in February and March. Why not just plot total deviation from seasonally adjusted norm?

    FWIW, co2 levels usually jump in April. Such a jump would end the “co2 levels going down” story line. Also, the Feb and March 08 data are higher than the Feb and March 07 data, so there really is nothing to see here.

    [Response: In the Mauna Loa record, there are no fewer than 147 instances of two sequential negative monthly changes in seasonally adjusted CO2.]

  • Lee // April 8, 2008 at 5:14 pm

    BrianD,
    Yes, Watts has - not often, but enough -made insulting intemperate remarks, and then scrubbed them without apology. He called me a hypocrite for declining to contribute a top post to his blog while continuing to press him to correct his errors. Then he removed me altogether. There ahve been others. I think its sad for him, but its worth remembering.

    Anthony just admitted to this in a comment to Onanym, BTW, and also made it clear that he has no intention of revisiting and correcting his errors. His blog does not allow linking to comments, so I’ll paste it below - its in the apology thread for his wordpress troubles.

    Please don’t hesitate to wander over there and comment on all this - politely, of course. grin.

    Onanym (02:07:21) :

    Here’s a challenge for you (that most likely will get caught by the spamfilter):

    Why don’t you stop producing new posts until you have cleaned up you solar imprint post? You have been shown to be wrong, and promised to look further into it. When are the updates due?

    And what is this with removing old posts that were critical to your work that you even replied to?

    REPLY: Thank you for your suggestions. Do you suggest that scientists at universities that write papers that need updates or corrections stop teaching classes or cease work on other papers they are authoring or co-authoring? I think not.

    The other issue is a private matter with one individual, it is not your concern. The goal of your question is to turn that matter into a discussion. Sorry, not gonna happen.

  • John Cross // April 8, 2008 at 5:23 pm

    This is probably getting off topic, but the term I have used in the past to describe the [edit] is necromancer. No matter how many times you slay a theory, they are always able to bring it back to some zombie state of life again somewhere else.

    John

  • Hank Roberts // April 8, 2008 at 5:52 pm

    > record
    And that’s the final record, after the corrections that have to be made to the provisional monthly number.

    It’d be interesting to know how often the provisional monthly numbers have been adjusted in which directions, too.

  • BoulderSolar // April 8, 2008 at 5:54 pm

    Oh come on Tamino, thou aren’t the purest around! I remember your post highlighting the very short term drop in artic ice which included a nice graph. And yet no follow up about the artic ice recovery.

    Both sides propagate any news of some short term change when it helps their argument. I hold AGW advocates to a higher standard as they presumably are more “scientific”

    [Response: Learn to pay attention. I also demonstrated, with zero doubt, that the dip in arctic sea ice this summer was WAY outside the bounds of normal. It was not on the low side of normal, it was so FAR outside the bounds of normal as to constitute a significant shocking event all by itself.

    But the dip in CO2 for March 2008 is well within the bounds of normal.]

  • Hank Roberts // April 8, 2008 at 5:57 pm

    So, Kim ( kim // April 8, 2008 at 4:31 pm)

    Two statements as if factual, both wrong, followed by request to explain.

    Is this just automated copying and pasting, or is there thought behind it?

  • Dano // April 8, 2008 at 6:33 pm

    So Dano? The globe cools and CO2 goes down? How come?

    Because a few denialists have a wish for cooling and decline to be true.

    The rest of the planet sees the long-term trend.

    The rest of the planet also wishes to see the short-term noise, and also wishes to listen to empirical results showing the hand of man has contributed to the warming.

    Now, does the majority of society (denialists excepted) wish to move in an agreed-upon direction to mitigate and adapt? That is the question.

    Denialists/[edit] don’t want to ask or answer the hard questions, they want to distract society with facile questions. More and more of society is learning to not be distracted by such questions. Fortunately.

    Best,

    D

    [Response: And I'm learning to hit the "delete" button for [edit] comments.]

  • Petro // April 8, 2008 at 6:34 pm

    What is abnorml in Mauna Loa February and March numbers is that they are two consecutive Winter months with such low intermonth increse in the CO2 level (0.35 and 0.21). The closest year where Feb and Mar numbers resemble 2008 is 1967, when the increases were 0.17 and 0.54, respectively. However, the current anomaly is still not statistically significant.

    Anyway, let’s speculate! The accumulation of CO2 in atmosphere is dependent on human fossil fuel consumption and seasonal decay of plants in Northern hemisphere. On the other hand, in summertime, when plants are growing, CO2 is turned into sugar and cellulose: CO2 level in atmosphere decreases.

    There is no evidence that human fuel consumption is suddenly decreased during this Winter (unless record cold Winter in China dramatically dropped industrial production there, but I consider this unlikely). Maybe cold Winter has delayed rottening of the plants? Maybe La Niña has enhanced plankton growth in Pacific? Maybe Spring (and plant growth) is coming earlier in the Northern hemisphere?

    None of these suggests the screwball idea of the [edit] that the rising trend of CO2 in atmosphere is not caused by human fossil fuel burning.

  • Dano // April 8, 2008 at 6:34 pm

    John Cross: good comment.

    Hope all is well up there, sir.

    Best,

    D

  • Zeke // April 8, 2008 at 6:56 pm

    Tamino:

    Lucinda has an interesting rebuttal to this post over at her blog, where she criticizes you for analyzing the significance of a one month change instead of a two month change. Personally, I’m not sure how relevant either is in the grand scheme of things, but it appears from her figure that a the two month change is a well outside the norm:

    http://rankexploits.com/musings/wp-content/uploads/2008/04/co2_mauna-loa.jpg

    [Response: Wow! TWO months? That changes everything!!! Unless you look at 3 months, or 4, or ...

    I didn't even know Lucia had posted about this, I got the idea from Anthony Watts.

    I mentioned in this post that because there's noise in just about every observed data set, there will always be at least one which is "wiggling" in a direction that enables [edit] to make a big deal out of it. And the [edit] stay up late at night just *looking* for something — anything — they can seize on to say “See? It’s going the other way!” Of course, in this case they have to resort to restricting themselves to two data points out of 50 years worth of data and crowing about an event that doesn’t even break a record, it just ties one.

    If you really want to see a record-breaker, try this.]

  • Zeke // April 8, 2008 at 6:57 pm

    Bleh, the name of the blogger in the prior post should be Lucia. Thats what I get for hitting submit too quickly.

  • Jim Arndt // April 8, 2008 at 7:04 pm

    Tamino, Now it would be significant if the annual numbers show a decrease, which is very possible. Why, because there has not been a decrease since the records started. I do agree that it is simplistic to take a few months and wave your arms frantically.

  • DocMartyn // April 8, 2008 at 7:05 pm

    The level of CO2 measured is a function of the influx rate into the atmosphere and the efflux rate. The summer’s of the two hemispheres contribute two different efflux rates, as the North Hemisphere is more biologically productive. In essence, CO2 swings between two stable steady states. It is rising because humanity is adding to the influx. The swings in the rise and fall of CO2, and knowing the amount of CO2 humans are adding, gives you an idea of the “average” residency time of CO2 in the atmosphere; about 9-11 years. About on par with the disapearence of 14CO2 following the atmoic H-Bomb tests 50 years ago.

    [Response: The post-nuke decrease of atmospheric C14 also represents migration of much of that CO2 into the oceans, which absorb and emit about 90 Gton every year. The residence time of an increase in total CO2 is much longer than 9-11 years, more like 100 years, and at least part of the increase will persist a lot longer than that.]

  • Dano // April 8, 2008 at 7:05 pm

    [Response: And I'm learning to hit the "delete" button for [edit] comments.]

    Then comes the wailing and rending of garments: ‘Ooooooh! They’re being cennnnsored! Oohhhhh! They’re being stifled! Ohhhhh! Shutting down debaaaaate! Ohhhhhh…etc.

    Best,

    D

  • Zeke // April 8, 2008 at 7:39 pm

    So changes in one month anomalies are not significant, two month anomalies are significant, three month anomalies are (likely) not significant. Where (or how) do we draw the line to decide what timeframe is meaningful in this case? Is there a good statistical tool to tease it out?

    [Response: The two-month change isn't significant either; there's an equally large two-month decrease in the record, and lots of nearly-as-large decreases too. The -0.68 two-month total gives z=-2.75, and that's just about a 1-in-300 event. Out of nearly 600 data points, we have two of them. So the surprising part is ...?

    There are hundreds of climate-related variables being monitored continuously, and [edit] are always looking for one which is at or near a record which they can use to contradict global warming. The chances are *always* overwhelming that there’s at least one they can use. And how far down the barrel did they have to scrape to get this? Take CO2 concentration, remove the seasonal trend, take the monthly difference, then look for how many months they can combine to get something that doesn’t even break the record, or represent a truly statistically significant even. But it looks good in a [edit] way.

    This month it’s CO2, next month it’ll be … who knows?]

  • Hank Roberts // April 8, 2008 at 7:41 pm

    Doc’s channeling Segalstad. And forgetting that the output of fossil carbon dilutes the background C14, which is mentioned in Weart’s history among other places, e.g. http://adsabs.harvard.edu/abs/1981E&PSL..53..349S

  • Hugh // April 8, 2008 at 7:43 pm

    Slightly OT but the Grauniad have just posted a link to a great Vulcan Project animation:
    http://blogs.guardian.co.uk/climatechange/2008/04/spotlight_on_us_co2_emissions.html

    The 3D animation of >=2ppm above ambient is particularly clever I thought.

  • Miguelito // April 8, 2008 at 8:33 pm

    Jebus, these people are really grasping at straws if it has come down to this as being evidence against anthropogenic global warming.

  • The Tuatara // April 8, 2008 at 9:07 pm

    I call ‘em cranks.

    Has the right tone, don’t y’know.

  • TCO // April 8, 2008 at 9:23 pm

    I think you all might want to rethink the [edit] label. It is accurate* for Watts**, but he will hunker down if you use it. Personally, I think people should be able to follow and stay in analytical debates even with harsh comments. But I find that very, very few people are/will. And Watts is certainly not one of those. BTW, he realizes that he is not that sharp, but he persists. I’m actually not sure what the right course is with him. Pain until he learns. Or a more gentle approach. Or just give up. But I do know that he is sensitive. So you might want to lighten up. Leave the thuggishness to me.

    *In the sense of poor thinking even to the point of not understanding his poor thinking.

    **but not ffred or me or SM other SM.

    [Response: I quite agree that you and fred and the SMs don't qualify as "[edit].” Watts does, and I’m starting to suspect that Lucia does as well.

    Its use may well be ill-advised. But it’s the best laugh I’ve had in a while! Oh well… I guess I should put the cause ahead of my sense of humor.]

  • TCO // April 8, 2008 at 9:57 pm

    dude, it is very funny and very apt.

  • TCO // April 8, 2008 at 9:58 pm

    But it just cuts a little close. Like calling GP a pussy or you, Hansen’s bitch or Dhogza an attack dhog. (Actually all those are quite cute…)

  • fred // April 8, 2008 at 9:59 pm

    You do not need a special name for us. We are, you know, just people, but ones who do not agree with you on every particular of every question regarding AGW. At least, not yet.

    There are probably many of you who do not agree with me and my friends on every particular of every question regarding programming or Flemish poetry or the French nineteenth century novel.

    I do not find it necessary to make up derogatory names to call you.

  • cthulhu // April 8, 2008 at 10:05 pm

    Funnily enough I posted on Watts co2 post last night
    http://skepticnonsense.blogspot.com/2008/04/retards-at-watts-blog.html

  • TCO // April 8, 2008 at 10:19 pm

    Watts is very prone to expectation bias. I remember seeing him find a particular upward trending surface station with no micro site issues and say that it had a “classic UHI”. It’s as if he couldn’t even comprehend that there might be an alternative hypothesis (global warming). He’s sort of like some of the types on the other side that I know. He only has room for one possibility.

  • Dano // April 8, 2008 at 10:43 pm

    It’s as if he couldn’t even comprehend that there might be an alternative hypothesis (global warming). He’s sort of like some of the types on the other side that I know.

    You are describing human nature. That’s why we have Platonic and Cartesian systems of inquiry, to help overcome bias.

    Which, BTW, impart their own bias and deemphasize important considerations, which is not surprising as they are human constructs.

    Nonetheless, speaking of human nature, fred states:

    You do not need a special name for us. We are, you know, just people, but ones who do not agree with you on every particular of every question regarding AGW…I do not find it necessary to make up derogatory names to call you.

    This is also human nature, as the divisive wedge politics in America since the mid-1970s has preferenced marginalization phrases to attempt to ‘divide and conquer’, and the Luntz memos outlining the tactics for delaying AGW action were the culmination of that strategy. Indeed, use of marginalization phrases is a hallmark of denialist argumentation and is a marker for that “thought” process.

    Best,

    D

  • TCO // April 8, 2008 at 10:46 pm

    I don’t have a problem with AGW types as long as they don’t date my sister.

  • Neil Fisher // April 9, 2008 at 12:09 am

    Indeed, use of marginalization phrases is a hallmark of denialist argumentation and is a marker for that “thought” process

    Hmm… What does this say about people who apply the “[edit]” label and why is this (or any other label) any different to the “alarmist” label? Short answer: it’s *no* different. Please avoid doing this - it may be funny, but it certainly isn’t helpful, and may be harmful - it certainly puts *me* off!

  • Ken // April 9, 2008 at 12:11 am

    HB - I’ve really been enjoying these quick and simple to follow posts (the PCA series was a bit more taxing).

    Just a heads-up, the March GISS temperature is out and it’s a whopping 0.67 C above baseline. So stand-by for some doubter (that’s my polite term for them) “analysis” that will demonstrate the March CO2 decline and the March temperature rise “proves” CO2 isn’t driving the temperature.

  • Rick // April 9, 2008 at 12:20 am

    I normally just read and learn from Open Mind and other sites. But as the parent of a Down Syndrome son who’s accomplished much in his life I have to speak up in this case. “Skeptard” is deeply offensive in any of several ways. There’s no reason to denigrate those who can’t adequately respond to the ill-considered humor at their expense.

    [Response: I apologize. I'll no longer use the term.]

  • Hansen's Bulldog // April 9, 2008 at 12:34 am

    As Rick’s comment makes clear, the term “skeptard” is offensive to, and at the expense of, many who are completely innocent victims of undeserved ridicule. The fault for propagating its use is mine. Failure to realize this is a shame on me.

    I won’t use the term any more, nor will I permit its use. Future comments containing the offending term will be deleted.

  • Hank Roberts // April 9, 2008 at 12:35 am

    Stooge.

    It’s _the_ right word.

    “… a separate category, people who were interested in obfuscating the issue towards supporting their own agenda, as opposed to people that are interested in the scientific truth. This is an important distinction ….”

    The word applies to people on all spokes at all distances from the center of the political wheel.

    http://www.climateaudit.org/?p=857#comment-52757

  • Hansen's Bulldog // April 9, 2008 at 1:05 am

    I don’t remove comments after having allowed them. But I have attempted to remove the offending word “skeptard” by replacing all its occurences with “[edit]“, except in the cases of Rick’s comment and my replies to his comment. If I’m informed of any I’ve missed, I’ll replace those too.

    This is not to imply that those who used it in commentary are culpable for its use. They were following my lead, the fault is my own. Stupid is as stupid does.

  • Heretic // April 9, 2008 at 1:27 am

    “The fault for propogating its use is mine. Failure to realize this is a shame on me.”
    “I don’t remove comments after having allowed them.”

    Was away for a while and had to catch up with everything. These 2 comments demonstrate your honesty and decency in a way that should be the envy of Watts and the likes of him. I’m even considering buying a recent text on statistics because of you. Keep up the good work.

    [Response: I appreciate your comment, but admitting an offense isn't really cause for praise.]

  • Rick // April 9, 2008 at 1:56 am

    Apology accepted, certainly, and very much appreciated. “Honesty and decency,” indeed.
    I’ll look forward to continued reading, and learning, from what you and others have to say on Open Mind.

  • IANVS // April 9, 2008 at 2:29 am

    Very informative blog, Tamino. thx

    I have a Denydiot to thank for bringing it to my attention.

    Apparently you neutered him a few days ago.

  • steven mosher // April 9, 2008 at 2:30 am

    TCO,

    I wouldnt date your sister with C14

  • Brian Klappstein // April 9, 2008 at 3:36 am

    Jim Arndt:

    “…Tamino, Now it would be significant if the annual numbers show a decrease, which is very possible. Why, because there has not been a decrease since the records started….”

    I don’t think that is true, if you mean annual peak to annual peak. There was an annual peak to annual peak decrease from ‘63 to ‘65 (and also 64 but I’m missing April, May is normally the highest month anyway)

    “…I do agree that it is simplistic to take a few months and wave your arms frantically….”

    That might be true if were only a few months. In fact CO2 growth rates have been decreasing for the last couple of years. This is in line with (as Kim notes) the strengthening of the ocean sinks. It might not be statistically significant (yet), but the patterns of slowing sea level growth, and slowing CO2 growth point to ocean cooling.

    Regards, BRK

  • EliRabett // April 9, 2008 at 3:37 am

    I have to admit to having a slightly different opinion on [edit]. I know enough folk with Down’s syndrome to think of them as people rather than a class. Most of the ones I know are delightful to be with. Since people have a huge range of capability, they are just on one end of it (and for a lot of them not nearly on the far end). OTOH, the one’s labelled [edit] really are either idiots, and not very useful ones at that, or despicable (Seitz, Singer, and my very favorite, Roger Bate).

    One can be oversensitive.

  • fred // April 9, 2008 at 8:15 am

    The various epithets are just marketing. They are a debating tactic, at exactly the same level as the use of expressions like ‘right wing deviationist’, ‘fellow traveller’, ‘capitalist roader’, ‘anti-party clique’, ‘heretic’, ‘whore of Babylon’….

    Their use has no place in the rational discussion of scientific issues on their merits.

  • John Cross // April 9, 2008 at 12:49 pm

    [Response: I appreciate your comment, but admitting an offense isn't really cause for praise.]

    In fact in today’s blog-o-sphere it is cause for praise. It may be a sad state of affairs, but it is true and I also commend you for it.

    Regards
    John

  • caerbannog // April 9, 2008 at 3:03 pm


    Just a heads-up, the March GISS temperature is out and it’s a whopping 0.67 C above baseline. So stand-by for some doubter (that’s my polite term for them) “analysis” that will demonstrate the March CO2 decline and the March temperature rise “proves” CO2 isn’t driving the temperature.

    http://data.giss.nasa.gov/gistemp/graphs/Fig.C.lrg.gif

  • Jim Arndt // April 9, 2008 at 3:41 pm

    Brian Klappstein,

    Sorry, very simply you are wrong see her no decline in yearly CO2
    http://www.esrl.noaa.gov/gmd/ccgg/trends/

  • Ian // April 9, 2008 at 5:50 pm

    Jim Arndt,

    What exactly do you mean by “no decline in yearly CO2″?
    - no decline in annual growth? true, there’s no decline there, either for Mauna Loa or the globe
    - no decline in concentration? true, there’s no decline in concentration, for Mauna Loa or the globe

    I assume you didn’t mean the last 2 months at Mauna Loa when you said “yearly” -there is a decline at Mauna Loa in the last 2 months centered on average seasonal cycles, but not for the globe.

    If you didn’t mean any of these, please clarify.

  • Dano // April 9, 2008 at 6:56 pm

    In fact CO2 growth rates have been decreasing for the last couple of years. This is in line with (as Kim notes) the strengthening of the ocean sinks.

    It is not “in fact”. Maybe a fact made up in your subjectivism-adhering mind** to support your ideology, but not a “fact” out here on the objective surface of planet earth.

    In fact, there’s a cute little dialog box with scrollbar on the right of Jim’s link that allows you to test your subjectivist “facts” against the rest of the planet’s objective facts.

    Best,

    D

    **Golly, how does that square with obsessive Fountainhead and Objectivism followers?

  • Gaelan Clark // April 9, 2008 at 7:01 pm

    caerbannog, and anyone else who can answer this for me—-yes GISS shows +.67 temp increase, but why does this contradict the RSS and UAH measurements?? RSS shows .079 and UAH shows .094 anomoly for same period. Is it because there are clever manipulations of the data over at GISS?—rhetorical question needs no answer.

  • Hank Roberts // April 9, 2008 at 7:22 pm

    Gaelan:
    http://tamino.wordpress.com/2008/01/24/giss-ncdc-hadcru/

    Try reading before posting your PR talking point and saying your “rhetorical question needs no answer” — appear smarter.

    Thought so.

  • caerbannog // April 9, 2008 at 7:42 pm


    caerbannog, and anyone else who can answer this for me—-yes GISS shows +.67 temp increase, but why does this contradict the RSS and UAH measurements?? RSS shows .079 and UAH shows .094 anomoly for same period. Is it because there are clever manipulations of the data over at GISS?—rhetorical question needs no answer.

    If you can’t figure out why the RSS, UAH, and GISS anomaly numbers are different (and why the differences don’t matter), then you’ve got no business posting here.

  • Brian D // April 9, 2008 at 7:56 pm

    Gaelan:

    You’ve made exactly the same mistake that Watts recently made, dissected here. Simply put, the graphs are on different scales (that is, a different temperature baseline is used to compute “zero” anomaly on each), and Jim Arndt’s link is misleading by presenting them all together.

  • Jim Arndt // April 9, 2008 at 8:38 pm

    Ian, I thought I made myself clear. Declining meaning if it is growing then the next year it decreases like 381 one year then the next 382. That is simplistic but that is what I mean. I did agree that you can’t take a few months and say AH HA. So if for 2008 NOAA puts up a negative growth number then that would be significant.

    Brian D, if you think NOAA is misleading then you should take it up with them. I am only using what they provide and they are the providers and host of the Mauna Loa data .

  • Jim Arndt // April 9, 2008 at 9:40 pm

    oooppps meant 382 to 381.

  • Brian D // April 9, 2008 at 10:00 pm

    Jim:

    My mistake; I was responding to a comment that appeared around yours and mistook the name. That comment linked to a [edit] page (one with the four temperature anomaly graphs plotted on the same axis with no conversion), so I assume it’s been removed.

    Sorry for the false accusation; I spoke too soon.

  • Jim Arndt // April 9, 2008 at 10:20 pm

    Brian D, No problem Thanks for the kind response.

  • Brian Klappstein // April 10, 2008 at 1:35 am

    Jim Arndt:

    “…Sorry, very simply you are wrong see her no decline in yearly CO2….”

    Look closely at the peaks on Tamino’s graph. You can see if you squint that the ‘65 peak is lower than the ‘63. Or perhaps you didn’t understand my peak to peak measuring protocol, which is what I thought you meant.

    Regards, BRK

  • Brian Klappstein // April 10, 2008 at 1:53 am

    Dano:

    “…It is not “in fact”…”

    Month over minus 12 month growth rates in the period 2002 to nowtrend down. The data are noisy, and the trend is not likely statistically significant, but down it absolutely is.

    From the objective “surface of the planet earth” the average growth rate in 2003 (month minus 12 month) was over 2.6 ppm per year. For 2007 that same number was 1.9 ppmv per year.

    Regards, BRK

  • Ian // April 10, 2008 at 2:39 am

    Jim Arndt,

    I think I understand you now - I missed the reference to CO2 growth rate in the prior comment.

  • Hank Roberts // April 10, 2008 at 2:50 am

    > not likely statistically significant,
    > but down it absolutely is.

    What kind of idiots do you take us for, sir, to publicly make such an unsupportable statement?

    Oh, wait ….

  • Hank Roberts // April 10, 2008 at 2:51 am

    Feel free to substitute the word “stooges” in my previous question above.

  • dhogaza // April 10, 2008 at 3:07 am

    Look closely at the peaks on Tamino’s graph. You can see if you squint that the ‘65 peak is lower than the ‘63.

    And - NEWS FLASH! - just last week I flipped a coin twice, and IT CAME UP HEADS BOTH TIMES!

    Everything we know about probability and statistical theory was overturned, ya betcha!

  • Hansen's Bulldog // April 10, 2008 at 3:17 am

    The data are pretty easy to find.

    It would seem that in the early 1960s there were two consecutive years in which the annual peak CO2 level was less than the previous year. The 1963 peak at Mauna Loa is 322.24, the 1964 peak is 322.23, and the 1965 peak is 322.16. However, the annual low was steadily rising during that time, and the “smoothed” value (not the seasonally adjusted, but the short-term smoothed) is consistently rising.

  • Dano // April 10, 2008 at 12:04 pm

    Ah. I get it: BRK is reading pre-chewed data to make his assumptions.

    Brian, which think-tank is crunching numbers for it’s readers to make them feel better? Please name it so we can audit their data, complain loudly about their code and their motives, claim the author is being uncooperative to a set of ever-changing and undocumented standards, then sully the author’s name. H*ll, we could get a Congressional hearing or two in as well.

    Anyway, the unreferenced numbers you gave don’t match what the folks here have provided. and what my little spreadsheet got. The first link given even does the work for you (denialists don’t like to follow links, which is what think-tank authors count on; I found this early on.).

    Best,

    D

  • steven mosher // April 10, 2008 at 1:00 pm

    Gaelen , the difference between GISS and RSS and UAH after correcting for the different base period
    is unusally large for march 2008. It’s large but not unprecedented. i think its about a 3sig event. (not doubled checked, so buyer beware ) nothing out of the ordinary.

  • Brian Klappstein // April 10, 2008 at 1:11 pm

    Hank Roberts:

    “…What kind of idiots do you take us for, sir, to publicly make such an unsupportable statement?…”

    What part of my statement is unsupportable? The trend from 2002 to now, although not (yet) statistically significant, is down. It might be some natural variability, but it might not.

    I strongly suspect if people were shown graphs of monthly temperature anomalies in the period 1990 to now, and were told they were the rate of teen pregnancy, they would say something like: “the overall trend was up, but recently it looks like we have turned the corner on this issue….” etc.

    Regards, BRK

    [Response: "... if people were shown graphs ..." is why I get paid to do statistics.]

  • Brian Klappstein // April 10, 2008 at 1:14 pm

    Dano:

    “…Ah. I get it: BRK is reading pre-chewed data to make his assumptions….”

    Actually not. I assume I’ve got the same Mauna Loa database freely available that everyone else has. So your spreadsheet shows a higher CO2 growth for 2007 than 2003? Tell me how.

    Regards, BRK

    [Response: Noise exists. Those who take every wiggle as a reversal of trend ... well, that's another reason I get paid to do statistics.]

  • Dano // April 10, 2008 at 1:24 pm

    You know, looking over at DotEarth and the maluse of data (cherry-picked statistics where starting/ending points are picked to best advantage), and BRK’s (surely innocent) misstatement of CO2 r here, I’m wondering if the denialist industry is trotting out a modified data manipulation tactic.

    That kim bot sure does like to run the output routine that the globe is cooling, doesn’t it? The globe is cooling, CO2 growth rates are down, snow…hmmm…

    Best,

    D

  • Timothy Chase // April 10, 2008 at 2:05 pm

    Regarding fluctuations in CO2 levels, obviously you will want to take into account climate oscillations — warmer temperatures mean less CO2 uptake. However, most of the CO2 uptake in the oceans (and oxygen uptake, too!) takes place in the polar regions. So I suspect that El Nino (which has its strongest effects in the tropics) won’t be as significant as the Pacific Decadal Oscillation, for example, at least with respect to ocean CO2 uptake.

    However, widespread drought is common during El Nino years. This greatly reduces CO2 uptake by plants. The case for this having played a major role in higher CO2 levels in 1998 is fairly strong, and it seems to have played a role in 2002-3 and 2005.

  • Dano // April 10, 2008 at 2:59 pm

    The trend from 2002 to now, although not (yet) statistically significant, is down. It might be some natural variability, but it might not.

    Perhaps you’d like to share with us the rate of change? What’s that number? What are the numbers “you” used (rather, what is the number the think-tank author is telling you)?

    Anyway, the trend is not down from 2002.

    I repeat: from 2002, the growth rate trend is not down.

    To reiterate: the rate of growth of CO2 ppmv, from 2002, is not down.

    It is up. Not down.

    Up.

    Up, not down.

    Here are the data for rate of change.

    Graph them yourself. Don’t trust the misinformation you are parrotting, do it yourself.

    Use a trendline. Any one you wish. Moving average for any period.

    Perhaps you’d like to share with us the rate you graphed, and tell us how that differs from the “information” you were given from the denialist website. Put the two together.

    HTH.

    Best,

    D

  • Brian Klappstein // April 10, 2008 at 3:33 pm

    “….Those who take every wiggle as a reversal …”

    Actually sometimes those wiggles are reversals. And if it was just wiggles in one parameter, you might have a strong point. However, all major global climate parameters, be it sea level growth, lower and middle troposphere temperatures, CO2 growth, surface temperatures, and deep sea temperatures appear to have “flattened” starting in the period 2002-2003 (maybe a bit later for sea level growth which had a stepwise jump in ‘05). The major exception to these flattenng climate trends would be artic sea ice and other NH trends, but then these are not a global parameters.

    You are to a degree hiding behind statistics, analyzing each parameter by itself, and finding that the hypothesis of a recent trend change fails significance tests, but ignoring how remarkably synchronized the change in the major global parameters was starting in 2002.

    Regards, BRK

    [Response: Hiding behind statistics? Misleading by applying statistical significance tests?

    Do you have any idea how ridiculous you make yourself look? I guess not.]

  • Brian Klappstein // April 10, 2008 at 3:47 pm

    Dano:

    I’m using the standard MLO dataset. For example my annual year minus year change for May of 2003 is May 2003 378.54 - May 2002 375.56 = 2.96 ppmv per year. Linear regression on those annual changes (by month) yields a downward trend of -0.06, between Jan 2002 and Feb. 2008.

    I could be making a mistake somewhere, but I don’t think so. I’m not claiming this negative trend is statistically significant, just that it is what it is: negative.

    Regards, BRK

    [Response: The only thing you've done is give us a textbook example of cherry-picking.

    Why not compute the trend from January 2007 to February 2008? Oops, that's positive at +0.28. Does that sound ridiculous? Or would you say it just is what it is?

    You can't say that CO2 levels are dropping, because they're increasing. You can't even say correctly that the *rate of increase* has changed. But you're willing to take a result which fails statistical significance *miserably* (not just by a little) and use it to support, not what's true, but what you *want* to be true. You're in denial -- which makes you a denialist.]

  • Hank Roberts // April 10, 2008 at 3:55 pm

    > not claiming this negative trend is
    > statistically significant, just that it is
    > what it is: negative.

    And you know this “is what it is” how?
    The basis for your belief?

  • Dano // April 10, 2008 at 4:06 pm

    Oooh. OK, I stand corrected:

    I cherry-picked the year with the highest growth since 1998, which is 2002. The slope of the intercept using that year is -.0809x+164.21.

    Sorry. Not used to cherry-picking like that. You can’t eyeball the trend of the rate from, say, 1980, you must graph those few years.

    Nonetheless, using the data over the long term, starting any other year, with a linear trendline or a moving average - 1980, 1990, 2000, is increasing.

    Only when you purposely take the highest values does this happen - global cooling!

    Best,

    D

  • luminous beauty // April 10, 2008 at 4:13 pm

    BRK,

    You are confusing what is, to date, nothing more than a temporal fluctuation with a trend. The flattening you see is what in non-anthropogenically forced times would be seen as a real decrease from natural fluctuation.

  • Ian // April 10, 2008 at 4:22 pm

    I think Brian is suggesting that looking at a simultaneous trend in a large number of measures could be more meaningful than individual analyses of each measure. Brian, in principle there’s nothing preventing this approach. But you should know that it too can, and ultimately should, be treated with a statistical approach. What you describe, for instance, could be tested with a “sign test” based the binomial distribution (null hypothesis would be that pos and neg trends are equally distributed, and you would be looking for a high proportion of pos values in the set of trend measures).

    But what measures would you pick? How would you justify their inclusion – for starters, you’d have to be careful of redundancy across different measures, and you’d want some sort of global coverage for a representative range of forcings. It already sounds like the beginnings of a dissertation to me.

    Next, you still need the statistical tests on individual measures so that you can confidently assign them a positive or negative trend! Brian, the statistics aren’t distracting you from the underlying issues, they’re giving you a principled way of examining the issues.

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