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It’s all about me (thane)!

Filed under: — gavin @ 12 November 2009

Well, it’s not really all about me. But methane has figured strongly in a couple of stories recently and gets an apparently-larger-than-before shout-out in Al Gore’s new book as well. Since a part of the recent discussion is based on a paper I co-authored in Science, it is probably incumbent on me to provide a little context.

First off, these latest results are being strongly misrepresented in certain quarters. It should be obvious, but still bears emphasizing, that redistributing the historic forcings between various short-lived species and CH4 is mainly an accounting exercise and doesn’t impact the absolute effect attributed to CO2 (except for a tiny impact of fossil-derived CH4 on the fossil-derived CO2). The headlines that stated that our work shows a bigger role for CH4 should have made it clear that this is at the expense of other short-lived species, not CO2. Indeed, the attribution of historical forcings to CO2 that we made back in 2006 is basically the same as it is now.
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Muddying the peer-reviewed literature

Filed under: — gavin @ 11 November 2009

We’ve often discussed the how’s and why’s of correcting incorrect information that is occasionally found in the peer-reviewed literature. There are multiple recent instances of heavily-promoted papers that contained fundamental flaws that were addressed both on blogs and in submitted comments or follow-up papers (e.g. McLean et al, Douglass et al., Schwartz). Each of those wasted a huge amount of everyone’s time, though there is usually some (small) payoff in terms of a clearer statement of the problems and lessons for subsequent work. However, in each of those cases, the papers were already “in press” by the time other people were aware of the problems.

What is the situation though when problems (of whatever seriousness) are pointed out at an earlier stage? For instance, when a paper has been accepted in principle but a final version has not been sent in and well before the proofs have been sent out? At that point it would seem to be incumbent on the authors to ensure that any errors are fixed before they have a chance to confuse or mislead a wider readership. Often in earlier times corrections and adjustments would have been made using the ‘Note added in proof’, but this is less used these days since it is so easy to fix electronic versions.
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Is Pine Island Glacier the Weak Underbelly of the West Antarctic Ice Sheet?

Filed under: — eric @ 9 November 2009

Guest post by Mauri Pelto

AntarcMapPeltoIt is popularly understood that glaciologists consider West Antarctica the biggest source of uncertainty in sea level projections. The base of the 3000-m thick West Antarctic Ice Sheet (WAIS) – unlike the much larger East Antarctic Ice Sheet – lies below sea level, and it has been recognized for a long time that this means it has the potential to change very rapidly. Most of the grounded West Antarctic ice sheet drains into the floating Ross and Ronne-Filchner ice shelves, but a significant fraction also drains into the much smaller Pine Island Glacier. Glaciologists are paying very close attention to Pine Island Glacier (”PIG” on map, right) and nearby Thwaites Glacier. In the following guest post, Mauri Pelto explains why.
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An open letter to Steve Levitt

Filed under: — raypierre @ 29 October 2009

Dear Mr. Levitt,

The problem of global warming is so big that solving it will require creative thinking from many disciplines. Economists have much to contribute to this effort, particularly with regard to the question of how various means of putting a price on carbon emissions may alter human behavior. Some of the lines of thinking in your first book, Freakonomics, could well have had a bearing on this issue, if brought to bear on the carbon emissions problem. I have very much enjoyed and benefited from the growing collaborations between Geosciences and the Economics department here at the University of Chicago, and had hoped someday to have the pleasure of making your acquaintance. It is more in disappointment than anger that I am writing to you now.

I am addressing this to you rather than your journalist-coauthor because one has become all too accustomed to tendentious screeds from media personalities (think Glenn Beck) with a reckless disregard for the truth. However, if it has come to pass that we can’t expect the William B. Ogden Distinguished Service Professor (and Clark Medalist to boot) at a top-rated department of a respected university to think clearly and honestly with numbers, we are indeed in a sad way.

By now there have been many detailed dissections of everything that is wrong with the treatment of climate in Superfreakonomics , but what has been lost amidst all that extensive discussion is how really simple it would have been to get this stuff right. The problem wasn’t necessarily that you talked to the wrong experts or talked to too few of them. The problem was that you failed to do the most elementary thinking needed to see if what they were saying (or what you thought they were saying) in fact made any sense. If you were stupid, it wouldn’t be so bad to have messed up such elementary reasoning, but I don’t by any means think you are stupid. That makes the failure to do the thinking all the more disappointing. I will take Nathan Myhrvold’s claim about solar cells, which you quoted prominently in your book, as an example.

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Putting the recent Antarctic snowmelt minimum into context

Filed under: — eric @ 27 October 2009

Guest Commentary by Andrew Monaghan and Marco Tedesco

Our study published in mid October in Geophysical Research Letters (Tedesco and Monaghan, 2009) documents record minimum snowmelt for Antarctica during austral summer 2008-2009 and lower-than-normal melt for several recent years, based on a 30-year satellite microwave record. Numerous blogs have cited the results as a challenge to previous studies reporting Antarctic warming, while also steadfastly ignoring other studies with similar results (e.g. Barrett et al., 2009). They have overlooked that these studies show that Antarctic warming has occurred mostly in winter and spring, whereas melting of course occurs in summer. And they oversimplify the causality and hence confuse our prediction for the future. We found that the same mechanism that has primarily caused low snowmelt in recent years will likely change in a manner that will enhance snowmelt in forthcoming decades. A brief summary follows. More »