A while back, in a post semi-defending Gore et. al's backing of science showing a connection between hurricanes and climate change, I invoked a study by Tom Wigley and colleagues. It occurred to me that it might be nice to hear what Wigley himself had to say, so I asked him. He responded, and I'm publishing his response below (I added all the links). Note: Wigley made it clear he'd rather spend his time on science than blogging, and doesn't expect to be available to address any responses. For what it's worth.
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Tom Wigley:
(1) Middle vs extremes. I agree that this misrepresents the science. There is no denial extreme in the credible science literature. The literature differences are a matter of scale -- how big will the warming be (or, more technically, what is the range of warming with an associated confidence interval (C.I.))? This can be determined using good science -- see below. What to do is a policy issue -- but it should be informed by good science (which includes economics).
(2) Re: the IPCC TAR range of 1.4-5.8C (determined, by the way, using the Wigley & Raper MAGICC model), markbahner said that the probability of warming less than 1.4C was 50% and the probability of warming greater than 5C was zero.
IPCC did not assign a probability to the 1.4-5.8C range. It was recognized that to so may have been useful, but it was beyond the state of the science (insofar as IPCC can only review the science, not do new science). So Sarah Raper and I did the appropriate probabilistic calculations:
Wigley, T.M.L. and Raper, S.C.B., 2001: Interpretation of high projections for global-mean warming. Science 293, 451-454.
We found that there was a non-zero probability of warming less than 1.4C and a non-zero (but smaller) probability of warming above 5.8C. You can estimate the probabilities from the above-cited paper. We found the 90% C.I. to be 1.68C to 4.87C.
MAGICC can be downloaded as user-friendly software from www.cgd.ncar.edu.
(3) The only paper I have published on hurricane science is the 2006 PNAS paper. Roger Pielke Jr. has published much more on hurricanes, but nothing on hurricane science. The PNAS paper, however, is really about the cause of SST changes in hurricane/tropical cyclone genesis regions. There is little doubt that part of this warming can be attributed to human factors (primarily GHGs). We accept a wealth of scientific evidence that greater SSTs means greater hurricane intensity -- but there are considerable uncertainties in the strength of this relationship.
Roger is quite right in saying "so what" to the numbers of papers we may have published on this topic. We are both quite knowledgeable about the issues, so can both claim to give informed opinions.
(4) While I eschew the idea of a "middle", I note that the WRE paper, which determines emissions requirements for CO2 concentration stabilization (and which has been supported by a lot of subsequent economic literature) could be said to represent the middle ground.
Wigley, T.M.L., Richels, R. and Edmonds, J.A., 1996: Economic and environmental choices in the stabilization of atmospheric CO2 concentrations. Nature 379, 240-243.
(5) Al Gore, in his movie, supports the ideas of Pacala and Socolow (who say we can follow a pathway to CO2 concentration stabilization at an acceptable level, at least to 2055, using present technology) ...
Pacala, S. and Socolow, R., 2004: Stabilization wedges: Solving the climate problem for the next 50 years with current technologies. Science 305, 968-972.
I (and a number of my colleagues) do not agree with this. We believe that the above paper is flawed (for some insight into this, see ...
Gibbs, W.W., 2006: Plan B for energy. Scientific American 295(3), 102-114.)
... and that the technological challenge of achieving concentration stabilization is much greater and more urgent than either Pacala and Socolow, or Gore, seem to think. Two papers dealing with this are ...
Hoffert, M.I., Caldeira, K., Jain, A.K., Haites, E.F., Harvey, L.D.D., Potter, S.D., Schlesinger, M.E., Schneider, S.H., Watts, R.G., Wigley, T.M.L. and Wuebbles, D.J., 1998: Energy implications of CO2 stabilization. Nature 395, 881-884.
Hoffert, M.I., Caldeira, K., Benford, G., Criswell, D.R., Green, C., Herzog, H., Jain, A.K., Kheshgi, H.S., Lackner, K.S., Lewis, J.S., Lightfoot, H.D., Mannheimer, W., Mankins, J.C., Mauel, M.E., Perkins, L.J., Schlesinger, M.E., Volk, T. and Wigley, T.M.L., 2002: Advanced technology paths to global climate stability: Energy for a greenhouse planet. Science 298, 981-987.
Comments
View as Flat
Bart Anderson Posted 4:50 am
12 Jan 2007
One observation - almost all the links cited are behind paywalls. This means that most Web readers are shut out from this information which is critical for understanding global warming and our survival.
This doesn't make any sense at all. I understand the problems of financing scientific publications, but we need to find a new model for delivering critical scientific information. Times have changed and what worked in the 40s no longer works today.
Popular science writing can help, but there's nothing like reading the original papers.
Bart Anderson
Energy Bulletin
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Benny Big Eye Posted 5:05 am
12 Jan 2007
So what does Roger do? Pielke is just trying to insulate himself against charges that he's little more than a contrarian whose blog functions as a chum line to lure in journalists.
Wigley may be more respected in science and he may have published widely in science, but he is not often heard from, unlike some media stars who blog.
Thanks for this, David.
Benny Big Eye
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bhurley Posted 5:38 am
12 Jan 2007
These are mainstream scientific publications; Scientific American and Science can be found in almost any good public library, and Nature can be found in any university science library. I agree that it would be nice to be able just click and see the references, but it costs money to print magazines and pay editors. Even Al Gore's Inconvenient Truth DVD isn't free.
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GRLCowan Posted 6:14 am
12 Jan 2007
I'm no..., "breaking the Ca-CO2 bond requires substantial energy", without quantifying "big" or "substantial". This is known as handwaving, and seems to be done here when precision and accuracy would make the mentioned difficulties seem less difficult.
Also, it makes more sense to speak of breaking the CaO-CO2 bond, since CaO, not elemental calcium, is the solid product.
--- G. R. L. Cowan, former hydrogen fan
Oxygen expands around B fire, car goes
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Bart Anderson Posted 6:59 am
12 Jan 2007
What I'm arguing is something different. We are faced with a situation in which it is critical to get accurate, complete information spread to the widest audience possible. As a sometimes web developer, I know that every impediment you place in the path of a reader reduces the readership drastically.
One example of how paywalls sabotage the effort - when I or any other blogger look for research or supporting information, we look on the web first. If a document is available, we quote a few sentences and link back to the original. If I have to drive to the library to get it and copy the text, I will not bother 99% of the time. Due to the amplifying effect of the blogosphere, a good online article can quickly get tens or hundreds of thousands of reads.
Meanwhile, Exxon-Mobile is busy crafting press releases, advertisements and online presentations. If they can get scientists to cast doubt on global warming, they do everything they can to make that information freely available. They do not hide it behind a paywall.
And we wonder why the population is confused about climate change?
I believe there are efforts afoot within the scientific community to make research articles more readily available. We should support these.
The fact that it costs money to generate information is not an impediment. Many funding models are possible. Many documents are traditionally made available for the public good.
With little effort, publications could identify those articles of critical importance and make those freely available.
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David Roberts Posted 7:03 am
12 Jan 2007
www.grist.org
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jjwfmme Posted 8:23 am
12 Jan 2007
That's actually kind of an interesting question. If you Google him, he comes up as a social scientist, a political scientist, and an atmospheric scientist. To me, these three disciplines are very different. There's a big, big difference between say, Max Weber and Max Planck. It's sometimes not clear in what capacity Dr. Pielke is speaking. Is he prescribing to us a scientific view, a political view, or what?
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Steve Bloom Posted 7:21 pm
12 Jan 2007
Actually there are two RPs: Jr. is the political scientist referred to in the post, and Sr. is the atmosphere scientist. Each in his own unique way drives people nuts. Jr. does have some arguable expertise in the public policy aspects of hurricanes, but he spends considerable time trying to insinuate himself into a leading role in the scientific debate. He is of course not qualified to shine the shoes of someone like Tom Wigley.
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markbahner Posted 10:55 am
14 Jan 2007
That's close, but my exact words were, "The simple fact is that there is approximately a 50/50 chance that the warming will be less than 1.4 deg C...and there is virtually no chance (far less than 1 percent) that the warming will be over 5 deg C."
Dr. Wigley continues, regarding the "projections" in the IPCC Third Assessment Report (TAR), "IPCC did not assign a probability to the 1.4-5.8C range. It was recognized that to so may have been useful, but it was beyond the state of the science (insofar as IPCC can only review the science, not do new science)."
That extraordinary comment provides compelling evidence of the deep scientific pathology of the current state of climate "science." I've personally developed two sets of my own probabilistic predictions for methane atmospheric concentrations, CO2 emissions and atmospheric concentrations, and resultant lower tropospheric temperature increases. The second set is here:
My predictions
My own probabilistic predictions were developed in my spare time, almost certainly with less than 100 hours of research, thought, and calculations, and only a pocket calculator. By 2001, when the IPCC published the TAR, there had obviously been two previous assessment reports, with more than a full decade having passed since the first assessment report was published in 1990. In that time, hundreds, if not thousands, of people were working full time on climate research. Dr. Wigley is stating that the entire climate change community was unable to come up with probabilistic predictions in over a decade of research, including countless conferences (in some very nice locales) and a great many powerful computers running climate simulations. I'm sorry, but if a simple set of probabilistic predictions for methane atmspheric concentrations, CO2 emissions and atmospheric concentrations, and resultant lower tropospheric temperature increases was beyond the IPCC and the climate change community after more than a full decade of research by hundreds or thousands of people, it's simply because the IPCC and climate change community aren't very interested in doing science.
Mark Bahner
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markbahner Posted 10:57 am
14 Jan 2007
I commend Drs. Wigley and Raper (WR) for injecting a modest amount of science into the IPCC process for developing "projections" based on "scenarios." As he reports, the WR paper calculated a 5% probability of warming less than 1.68C, a 50% probability of warming less than 3.06C, and a 95% probability of warming less than 4.87C. Therefore, WR and I agree that the probabililty of warming of 5 deg C or more is very remote (with WR estimating the odds at more than 20 to 1, and me at more than 100 to 1).
The differences between their predictions and mine regard the probability of warming near 1.4 deg C and 3.1 deg C. They estimate less than 5 percent chance of warming less than 1.4 deg C, whereas I estimate approximately a 50 percent chance of warming less than 1.4 deg C. Also, they estimate approximately a 50 percent chance of warming more than 3.1 deg C, whereas I estimate the probability of warming more than 3.1 deg C at less than 5 percent.
How do these differences in predictions arise? Well, the main reason for the differences is that Wigley and Raper assumed that all IPCC TAR scenarios had equal probability of occurrence, whereas I estimated that the most probable climate forcing for the 21st century would be somewhat less than the B1 scenario:
IPCC TAR scenarios and resultant temperature increases
So WR assume equal probability for all IPCC TAR scenarios. Is this a scientifically valid assumption? No, it is not. This is not a close call. Even a layperson can see that the assumption of equal probability is scientifically invalid. James Hansen's Keeling Lecture compared various IPCC scenarios with actual increases in CO2 and methane:
James Hansen's Keeling Lecture, see pages 42-44
Increases since 1990 of both methane and CO2 have been at the very bottom of all IPCC TAR scenarios. The WR assumption of equal probability for all scenarios is like assuming a straight-A student has equal probability of getting an A, B, C, D, or F in the next class he or she takes.
To summarize: The IPCC TAR scenarios are completely invalid, as a matter of science. The fact that the TAR had no probabilistic estimates is clear evidence of the pathology of the current state of climate "science." The Wigley and Raper paper is a significant improvement on the IPCC TAR. However, the WR assumption of equal probabilities for all scenarios is scientifically invalid. If WR had used a "50 percent probability" forcing near or less than the B1 scenario, as would be appropriate, their calculated probability of warming of more than 3.1 deg C would be well below 50 percent, and their calculated probability of warming less than 1.4 deg C would be much higher than 5 percent. Their calculations would produce results near mine, in fact.
Mark Bahner
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jjwfmme Posted 12:48 pm
14 Jan 2007
Only, there's this little matter of the law of conservation of... oh, nevermind.
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