Review of Useless Arithmetic
May 4th, 2007Posted by: Roger Pielke, Jr.
In the current issue of Nature I review Useless Arithmetic: Why Environmental Scientists Can’t Predict the Future by Orrin Pilkey & Linda Pilkey-Jarvis. Here is my review in PDF. The book’s home page can be found here.
May 4th, 2007 at 4:16 am
This sounds like a book that I should definitely read. I am not suprised by the shortcomings that you mention. It sounds like Pilkey may have “dumbed down” thinking he would reach a wider audience, which is usually a mistake.
With all of your other criticisms, however, you might have corrected the spelling of his surname.
May 4th, 2007 at 7:49 am
I like this statement in the author interview:
“Worse yet, we found that the modelers in many fields (global climate change being an exception) don’t look back at the predictions to see if they were right”. There’s that obligatory “I’m not a denier, don’t attack me” statement that keeps cropping up everywhere.
Incidentally Roger you have unjustified faith in some engineering quantitive models. I’d hesitate to tell you the number of fudge factors involved in fatigue and fracture analysis. Fortunately, commercial airline companies tend to repair cracks. Air forces though tend to believe in a “critical crack size” which is (in my opinion) probably why they inexplicably crash a lot. If there are fewer big errors made in engineering it’s because we usually have at least 3 independent, documented reviews of important work plus as many real-world proof tests as we can manage. That procedure is (in my opinion) what is missing in other disciplines. As useful as models are; the engineer who blindly believes them without some independent checking and back-up is universally regarded as a bad engineer.
May 4th, 2007 at 8:11 am
JamesG- Thanks for your comment. Actually, I have more faith in engineering models in decision making not because they are inherently more accurate, but precisely because of the “fudge factors” and real-world tests that you describe. Thanks!
May 4th, 2007 at 2:23 pm
JamesG:
The lack of validation studies for global climate models is a huge issue in trying to establish a real confidence interval for warming sensitivity predictions. I won’t fill this blog with why, but I’ve published an article on this topic in National Review. You can see it here if interested:
http://article.nationalreview.com/?q=ZmViY2Y3YzY1YmVkYTg4NjczODhkYWU1Mjg1YzhjMTI=
This lack of any real bounds on prediction accuracy is a very strong argument for Roger’s strategy of (crudely put) “track and adapt”.
Jim
May 4th, 2007 at 8:56 pm
Hi Jim Manzi,
Your analysis leaves out two additional very large sources of potential uncertainty/inaccuracy:
1) CO2 is not the only climate forcing agent. In fact, it is probably the best understood climate forcing agent. It’s much better understood than the forcings from aerosols such as black carbon and organic carbon, and sulfates.
Figure SPM-2 has estimates of various climate forcings from 1750 onward:
http://www.ipcc.ch/SPM2feb07.pdf
Note that the range for indirect effect of aerosols varies all the way from -0.3 to -1.8 W/m2. That range is nearly as large as as the total forcing from CO2 (1.66 W/m2).
2) The emission magnitudes and resultant atmospheric concentrations of various forcing agents in the future are unknown. In fact, one thing that can be stated with a great deal of confidence is that the IPCC TAR and AR4 projections of future emissions and atmospheric concentrations of methane, SO2, and black carbon are completely indefensible. (The estimates are much too high for all three…barring a major methane hydrates release.)
Those two problems alone are easily as significant as the question of what the climate sensitivity is with respect to increases in CO2 concentrations.
The IPCC TAR and AR4 projections are pseudoscientific rubbish.
Mark
May 4th, 2007 at 8:59 pm
Hi Jim Manzi,
Your analysis leaves out two additional very large sources of potential uncertainty/inaccuracy:
1) CO2 is not the only climate forcing agent. In fact, it is probably the best understood climate forcing agent. It’s much better understood than the forcings from aerosols such as black carbon and organic carbon, and sulfates.
Figure SPM-2 has estimates of various climate forcings from 1750 onward:
http://www.ipcc.ch/SPM2feb07.pdf
Note that the range for indirect effect of aerosols varies all the way from -0.3 to -1.8 W/m2. That range is nearly as large as as the total forcing from CO2 (1.66 W/m2).
2) The emission magnitudes and resultant atmospheric concentrations of various forcing agents in the future are unknown. In fact, one thing that can be stated with a great deal of confidence is that the IPCC TAR and AR4 projections of future emissions and atmospheric concentrations of methane, SO2, and black carbon are completely indefensible. (They are much too high for all three…barring a major methane hydrates release.)
The IPCC TAR and AR4 projections are pseudoscientific rubbish.
Mark
May 7th, 2007 at 7:30 am
NRO doesn’t seem to permit comments. So: Excellent article, Jim Manzi.
May 8th, 2007 at 4:37 am
Jim Manzi, it seems that by “track and adapt” you’ve left out a key aspect of Roger’s stated position, which could be more fairly characterized as “mitigate and adapt”.
The conclusion of your linked article also seems more than a bit facile and hasty. If we know that “The total impact of global temperatures over the next century could plausibly range from negligible to severe”, why is this knowledge alone not “sufficient[] to guide action”?
We know that our various activities pose significant risks and that the climate is already noticeably changing. Why would we not be justified, on the basis of this knowledge alone, of embarking on a whole array of policies, besides simply throwing more money at research and rolling with whatever punches come – policies such as ceasing global subsidies for fossil fuels, implementing taxes on activities that pose climate risks (thereby influencing a wide range of consumption and investment decisions), providing greater disclosures of ranges of impacts, setting prizes for energy technologies that eliminate CO2 releases, and making coordinated efforts with western nations to improve governance, wealth and climate resilience in the developing world?
Policy makers don’t need “improved forecast reliability” in order to act. They need a little common sense and the political will, both to get past the rent-seeking by special interests that has so exemplified the Bush administration and to abstain from wasting more money on counterproductive pork, and to work seriously with allies.
May 8th, 2007 at 11:08 pm
Tokyo Tom:
Thanks, you raise an excellent question that I’d roughly state as “if we have a risk of global devastation, isn’t that enough to lead a responsible person to take action even in the absence of certainty?”
I’m writing a fairly long article on this exact point right now, but I’d summarize it by saying that yes, a rational actor would be justified in doing something, often analogized as “buying insurance”, but that it’s possible to buy so much flood insurance that you can’t afford fire insurance. Said slightly differently, the Precautionary Principle is a bottomless well of anxieties, but our resources are finite.
I’ll post a link here when the article is published, and hopefully that will provide a much more complete perspective.
Best,
Jim
May 10th, 2007 at 6:34 am
Jim, thanks for the response.
Please note that I’m all in favor of keeping our eye on the most important issue, which is adaptation to expected climate changes to reduce vulnerabilities. No doubt you’re aware of some of the work by Indur Goklany in this area – he is calling for an “adaptive-management approach”
to addressing climate change that in the medium term would focus on:
- reducing vulnerabilities to climate-sensitive problems that are urgent today and might be exacerbated by future climate change;
- reducing barriers to economic growth, advancing human capital, and technological change (which are the major reasons that developing countries are most vulnerable to climate change and to environmental risks in general);
- adopting “no-regret” measures to reduce emissions that would be justified in the absence of the threat of climate change, together with while further R&D in cleaner and more affordable technologies;
- continuing to invest in understanding climate change the science, impacts, and effective policies; and
- monitoring the impacts of climate change to give advance warning of “dangerous” impacts (and to to rearrange priorities for mitigation and adaptation accordingly);
and he is looking at ballpark annual investments somewhere in the range of the estimated costs of Kyoto protocol compliance.
http://www.fraserinstitute.ca/admin/books/files/AdaptiveManagementPost.pdf.
I would be curious to hear your thoughts whether you think Indur is headed in the right direction and the likelihood that the US and other developed nations will have sufficient political will to come to terms with the exceptionally difficult tasks in the first two bullet points. It seems to me that they involve levels of difficulty quite similar to those we have seen with negotiations overs Kyoto or other mitigation approaches.
Sincerely,
Tom
May 12th, 2007 at 6:05 pm
Tom:
I have read some summaries / excerpts of his work, but not the document that you referenced. Thanks, it was an excellent citation.
Yes, I think he is headed in the right direction.
I think the kinds of things he is proposing are far more practical than a mitigation-centric approach. I think it is far easier to get political support for most of these measures than for mitigation, because of the costs of a mitigation strategy would impose.
I don’t think there will be sufficient political support for a Kyoto-level of expenditure on any strategy in the US (assuming you use the WEFA estimate of $300BB per year). I think a “lite” version of his approach at much lower cost is the most likely approach for the US to follow (and, to repeat, I think it is the best approach on the merits).
I believe that from a global perspective the biggest open question is whether the equatorial regions that are most at risk will figure out how to develop economically to a sufficient level to have the wealth and technology to adapt to any climate change that may ultimately occur.
Best,
Jim