A Positive Human Influence on Global Climate? Robert Mendelsohn, Meet Gerald North!
“[Robert] Mendelsohn’s position is rather similar to yours…. He believes the impacts are not negative at all for the US and most of the developed countries. Most impact studies seem to be showing this. It leads us to think that a little warming is not so bad. Glad I have kept my mouth shut on this issue of which I know so little.”
- Gerald North (Texas A&M) to Rob Bradley (Enron), November 12, 1999
“I agree that the case for 2C warming [for a doubling of manmade greenhouse gas forcing in equilibrium] is pretty strong.”
- Gerald R. North to Rob Bradley, email communication, August 13, 2007.
Yesterday, the Wall Street Journal published my letter-to-the-editor rebutting Kerry Emanuel’s letter, which, in turn, was critical of his fellow MIT climatologist Richard Lindzen’s op-ed, “Climate Science in Denial.”
My arguments opposing those of Professor Emanuel (see entire letter below) are fairly straightforward, but I end with this challenge:
“But when will many climate scientists, including Mr. Emanuel, face Climategate and the fact that the human influence on climate, on net, is as likely to be positive than negative?”
Is this challenge rash, or is it backed by the facts? Well, let’s consider the views of an esteemed climate economist and an esteemed climate scientist. They are, respectively,
Robert O. Mendelsohn (Edwin Weyerhaeuser Davis Professor of Forest Policy; Professor of Economics; and Professor, School of Management)
Gerald R. North (Distinguished Professor, Physical Section, Department of Atmospheric Sciences and the
Department of Oceanography).
Dr. North’s long held sensitivity estimate of 2ºC for a doubling of atmospheric greenhouse concentrations is one-third below the “best guess” of the Intergovernmental Panel on Climate Change (or the IPCC’s best guess is one-half greater than that of Dr. North). That is a big difference, and if you believe Mendelsohn et al. that a 2ºC for 2x results in net positive benefits for the world, then voila!
Is it radical to believe that the human influence on climate, on net, has more positives than negatives for many decades out and even beyond a century or more? After all, the CO2 fertilization effect is a strong positive, and warmer and wetter is going in the right direction for the biopshere…
Perhaps CO2 as the green greenhouse gas is ’closet’ mainstream, if North’s (private) views are considered.
Therein lies one of the peculiarities of the multi-disciplinary climate-change debate, for Gerald North may privately believe something that he is unwilling to admit in public.
Appendix: Robert Bradley Jr. “Doubts on Climate Are Reasonable” (Wall Street Journal letter-to-the-Editor)
Kerry Emanuel’s letter of April 28 illustrates some of the major points of Richard Lindzen’s op-ed, “Climate Science in Denial” (April 22). It is bad enough that Mr. Emanuel refers to major misrepresentations, errors and unethical behavior among scientists involved in the Intergovernmental Panel on Climate Change reports as “minor errors.” But claiming that Mr. Lindzen’s opinions are at odds with basic climate theory, which does not support climate alarmism, is worse.
Mr. Emanuel suggests that such disputed matters as sea-level rise and glacier dynamics (which depend on factors other than global warming) form a “vast body of evidence” for climate change. But no one disputes that climate is changing and has always been changing. So what is his point?
Mr. Emanuel implicitly attacks a recent paper by Mr. Lindzen and Yong-Sang Choi (2009) that, indeed, did have important errors as acknowledged by Mr. Lindzen. But according to the authors, corrections have not altered its conclusion of a low climate sensitivity to man-made greenhouse gases.
The majority of the public is right to discount anthropogenic climate change as an environmental concern. But when will many climate scientists, including Mr. Emanuel, face Climategate and the fact that the human influence on climate, on net, is as likely to be positive than negative?
Robert Bradley Jr.
CEO & Founder, Institute for Energy Research, Houston