The Current Wisdom is a monthly Cato feature written by Senior Fellow Patrick J. Michaels on global climate change. These articles usually feature new and interesting items in the scientific literature with important implications for climate change regulations.

Prior to April, 2011, issues of this Wisdom, which began in 2010, are available at our blog Cato@Liberty (www​.cato​-at​-lib​er​ty​.org/).

This edition departs from our usual routine because of the very vitriolic fight that has broken as the result of publication of a January 27 op-ed titled “No Need to Panic about Global Warming” in The Wall Street Journal. Authored by 16 high-profile scientists, it made common-sense climate arguments that readers of this Wisdom and other Cato publications on climate science and policy are certainly familiar with.

The January 27 piece can be summarized as follows:

• There has been no net warming for “well over ten years;”

• Global warming forecasts confidently made by the UN in 1990 were clearly exaggerations;

• Carbon dioxide, the main “greenhouse” emission, stimulates plant growth;

• Climate scientists on the federal dole have a track record of punishing those who do not express alarmist views;

• Climate alarmism, public funding, and the growth of government and taxation create self-feeding mutual incentives; and

• Doing “nothing” about climate change in the next 50 years has little effect on climate mitigation compared to initiating taxation now.

None of the above are earthshaking propositions to any serious student of climate change. Monthly temperature departures from average show no significant trend going back to 1996. If one is concerned about biasing from the warm El Nino year of 1998, beginning post-2000 yields the same result. The UN was forecasting that global temperatures would be rising around twice the mean rate actually observed in surface temperatures. Greenhouse owners jack up the carbon dioxide concentration of their air several fold to stimulate plant growth. Alarmism breeds funding and new agencies that require more tax dollars, and funding begets tenure. The futility of politically feasible emissions reductions policies has been demonstrated for decades.

By January 30, the New York Times, whose editorial stance on global warming is (to put it mildly) different than that of the Journal, brought in their high-profile environmental blogger, Andrew Revkin, to carp principally about the last bullet item.

His post, “Scientists Challenging Climate Science Appear to Flunk Climate Economics,” claimed that the Journal scientists had misrepresented the work of Yale economist William Nordhaus, quoting the latter’s “wise policy” (no bias there) of slowly introducing a carbon tax.

Nordhaus responded that the Journal piece “completely misrepresented my work.”

At that point, Revkin opened up the controversy to commentary. Readers can decide for themselves.

Here is Nordhaus’s complete comment on the Journal op-ed:

The piece completely misrepresented my work. My work has long taken the view that policies to slow global warming would have net economic benefits, in the trillion of dollars of present value. This is true going back to work in the early 1990s (MIT Press, Yale Press, Science, PNAS, among others). I have advocated a carbon tax for many years as the best way to attack the issue. I can only assume they either completely ignorant of the economics on the issue or are willfully misstating my findings.

And here is the response of the Journal article authors:

We have accurately represented Professor Nordhaus’s findings in our Wall Street Journal editorial of 01–27-12, while making and intending no statement regarding his policy beliefs and advocacy. In his 2008 book, A Question of Balance, Weighing the Options on Global Warming Policies, Professor Nordhaus provided the computed discounted costs and benefits for a variety of policies, assuming the IPCC central value for warming due to increased atmospheric CO2 (3 degrees C for doubling of CO2).

He finds (Table 5.3 of the book) that a policy of delaying greenhouse gas controls for 50 years gives a benefit-to-cost ratio just slightly less than his “optimum” policy. The optimum policy is a universal harmonized carbon tax, which Professor Nordhaus advocates. It starts small and is increased gradually over decades. In terms of net benefits, the 50-year-delay policy is far better than more aggressive policies that would severely limit atmospheric concentrations of CO2 or model-calculated global temperature rises.

Both the 50-year-delay policy and the optimum policy allow world economies to continue to develop with relatively little disruption. Aggressive policies considered in the book do not have this characteristic and display sharply higher abatement costs and lower benefit-to-cost ratios.

As we note in the Wall Street Journal editorial, several more aggressive policies are negative return propositions.

Furthermore, in Chapters I and VI, Professor Nordhaus takes pains to explain that the requirement of universality of policy application is critical; regional, national, or group participation differences can be expected to lower policy effectiveness, perhaps substantially: “… there are substantial excess costs if the preponderance of sectors and countries are not fully included. We preliminarily estimate that a participation rate of 50 percent, as compared with 100 percent, will impose an abatement-cost penalty of 250 percent.” (Chapter 1, p.19). Therefore the optimum policy should be considered an ideal upper limit that may not be achieved in real world application.

We wish to emphasize once again that the above assumes that the IPCC climate results are correct and that significant environmental damage would result, both of which we strongly dispute. The statements made in the Wall Street Journal editorial report Professor Nordhaus’s findings accurately and do not bear on his policy advocacy.

Here is Table 5.3:

Of course, that wasn’t the end.

It seems that if one ever needs to start a fire in the woods, simply rub two climatologists together. So, in the wee hours of February 1, a response to the Journal article, signed now by 38 scientists, was published.

For clarity, let’s call this one “Trenberth et al.”, for its senior author, Kevin Trenberth of the U.S. National Center for Atmospheric Research.

Summarizing Trenberth et al.:

• The authors of the original Journal article were largely not climate scientists, and those that were, held “extreme views.”

• Warming has not “abated” in the last decade.

• Scientific societies worldwide concur that “the earth is heating up and humans are primarily responsible”. More than 97% of all actively publishing climate scientists “agree that climate change is real and human caused”.

• ”… The transition to a low-carbon economy will not only allow the world to avoid the worst risks of climate change, but could also drive decades of economic growth.”

Trenberth et al. is surprisingly weak and incomplete. The 16 original authors are all individuals that are highly competent in their fields, most are physicists of one stripe or another, and all can read and summarize a scientific literature. In fact, most would hold that climate science is nothing more than applied physics.

“Extreme views” lie in the eye of the beholder, and science only grudgingly backs away from established paradigms. For example, despite the obvious jigsaw-puzzle fit of the earth’s continents, it took 100 years of bickering before continental drift was accepted over geological stasis. And, in this case, the “extreme view” of the most prominent climate scientist of the 16, MIT’s Richard Lindzen, is hardly an outrage.

Lindzen holds that the “sensitivity” of surface temperature to changes in atmospheric carbon dioxide has been overestimated because of an inaccuracy in the way that computer models magnify warming. In and of itself, it is mainstream, not extreme, to entertain the hypothesis that doubling carbon dioxide on its own would only cause a bit more than 1 degree (C) of global surface warming. Computer models arrive at much higher values, around 3.5°C, by amplifying the carbon dioxide effect because a slightly warmer atmosphere contains more water vapor, which itself is a potent greenhouse gas. Clouds are also changed in a way that enhances warming. There is evidence from the outgoing radiation signal of the earth that the effects of water vapor and clouds have been overestimated.

The 38 must somehow disagree with Susan Solomon, whose 2010 article in Science attributing the lack of recent warming—that the 39 deny—to unanticipated changes in stratospheric water vapor with no known cause.

The 38 must somehow disagree with the global temperature sensing from satellites, which also shows no net warming for the last 14 years. Now, one could argue that the satellites are measuring temperatures above the surface in the lower atmosphere, but the computer models that the 38 find so accurate, predict that the lower atmosphere should be warming faster than the surface over most of the planet.

Finally “more than 97% of all actively publishing* climate scientists agree that climate change is real and human caused” is probably an underestimate, as virtually everyone acknowledges that the surface temperature is warmer than it was, and that multifarious human activities have some influence on climate. Rather, he misses the point well-made by the original Journal article, which is that the rise in surface temperature is clearly below the values first forecast by the UN in 1990. The core—unsettled—issue in climate science is the “sensitivity” of temperature to carbon dioxide, and there are several independent lines of evidence, including the surface temperature history and the water vapor problems, that argue that it has been substantially overestimated.

In global warming, it’s not the heat, it’s the sensitivity. But don’t expect much sensitivity and expect a lot of heat when climatologists voice their opinions.

* The part about “actively publishing” is saved for another day. The climategate emails—and there are plenty by, to, or about these 39 scientists, detail how difficult it is to publish anything they disagree with, thanks to intimidation and manipulation of editors, blackballing of those who disagree with them, and other blood sports.