Consensus Shmensus

Months ago, indefatigable watchdog Anthony Watts called out Organizing for Action (OFA) for declaring, in a Tweet issued in President Obama’s name, that “Ninety-seven percent of scientists agree: Climate change is real, man-made and dangerous.”

OFA was invoking a study in Environmental Research Letters by John Cook and colleagues, who supposedly found that 97% of climate scientists accept the “consensus” position on climate change. Cook manages Skeptical Science, a Web site dedicated to debunking climate “skeptics.”

As Watts and others, such as Andrew Montford of the Global Warming Policy Foundation, point out, Cook et al. did not attempt to estimate the number or percentage of climate scientists who agree or disagree that climate change is “dangerous.”*

But what about Cook et al.’s widely reported finding that 97% of climate scientists believe most of the 0.7°C warming since 1950 is due to the buildup of anthropogenic greenhouse gases? Does the Cook team actually demonstrate overwhelming agreement with that core “consensus” position of the International Governmental Panel on Climate Change (IPCC)?

Not by a long shot, argue University of Delaware climatologist David Legates and three colleagues in Climate “Consensus” and Misinformation. In fact, less than 1% of the 11,944 science papers (actually, just the abstracts) surveyed by the Cook researchers express agreement with the so-called consensus.

Of the 11,944 abstracts examined by Cook et al., 66.4% percent expressed no position. Cook and his colleagues claim that 97.1% of the 33.6% of the abstracts that expressed an opinion, or 32.6% of the entire sample, agree with the IPCC consensus position. “However,” contend Legates et al., “inspection of the authors’ own data file showed that they had themselves categorized only 64 abstracts, just 0.5% of the sample, as endorsing the standard [IPCC] definition. Inspection shows only 41 of the 64 papers, or 0.3% of the sample of 11,944 papers, actually endorsed that definition.”

So what is it that 97.1% of 33.6% of the science study abstracts actually agree on? The proposition that anthropogenic greenhouse gases are responsible for some unspecified portion of the warming of the past 50 years. And guess what? Just about every prominent skeptic, including John Christy, Roy Spencer, Patrick Michaels, and Richard Lindzen, agrees with that as well. As an attempt to discredit skeptics, the Cook et al. study is a complete bust.

In the Legates team’s press release, co-author Christopher Monckton cheerfully concedes that “more than 0.3% of climate scientists think Man caused at least half the warming since 1950.” Nonetheless, he observes, “only 0.3% of almost 12,000 published papers say so explicitly,” and “It is unscientific to assume that most scientists believe what they have neither said nor written.”

* Cook et al. argue as if simply establishing a consensus that climate change is “real” is enough to justify “public support for climate policy,” such as carbon taxes, renewable energy mandates, greenhouse gas regulations, cap-and-trade, and the like. But not even a consensus that climate change is “dangerous” would settle the critical policy questions.

The world is a dangerous place, and the resources available to address its many perils are finite. What policy makers need to know is not just whether X is dangerous but how dangerous X is compared to other problems, how many lives can be saved via interventions addressing X versus interventions addressing other challenges, and what are the potential risks associated with the proposed solutions to X.

Bjorn Lomborg’s Copenhagen Consensus project repeatedly finds that many threats to global welfare such as malnutrition, trade barriers, and childhood diseases threaten more lives than climate change, and that proven methods for addressing those problems can save many more lives than can an optimal carbon tax, R&D in low-carbon technologies, or any other climate policy. 

Indeed, since even a politically-impossible carbon tax that eliminated all U.S. carbon dioxide (CO2) emissions tomorrow would avert only a hypothetical 0.2°C of warming by 2100, it is far from evident that any politically-feasible carbon tax or emission-control strategy would yield any discernible health or safety benefits. 

Most importantly, Cook et al.’s fixation with “consensus” as a mandate for “policy” disregards the whole issue of unintended consequences. Responsible policy makers consider whether the potential side-effects of any proposed intervention might make corrective action a ‘cure’ worse than the disease.

For example, most people might agree that chemical weapons-wielding Syrian dictator Bashar Assad is “dangerous.” That, however, hardly clinches the case for bombing Syria’s weapons stockpiles. Still less does it justify launching an Iraq-style invasion. Rightly or wrongly, many U.S. policymakers fear the potential repercussions of U.S. military intervention in the Mideast more than they fear Bashar.

Similarly, many “skeptics” see greater peril to human welfare from coercive de-carbonization than from mankind’s continuing use of fossil fuels. UCLA Prof. Deepak Lal expresses the point with his usual eloquence:

“The greatest threat to the alleviation of the structural poverty of the Third World is the continuing campaign by western governments, egged on by some climate scientists and green groups, to curb greenhouse gas emissions, primarily the CO2 from burning fossil fuels.  To put a limit on the use of fossil fuels without adequate economically viable alternatives is to condemn the Third World to perpetual structural poverty.”  

 – Deepak Lal, Professor Emeritus of International Development Studies at UCLA and Professor Emeritus of Political Economy at University College London, in his new book, Poverty and Progress: Realities and Myths About Global Poverty.