Census, Intimidation, and Global WarmingMike Rappaport

I am sometimes asked why I am so hostile to the “global warming movement.”  How can I, a mere law professor, know enough to be skeptical of the evidence provided by this movement? 

This is a good question — and one that I take seriously — but I do believe there is an answer to it.  Based on experience, I am skeptical about the claims coming out of the “global warming movement.”

Sadly, we have seen this all before.  In fact, Arnold Kling provides a great example:

My concern is with how “scientific consensus” is reached. In economicsin the 1960’s, there was a “scientific consensus,” embedded insophisticated macro-econometric models, that inflation reflected acompetition over income shares, and that government policies tointerfere with wage- and price-setting were the solution. MiltonFriedman’s contrary views were outside the “scientific consensus.”

By 1985 or so, the “scientific consensus” had shifted, in partbecause policies based on that consensus were tried in the 1970’s,leading to the worst macroeconomic performance of the post-war period.

By the 1990’s, large macro-econometric models had pretty muchdisappeared from the economics literature. The problem withmacro-econometrics is that the models continually broke down out ofsample. That is, a model estimated through 1969 would work terribly inpredicting the early 1970’s. A model estimated through 1975 would workterribly in predicting the late 1970’s, and so on.

Milton Friedman’s dissenting views of 1967 are close to the consensus views today.

I wish that climate-change models did not remind me so much ofmacro-econometric models. I wish that the contempt that the Leftexpresses for dissenting views in climate science did not remind me ofthe contempt that the Left expressed for Milton Friedman. And I wishthat the debate over climate change were being waged over substance,rather than [based on the presumed motivations of the debaters]

I worry that the environmentalists are motivating themselves tostage a religious war over global warming. My guess is that mankindwill not be well served by such a religious war.

Alas, the “consensus” which is so paraded around by the global warming movement is what gives me the biggest pause.  The consensus appears to be produced by intimidation and pressure from various ideological and special interest groups.   Letters from Congress referring to opponents of the global warming consensus as “deniers”  (as in Holocaust deniers) are just the tip of the iceberg.

As with the Condorcet Jury Theorem, consensus is only informative if it is produced by independent judgments that have not been coerced.  This is exactly what we don’t have in this area.

After all, if the evidence was so good, it would not be necessary to pressure so many people.