Today my new paper on climate change science and economics was published in the International Journal of Environmental Research and Public Health, a peer-reviewed journal. The paper is unusual from a number of different perspectives.
Some Unusual FeaturesFrom a policy perspective, the paper’s conclusions include the following:
· The economic benefits of reducing CO2 emissions may be about two orders of magnitude less than those estimated by most economists because the climate sensitivity factor is much lower than assumed by the United Nations because feedback is negative rather than positive and the effects of CO2 emissions reductions on atmospheric CO2 appear to be short rather than long lasting.
· The costs of CO2 emissions reductions are perhaps an order of magnitude higher than usually estimated because of technological and implementation problems recently identified.
· CO2 emissions reductions are economically unattractive since the few benefits remaining after the corrections for the above effects are quite unlikely to economically justify the much higher costs unless much lower cost geoengineering is used.
· The risk of catastrophic anthropogenic global warming appears to be so low that it is not currently worth doing anything to try to control it, including geoengineering.
From a historical perspective, the paper builds on my Comments on Draft Technical Support Document for Endangerment Analysis for Greenhouse Gas Emissions under the Clean Air Act, prepared for the US Environmental Protection Agency in early 2009, by presenting an expanded version of a few portions of that material in journal article format, incorporating many new or updated references, and explaining the implications of the science for the economic benefits and costs of climate change control. It is also particularly noteworthy for appearing in a peer-reviewed journal rather than the “gray literature,” such as a report to EPA, where many skeptic analyses end up–something that warmists never fail to point out. Although this article was not written for EPA, it has major implications for the scientific validity (or lack thereof) of the December 2009 EPA Endangerment Finding and the economics that EPA and many economists have used to justify current efforts to regulate the emission of greenhouse gases under the Clean Air Act, cap-and-trade schemes, and other approaches to controlling climate change.
From a scientific perspective, the paper starts with a detailed examination of the scientific validity of two of the central tenets of the AGW hypothesis. By applying the scientific method the paper shows why these two tenets are not scientifically valid since predictions made using these hypotheses fail to correspond with observational data. (See primarily Section 2.)
From an economic perspective the paper then develops correction factors to be used to adjust previous economic estimates of the economic benefits of global warming control for these scientifically invalid aspects of the AGW hypothesis. (See primarily Section 2.) It also briefly summarizes many of the previous analyses of the economic benefits and costs of climate control, analyzes why previous analyses reached the conclusions they did, and contrasts them with the policy conclusions reached in this paper. (See primarily Section 5.) It also critically examines the economic costs of control. (See primarily Section 3.)
From a methodological perspective, the article argues that economic analyses of interdisciplinary issues such as climate change would be much more useful if they critically examine what other disciplines have to say, insist on using the most relevant observational data and the scientific method, and examine lower cost alternatives that would accomplish the same objectives. (See primarily Section 1.) These general principles are illustrated by applying them to the case of climate change mitigation, one of the most interdisciplinary of public policy issues. The analysis shows how use of these principles leads to quite different conclusions than those of most previous such economic analyses.