This is the second in a series of articles with "Stand-up Economist" Yoram Bauman taking the pro-global-warming-alarmism position and being debated by me and other more expert people such as the Cato Institute's Jerry Taylor and the Heartland Institute's James Taylor. The entire series should be able to be found by searching my blog for "Bauman", with this link:
http://www.rossputin.com/blog/index.php/a?s=bauman&sentence=AND&submit=Search

Jerry Taylor of the Cato Institute has been generous enough with his time to respond to yesterday's "guest posting" by Yoram Bauman about "Libertarians and Global Warming". I hope you find it interesting, as we continue this debate. If you're interested in the discussion, I recommend you also read the comments to the articles in this series, beginning with the first article, linked above.

I actually agree with almost all of the above despite the fact that the author went out of his way to single out a speech I made in 1998 for ridicule. I am not at all embarrassed by the speech in question: I think it was a fair and reasonable summary of the science at the time and of the uncertainties that lingered as of 1998. As the scientific literature has evolved, of course, the summary of the science should evolve as well. Hence, as we learned more about the orbital drift that distorted the satellite readings of earth's temperature, we were able to resolve some of the mysteries that existed at that time.

The author is correct to note, however, that I made "a totally wrong claim that 4000+ scientists signed an anti-global-warming statement." I meant to say 400+ scientists signed the statement in question (the so-called Heidelberg Appeal). It was an honest (albeit annoying) typographical error.

While I don't pretend to speak for libertarians in general, I think an honest examination of the libertarian community would find that the beliefs Mr. Bauman is attacking are not as widely spread as he thinks. For instance, Prof. Pat Michaels - a senior fellow here at Cato who holds a PhD in climatology and who is widely published in the scientific literature on this matter - agrees that anthropogenic emissions are the main driver behind the warming trend of the past several decades. Moreover, he thinks the IPCC reports are fairly reasonable (albeit not perfect) summaries of the scientific literature (which maybe shouldn't surprise - he is a member of the IPCC). He believes, however, that future warming will be at the lower end of the IPCC forecasts and that the economic costs will prove modest given the distribution of that warming.

Moreover, Cato's latest salvo addressing this issue - Indur Goklany's "What to Do about Climate Change" - makes none of the arguments Mr. Bauman chastises libertarians for making. If Mr. Bauman gets a chance to read the piece, I would be interested in his comments.

That having been said, let me note that there are very good reasons for people (not just libertarians) to be skeptical of expert scientific consensus regarding environmental doom given the track record of that community. Consensus from that community once told us that industrial chemicals were the cause of a modern cancer epidemic; that population growth would outpace food production and usher in a Malthusian apocalypse; that mineral scarcity would soon turn off the industrial engines of the Western world; ad infinitum. Conspiracy theories are not necessary to explain the proliferation of such views – information cascades and professional biases will do nicely.

Moreover, while no one I know doubts that externalities are real in the modern world, many of us doubt our ability to quantify them with any certainty or to remedy them through the political process in an efficiency-enhancing manner. One recent survey of the literature, for example, found that estimates regarding the externalities imposed by a ton of carbon emissions range from $9-200. If politicians were ever inclined to internalize those externalities through some set of public policies, the figure they would settle on would undoubtedly be driven more by politics than hard science or economics, which introduces the very real threat that they would make the economy more – not less – efficient as a consequence.