Does a consensus of economists carry the same weight as a consensus of climate scientists?

Useful article & also Robert Stavins' article - thanks. Please help me eliminate a certain worry... 1) I've studied the Stern Review, the Nordhaus DICE model, MIT model, the economic assumptions by IPCC, the EDF work. There is indeed seems a consensus as you describe (good), even as people argue about discount rates, pricing mechanisms, etc. 2) There also seems a consensus that we should expect indefinite economic growth, at rates akin to that seen for the last century., adn that's the part that worries me. I undersand the following is a minority position amongst economists, but I worry that folks like Robert Ayres and Benjamin Warr may well be right, i.e., that a big chunk of the last century's economic growth came from cheap energy. More precisely, they claim that "Total factor Productivity" or "Technology Progress" or "The Solow Residual" are mostly due to: work = energy * efficiency http://www.iea.org/Textbase/work/2004/eewp/Ayres-paper1.pdf http://www.cge.uevora.pt/aspo2005/abscom/ASPO2005_Ayres.pdf (See the last page for models of the US economy under various efficiency assumptions). I've also reviewed a forthcoming book of theirs, and it seems persuasive, but then I'm no economist. People like Charlie Hall seem compelling that we've been using up the high Energy Return on Energy Invested (EROEI) fuels, and that we have a long way to go to replace fossil fuels. See balloon chart in: http://www.theoildrum.com/node/3949 Peak Gas seems likely a few decades away, but Peak Oil is certainly coming within the next decade, if not already, and supply constraints tend to create price instabilities. People are arguing about the actual coal supply, but of course, if we have to use more coal to make up for downturns in the others, that's real climate trouble. If those arguments are believable, then it isn't a question of discount rates and ~1% cost, it's a question of not driving the economy off the energy cliff. From business experience, I observe that companies (especially high-tech ones with fast product cycles) have to invest profits from a current product line (that is going to go away) into the next product line, and do it while they still have capital, else they get downsized. Put another way, if you believe these folks, we should be doing everything possible on energy efficiency, building sustainable supplies, and stretching oil+gas as long as we can [all for economics] and lessening coal [for climate.] In this case, it would seem that the long-term costs are actually negative, i.e., they keep a potential economic downturn over the next few decades from being worse. 3) I'd love to have someone reassure me that there is something fundamentally wrong with 2), that economic growth can ignore Peak Oil (and later Peak Gas). I've been asking around, but so far, haven't found any strong reassurance. For example: April 18, 2008: http://johnquiggin.com/index.php/archives/2008/04/18/guest-post-from-joh... May 12, 2008 http://blogs.edf.org/climate411/2008/04/30/economic_models/ May 20, 2008: http://www.econbrowser.com/archives/2008/05/oil_price_funda.html Anyway, any pointers to further my understanding would be very helpful. ===== Notes on your article: a) Lomborg is a political scientist, and it's unclear how much real statistics he does, but he's a very clever political advocate, as the Copenhagen Consensus manages to confuse many people: http://thingsbreak.wordpress.com/2009/01/08/lomborg-long-game/ b) You probably know this, but if not, Margo Thorning is also one of the Heartland Institute's climate experts: http://www.globalwarmingheartland.org/experts.html c) Minor nit: footnote 40 gives a date for Holdren's article as August 4, 2009, but as noted, data from the future is not usually available.

Eric, This is an interesting article. I'd like to add one comment and one clarification, if you don't mind. First, my comment. I believe that the reason why journalists have not emphasized the degree of agreement among economists on this topic is simply an example of a much broader phenomenon. On many or most issues -- not only in economics, let alone only in environmental economics -- there is a distribution of views among experts -- pictured a nice, bell-shaped distribution. Ninety-five percent or more of the experts have similar views, but at the two extremes of the distribution are the outliers, the two-and-a-half percent at both ends of the distribution who represent the most extreme views. These may often be representatives of interest groups. In the environmental sphere, think of the representative from the national association of manufacturers and the representative from Greenpeace. The journalist covering the story wants to "bracket the truth" to avoid bias in her article, so she includes quotes from these two. Also, it makes for vastly more drama in the story. The 95 percent of us who are middle-of-the-roaders (which economists tend to be, because of our focus on balancing benefits and costs of any kind of policy question) don't make for useful quotes: "Well, on the one hand, ...., but, on the other hand..." You remember Harry Truman's lament that he wanted to meet a one-handed economist. So, I see the phenomenon you've identified as a special case of a much broader reality. Second, the clarification. I'm sure I did not use the words that I "can't stand Stern's methodology." You don't offer it as a direct quote, but some readers might get the wrong impression. What I would say is that a broad cross-section of environmental and energy economists have been critical of particular dimensions of the methodology in the Stern Review. Indeed, an academic journal of which I'm the editor, The Review of Environmental Economics and Policy (Oxford University Press) published a symposium of critiques by economists from Stanford, Yale, and elsewhere, plus a comprehensive response by Nick Stern and his co-author, Simon Dietz, in the Winter 2008 issue. In two subsequent issues, the exchanges continued. Thanks again for a very interesting article. Best wishes, Rob