Int. J. Environ. Res. Public Health 2011, 8 1019 Table 3. Some previous estimates of the economic benefits of climate change control. Warming (oC) 3.0 3.0 2.5 2.5 2.5 2.5 2.5 Study Nordhaus (1994) [66] Nordhaus (1994) [67] Fankhauser (1995) [68] Tol (1995) [69] Nordhaus and Yanga (1996) [70] Plamberk and Hopea (1996) [71] Mendelsohn et al.a,b,c (2000) [72] Impact (%GDP) –1.3 –4.8 (–30 to 0) –1.4 –1.9 –1.7 –2.5 (–0.5 to –11.4) 0.0b 0.1b Nordhaus and Boyer (2000) [73] 2.5 –1.5 Tol (2002a) [74] 1.0 2.3 Maddison (2003) a,d,e [75] 2.5 –0.1 Rehdanz and Maddisona,c (2005) [76] 1.0 –0.4 Hope (2006) a,f [77] 2.5 0.9 (–0.2 to 2.7) Nordhaus (2006) [78] 2.5 –0.9 (0.1) Stern (2006) [63] –5 to as much as –20% Garnaut (2008) [64] 5.1 Krugman (2010) [65] (5.0) g (–5) g Sources: Tol [54] summary for first 13 studies. Fragmentary data for last three based on this author‘s reading of these studies. Notes on Table: a. The global results were aggregated by Tol [54]. b. The top estimate is for the ―experimental‖ model, the bottom estimate for the ―cross-sectional‖ model. c. Mendelsohn et al. only include market impacts. d. The national results were aggregated to regions by the current author for reasons of comparability. e. Maddison only considers market impacts on households. f. The numbers used by Hope are averages of previous estimates by Fankhauser and Tol; Stern et al. (2006) [63] adopted the work of Hope. g. Krugman does not explicitly endorse these figures but rather speaks highly of them on pdf page 8. 5.1. Krugman Paul Krugman is arguably one of the more influential American economists given his long-running column in the New York Times. In 2010 he wrote an extensive summary of global climate economics for the New York Times Magazine [65]. Although not in academic format it is probably one of the most widely read articles on the subject to date. So it is worth examining it in some detail for the insight it may provide on economists‘ use of physical science information and the influence this has on the conclusions reached. Krugman‘s analysis [65] has a brief three-paragraph summary of his understanding of the physical science aspects. This is unusual and worthy of note since many other economists have either not tried to understand the physical science aspects or at least not reported having tried to do so. So he deserves credit for recognizing the importance of these aspects. He did not provide (reasonably, given the magazine format), however, citations for his viewpoints, so it is unclear where he obtained his views. These views, however, do not ask the crucial questions concerning the consistency of the science with the scientific method emphasized in this article, but are nevertheless important to understanding his argument so are worthy of detailed analysis. His basic points [65] were as follows: