Int. J. Environ. Res. Public Health 2011, 8 1025 physical scientists who are either not sufficiently knowledgeable or have a prior bias towards particular physical science hypotheses or mitigation methods to the exclusion of others. What is needed on the part of economists is an inquiring and open mind, insistence on use of the most relevant observational data and the scientific method, and technical curiosity so as to determine whether there may be lower cost or more efficient alternative methods to achieve whatever the environmental control measures they are evaluating are supposed to achieve. Economists do not have to carry out the physical science research involved or invent the lower cost control measures, but they do need to recognize which research and control measures meet their needs in these respects and particularly which have been validated by use of the most relevant observational data and the scientific method. Acknowledgments References and Notes The author would like to acknowledge the many helpful comments of the anonymous peer reviewers and the original encouragement of Fred Singer to undertake an article on this topic. The views expressed in the article represent the views of the author alone, however. The permissions to use various figures received from their authors is also much appreciated. 1. Feynman, R. The Character of Natural Law; MIT Press: Cambridge, MA, USA, 1965; p. 156. 2. Crelinsten, J. Einstein’s Jury: The Race to Test Relativity; Princeton University Press: Princeton, NJ, USA, 2006. 3. Armstrong, J.S.; Green, K.C. Why the Global Warming Alarm Is an Anti-Scientific Political Movement. In Proceedings of the 4th Heartland Conference on Climate Change, Chicago, IL, USA, 18 May 2010; Available online: http://www.heartland.org/events/2010Chicago/ PowerPoints/Tuesday%20-%20Session%205/Track%204%20-%20Public%20Policy/J_Scott_ Armstrong.ppt (accessed on 21 December 2010). 4. Anagnostopoulos, G.G.; Koutsoyiannis, D.; Christofides, A.; Efstratiadis, A.; Mamassis, N. A comparison of local and aggregated climate model outputs with observed data. Hydrolog. Sci. J. 2010, 55, 1094-1110. 5. United Nations, Intergovernmental Panel on Climate Change. Fourth Assessment Report (AR4); Cambridge University Press: Cambridge, UK, 2007; Available online: http://www.ipcc.ch (accessed on 30 December 2010). 6. Idso, C.; Singer, S.F. Climate Change Reconsidered: The Report of the Nongovernmental International Panel on Climate Change; Heartland Institute: Chicago, IL, USA, 2009; Available online: http://www.nipccreport.org (accessed on 22 December 2010). 7. U.S. House of Representatives. H.R.2454: American Clean Energy and Security Act of 2009; Available online: http://thomas.loc.gov/cgi-bin/query/z?c111:H.R.2454 (accessed on 22 December 2010). 8. Segalstad, T.V. Geochemistry of CO2: The Whereabouts of CO2 on Earth. Presented at the Fourth International Conference on Climate Change, Chicago, IL, USA, 18 May 2010; Available online: http://www.heartland.org/events/2010Chicago/PowerPoints/Tuesday - Session 4/Track 1 - Science 1/Tom_Segalstad.pps (accessed on 22 December 2010)