Developing a rational, globally efficient time path for pricing or controlling greenhouse gas (GHG) emissions presents daunting challenges to policy makers, with large scientific uncertainties, and the absence of consensus over the long term goals of climate policies. In their article Climate Change and U.S. Interests, Jody Freeman and Andrew Guzman (FG) attempt to debunk what they label the “climate change winner” argument, i.e., the notion that the United States is likely to fare relatively well in a warmer world, at least compared to most other nations, and is thus not rationally compelled to invest in expensive mitigation efforts that may largely accrue to the benefit of others. Focusing on the integrated assessment models (IAMs), FG argue that the models are “methodologically limited in ways that systematically skew toward an understatement of . . . [damages].” Their conclusion: damage estimates derived from the IAMs are too low by an order or magnitude, not including a number of impact categories they are unable to quantify.