Perspectives on future climate change highlight two truisms: 1) given the known greenhouse properties of CO2, its anthropogenic increase in the atmosphere is bound to influence global temperatures to some extent; and 2) the magnitude of the effect is uncertain because global climate models are imperfect.

However, consideration of data internal to the Intergovernmental Panel on Climate Change (IPCC) scientific assessment [Houghton et al., 1990] suggests that there is less uncertainty than current debates assume. I argue here that the high-end estimate of future global temperature is unlikely, and that grassroots appeal to national economic interests might prove more effective in meeting the actual level of threat than coercive international regulations imposed in a topdown mode.