Global warming, that is. Which is to say that the projections concerning global warming are based in large part on assumptions about trends in industrial activity and other human activites that generate greenhouse gasses. These assumptions are based in economic predictions. It turns out these assumptions are seriously flawed in that they grossly over-estimate future green house gas production.
Anyone puzzled by the science behind Kyoto should take a look at the economics. In the words of one leading economic modeller, the central 100-year economic projections behind Kyoto and global warming policymaking is an "insult to science" and "an insult to serious analysis." And that's probably the good part of any criticism. It is also clear that the economic work of the Intergovernmental Panel on Climate Change (IPCC) is driven by systemic ideological preferences for state intervention.
A vocal group of economists around the world -- including some of the leading figures in the field of global economic modelling -- believe the core economic analysis behind the United Nations climate change initiative is based on seriously flawed modelling principles. If their analysis is correct, the central scientific tenets of global warming, including 100-year carbon emissions forecasts and temperature increases, are likely grossly exaggerated.