Computerized models of the earth's climate are at
the heart of the debate over how policy should respond to climate
change. Global climate models (GCMs)--also called general
circulation models -- attempt to predict future climatic
conditions starting with a set of assumptions about how the
climate works and guesses about what a future world might look
like in terms of population, energy use, technological
development, and so on.
Analysts have pointed out, however, that many of the assumptions
used in modeling the climate are of dubious merit, with biases
that tend to project catastrophic warming, and have argued that
climate models have many limitations that make them unsuitable as
the basis for developing public policy. This paper examines two
major limitations that hinder the usefullness of climate models
to those forming public policy.