The theory of resource extraction has focused primarily on extraction
when there is a single, homogeneous demand for the resource. In realit
y, however, we observe the simultaneous extraction of different resour
ces such as oil, coal, and natural gas and multiple demands such as tr
ansportation, residential and commercial heating, and electricity gene
ration. This paper develops a model with multiple resources and grades
and multiple demands. The model is simulated with extraction cost, es
timated reserves, and energy demand data for the world economy. It is
shown that if historical rates of cost reduction in the production of
solar energy are maintained, more than 90 percent of the world's coal
will never be used. The world will move from oil and natural gas use t
o solar energy. Global temperatures will rise by only about 1.5-2 degr
ees centigrade by the middle of the next century and then decline stea
dily to preindustrial levels, even without carbon taxes. These results
are significantly lower than those predicted by the Intergovernmental
Panel on Climate Change and suggest that the case for global warming
may be seriously overstated.