Why is there still so much uncertainty in certain areas of science, such as climate change research?
I like to point out that the uncertainties in projections about future climate are not so much uncertainties about climate science; they’re uncertainties about social science. For example, the range of outcomes depends on projections of how many people will be living on Earth in the 21st century, and demographic projections are tough business. In the 20th century, we went through a period of exponential growth, with populations doubling every 30 to 40 years. By the end of the 20th century, that rate of growth had slowed somewhat. With projections for the 21st century, the United Nations now has a high projection, a medium projection and a low projection, depending upon certain social factors playing out. One of them has to do with education—birth rates are very clearly correlated with the educational level of women. The question is, how much education will we have for women worldwide in the 21st century? These are social science issues, not climate science issues. Another question that
