| Abstract: |
In 2007, the Intergovernmental Panel on Climate Change’s Working Group One, a
panel of experts established by the World Meteorological Organization and the
United Nations Environment Programme, issued its Fourth Assessment Report. The
Report included predictions of dramatic increases in average world
temperatures over the next 92 years and serious harm resulting from the
predicted temperature increases. Using forecasting principles as our guide we
asked: Are these forecasts a good basis for developing public policy? Our
answer is “no.” To provide forecasts of climate change that are useful for
policy-making, one would need to forecast (1) global temperature, (2) the
effects of any temperature changes, (3) the effects of alternative policies,
and (4) whether the best policy would be successfully implemented. Proper
forecasts of all four are necessary for rational policy making. The IPCC
Report was regarded as providing the most credible long-term forecasts of
global average temperatures by 31 of the 51 scientists and others involved in
forecasting climate change who responded to our survey. We found no references
to the primary sources of information on forecasting methods despite the fact
these are easily available in books, articles, and websites. We audited the
forecasting processes described in Chapter 8 of the IPCC’s WG1 Report to
assess the extent to which they complied with forecasting principles. We found
enough information to make judgments on 89 out of a total of 140 forecasting
principles. The forecasting procedures that were described violated 72
principles. Many of the violations were, by themselves, critical. The
forecasts in the Report were not the outcome of scientific procedures. In
effect, they were the opinions of scientists transformed by mathematics and
obscured by complex writing. Research on forecasting has shown that experts’
predictions are not useful. We have been unable to identify any scientific
forecasts of global warming. Claims that the Earth will get warmer have no
more credence than saying that it will get colder. |