Bjorn Lomborg ("Can Anything Serious Happen in Cancun?
", op-ed, Nov. 12) claims that government spending on global warming policies is wasted, but he assumes that global warming caused by carbon dioxide is a fact. It is not. We base this statement not on the opinions of 31,000 American scientists who signed a public statement rejecting this warming hypothesis (the "Oregon Petition"), but rather because the forecasts of global warming were derived from faulty procedures.
We published a peer-reviewed paper showing that the forecasting procedures used by the U.N.'s Intergovernmental Panel on Climate Change violated 72 of 89 relevant principles (e.g., "provide full disclosure of methods"). The IPCC has been unable to explain why it violated such principles. In response, we developed a model that follows the principles. Because the climate is complex and poorly understood, our model predicts that global average temperatures will not change.
In testing the models on global temperature data since 1850, we found that the long-range (91-to-100-years ahead) forecast errors from the IPCC's projection were 12 times larger than the errors from our simple model.
Mr. Lomborg concludes there are better ways for governments to spend the funds devoted to global warming. We suggest this money should instead be returned to taxpayers.
J. Scott Armstrong
The Wharton School
University of Pennsylvania