DAVID HANSON’s scientific contributions

The draft report issued last week by the U.S. Global Change Research Program—"Climate Change Impacts on the United States"—won't resolve controversies over human contributions to global climate change. This huge, profusely illustrated effort accepts that Earth is warming and devotes itself to describing potential impacts of this warming over the next 100 years. The study is unique in that it focuses on climatic changes in geographical regions, such as the South or Pacific Northwest, and impacts on "sectors," including water supplies, agriculture, forests, and human health. "Our work clearly indicates that climate change is a serious issue for the U.S.," says Anthony Janetos of the Washington, D.C.-based nonprofit World Resources Institute. Janetos was cochair of the team that did the analysis. "One of our most important findings is that in many cases regional- and local-level impacts are much more pronounced than those at the national level," says team cochair Thomas ...