Overlooked issues in the U.S. national climate and IPCC assessments

nonlinear. As a result the prediction of fRecent research has identified several scientific issues that have not been adequately considered in either the U.S. National Climate Assessment or the IPCC Reports. These include: (i) the effect of land use change on regional and the global energy and moisture budgets; and (ii) the effect on weather of combined biophysical and biogeochemical processes. These effects exert direct influences on the net radiation received at the Earth's surface and through the troposphere, as well as produce complex nonlinear feedbacks between the atmosphere and the surface. Using global and regional modeling results, examples of these effects will be presented at the meeting. Included will be results from coupled atmospheric-land surface process modeling.

A conclusion of the research is that there are several significant anthropogenic effects on the Earth's climate system, and that feedbacks between components of the Earth's climate system are complex and nonlinear. As a result the prediction of future climate is a difficult if not impossible task. As an alternative, this paper proposes a vulnerability assessment approac