July 4, 2003

Abrupt Changes in Climate

To the Editor:

The article by Richard Monastersky on abrupt climate change examines an important scientific topic that deserves public attention ("Hot Air and Cold Fear," May 23). The reporter makes clear that large uncertainties and disagreements exist within the research community about if, where, and when such change might occur. The article questions why I chose to use a particular climate-change simulation and not others, so I seek to respond.

Global-climate models are