Correction Appended

A scientist who has long disagreed with the dominant view that global warming stems mainly from human activity has resigned from a panel that is completing a report for the Bush administration on temperature trends in the atmosphere.

The scientist, Roger A. Pielke Sr., a climatologist at Colorado State University, said most of the other scientists working on the report were too deeply wedded to particular views and were discounting minority opinions on the quality of climate records and possible causes of warming.

"When you appoint people to a committee who are experts in an area but evaluating their own work," he said in an interview, "it's very difficult for them to think outside the box of their research."

Administration officials said the resignation would not affect the quality or credibility of the report, a draft of which is being finished in the next few weeks.