WASHINGTON — Global warming isn’t to blame for the recent jump in hurricanes in the Atlantic, concludes a study by a prominent federal scientist whose position has shifted on the subject.

Also, warmer temperatures will actually reduce the number of hurricanes in the Atlantic and those making landfall, research meteorologist Tom Knutson reported in a study released yesterday.

In the past, Mr. Knutson has raised concerns about the effects of climate change on storms. His new paper has the potential to heat up a simmering debate among meteorologists about current and future effects of global warming in the Atlantic.

Ever since Hurricane Katrina in 2005, hurricanes have often been seen as a symbol of global warming’s wrath. Many climate change experts have tied the rise of hurricanes in recent years to global warming and hotter waters that fuel them.

Another group of experts, those who study hurricanes and who are more often skeptical about global warming, say there is no link. They attribute the recent increase to a natural multi-decade cycle. What makes this study different is Mr. Knutson, a meteorologist with the National Oceanic and Atmospheric Administration’s fluid dynamics lab. He has warned about the harmful effects of climate change and has even complained in the past about being censored by the Bush administration on past studies on the dangers of global warming.