Global warming debate guided by politicians.

• Position: You Life

More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of global warming, according to research published in Climate Change. In a study of public opinion from 2002 to 2010, it was found that public belief that climate change was a threat peaked in 2006-07 when Democrats and Republicans in Congress showed the most agreement on the issue. Yet, public concern has dropped since then, as partisanship over the issue increased.

"It is the political leaders in Washington who are really driving public opinion about the threat of climate change," says study coauthor J. Craig Jenkins. "The politics overwhelms the science."

The study found that the incidence of extreme weather events has no effect on Americans' views of the climate change threat. New research published in scientific journals have no impact on public views, but major reports on climate change and articles in popular science magazines do have a small impact. The work of advocacy groups also has some effect. The state of the economy is the second biggest factor affecting perceptions of climate threat. The quantity of media coverage also affects perceived threat levels, but that coverage mostly is a...