WASHINGTON  The problem with global warming, some environmentalists believe, is “global warming.”

The term turns people off, fostering images of shaggy-haired liberals, economic sacrifice and complex scientific disputes, according to extensive polling and focus group sessions conducted by ecoAmerica, a nonprofit environmental marketing and messaging firm in Washington.

Instead of grim warnings about global warming, the firm advises, talk about “our deteriorating atmosphere.” Drop discussions of carbon dioxide and bring up “moving away from the dirty fuels of the past.” Don’t confuse people with cap and trade; use terms like “cap and cash back” or “pollution reduction refund.”

EcoAmerica has been conducting research for the last several years to find new ways to frame environmental issues and so build public support for climate change legislation and other initiatives. A summary of the group’s latest findings and recommendations was accidentally sent by e-mail to a number of news organizations by someone who sat in this week on a briefing intended for government officials and environmental leaders.

Asked about the summary, ecoAmerica’s president and founder, Robert M. Perkowitz, requested that it not be reported until the formal release of the firm’s full paper later this month, but acknowledged that its wide distribution now made compliance with his request unlikely.