Polls show that a majority of Americans support policies that would reduce greenhouse gases. But when it comes to paying for it, it's a different story.

Rep. John Dingell, D-Mich., wants to help cut consumption with a gas tax but some don't agree with the idea, according to a new poll by the National Center for Public Policy Research.

The poll, scheduled to be released on Thursday, shows 48 percent don't support paying even a penny more, 28 percent would pay up to 50 cents more, 10 percent would pay more than 50 cents and 8 percent would pay more than a dollar.

Some environmentalists and economists say pain at the pump may be bad for Americans, but good medicine for a sick planet.

But others say it wouldn't change much. Even if Americans abandoned their cars, global emissions would fall by less than one percent.