But quietly, many acknowledge a deepening GOP schism over the issue, as many moderates grow increasingly disturbed by their party's denial of proven science. A number of influential Republicans who have left the battlefield of electoral politics are now taking action in an effort to change the GOP's stance.

Conservative economist Douglas Holtz-Eakin, a senior advisor on McCain's 2008 presidential campaign who now heads the center-right think tank American Action Forum, is working with the New Hampshire-based climate policy advocacy group Clean Air-Cool Planet. The group has flown Holtz-Eakin to the state several times over the last few months to hold small living-room meetings to talk to voters about the economic concerns raised by climate change--and the economic benefits of addressing the problem.

Holtz-Eakin said he's not trying to evangelize about climate science, but is presenting the case for policies that could address the problem in a way that benefits the economy. One proposal that has long been embraced by conservative economists, for example, is a tax swap--imposing a tax on carbon emissions, while eliminating the payroll tax.

Environmentalists believe that the underlying message of such talks could resonate powerfully in New Hampshire, a key presidential primary state.

"Our objective is to make sure that when candidates come to New Hampshire it's not adequate to come dismiss the science and write this off," said Brooks Yeager, executive vice president of policy for Clean Air-Cool Planet, referring specifically to Texas Gov. Perry's public rejections of climate science.

"We have watched with foreboding as powerful forces in the Republican Party want to close down this debate and reject the idea that this is a problem that needs to be solved," Yeager said. "Our interest in working with someone like Douglas, who has enormous credibility in conservative ranks and economists and agrees with our fundamental position that this is a problem that needs to be solved, is that he is exceptionally well positioned to reopen this debate."

Respected elder statesmen of the GOP also are using their clout to send a message on climate. John Warner, the former Virginia senator who now lobbies with the firm Hogan Lovells, is also a senior adviser to the Pew Project on National Security, Energy, and Climate Change, which focuses on the need to develop alternative energy to combat climate change and lessen dependence on foreign oil.

Warner, who in 2007 cosponsored a sweeping climate-change bill with then-Democrat and now independent Sen. Joseph I. Lieberman of Connecticut, recalled proudly that his cap-and-trade bill got further in the Senate than any climate legislation before or since.

"Factually, that is the only comprehensive clean-energy bill that got to the Senate floor, and nothing's happened since," Warner said.