Former Vice President Al Gore (D) is not the only ex-politician who believes climate change is this generation’s chance to change the future.

In fact, a persistent group of former Members — who no longer have to worry about re-election and are free to work on issues they truly care about — are hard at work, both in the U.S. and in Copenhagen, trying to find a solution for climate change.

In the same way many of them are now focusing on climate change, so many originally tackled the subject during their Congressional tenures. The issue first gained traction more than 20 years ago, during the 1988 hearings remembered for the stark testimony of scientist James Hansen. Tim Wirth, then a Democratic Senator from Colorado and a member of the Energy and Natural Resources Committee, called the hearings, which brought global warming out of scientific journals and into public consciousness. Around the same time, major amendments to the Clean Air Act, which increased the federal government’s role in controlling air pollution, passed in 1990.

Wirth, who left the Senate in 1993, today leads the United Nations Foundation, a global nonprofit whose priorities include health care for women and children, sustainable development, and climate- and energy-related issues. The former Senator is attending the international climate summit in Copenhagen, which opened this week.

Climate change is “the most fascinating issue of them all, but it’s also the most important,— he said in a phone interview last week. “If we don’t act now, we will lose the opportunity forever.—

From early on, the issue attracted some bipartisan support. Former Rep. Sherwood Boehlert (R-N.Y.), who served from 1983 to 2007 and was chairman of the Science Committee, said he spoke to a number of Republicans about the climate change bill that passed the House earlier this year, including the eight who ultimately supported it. Boehlert said listening to “panel after panel, expert after expert— during his Congressional tenure convinced him of the validity of the global warming problem.

“Had I been there, I would have been on the floor, very vocal in support of— the bill, he said.

Since he left Congress, Boehlert has joined the boards of Al Gore’s Alliance for Climate Protection, the League of Conservation Voters and the Natural Resources Defense Council Action Fund.

The Energy Future Coalition, a domestic initiative co-founded by the U.N. Foundation that looks to bring together those interested in business, labor and the environment, recruited several former Members, both Democrats and Republicans, for its steering committee. Wirth said they bring a broad perspective and a sense of what it takes to get things done.

Former Rep. Vic Fazio (D-Calif.), a member of the steering committee and a lobbyist at Akin Gump Strauss Hauer & Feld, developed an interest in climate change during almost two decades on the Appropriations Subcommittee on Energy and Water. He agreed that former Members bring a unique perspective.

“I think they obviously became more internationally oriented during their service. I think a lot of them had committee assignments that would lead them to understand the energy picture better,— he said. “They’re citizens who pay attention to these matters, and they’re always going to be, to some degree, policy wonks.—

Former Sen. Steve Symms (R-Idaho), a lobbyist at Parry, Romani, DeConcini & Symms, also serves on the Energy Future Coalition’s steering committee. He remembers attending the U.N.’s first climate change conference in Rio de Janeiro in a delegation led by then-Sen. Al Gore (D-Tenn.) in 1992.

“I went because the administration at the time felt like they needed somebody down there that had more their perspective than anybody else in the delegation had,— he said. He spoke to attendees in Rio de Janeiro about the need for better design and technology.

He said he came aboard the Energy Future Coalition’s steering committee in order to bring balance, too, but noted that he’s interested in the business and economic implications of energy policy.

“We don’t all agree on everything, but whether you agree on climate change or not, there’s a good argument for trying to become less dependent on foreign sources of oil,— he said.