Senator Lamar Alexander (R-TN) – Sits on the Senate Environment and Public Works Committee; has stated that global warming is a threat; is a cosponsor of the Carper-Alexander Clean Air Planning Act that, among other things, would cap global warming pollution from America's power plants.

Senator Jeff Bingaman (D-NM) – Chair of the Senate Energy and Natural Resources Committee; last year worked with fellow New Mexico Senator Pete Domenici to circulate a white paper on global warming solutions and to organize a Climate Conference at which business leaders from leading industries spoke out in favor of national action; has proposed his own legislative compromise that falls short of setting a nation-wide hard cap.

Senator Barbara Boxer (D-CA) – Chair of the Senate Environment and Public Works Committee; has pledged to hold a series of hearings early this year on global warming solutions; is cosponsor of the Sanders-Boxer Global Warming Pollution Reduction Act, which calls for America to cut its global warming pollution by 80% below 1990 levels by 2050.

Senator Tom Carper (D-DE) – Cosponsor of the Carper-Alexander Clean Air Planning Act that would cap global warming pollution from America's power plants; also supports economy-wide global warming cap and trade legislation; is the Chair of the Clean Air Act Subcommittee of the Senate's Environment and Public Works Committee.

Senator Pete Domenici (R-NM) – Ranking member and former chair of the Senate Energy and Natural Resources Committee; has served in the Senate for 35 years and is a widely respected Senate leader; last year, worked with fellow New Mexico Senator Jeff Bingaman to organize a white paper and a Climate Conference to examine global warming solutions.

Senator James Inhofe (R-OK) – Comes from an oil state; one of the most vocal global warming skeptics on the Hill; has called global warming the greatest hoax ever perpetrated on mankind; as former chair of the Senate Environment and Public Works Committee, can be counted on to use his experience and knowledge of Senate rules to block action.

Senator Joe Lieberman (I-CT) – Cosponsor of the Lieberman-McCain Climate Stewardship and Innovation Act, the first global warming bill to establish an economy-wide cap on global warming pollution; chair of the Private Sector and Consumer Solutions to Global Warming and Wildlife Protection Subcommittee under the Environment and Public Works Committee.

Senator John McCain (R-AZ) – Cosponsor of the Lieberman-McCain Climate Stewardship and Innovation Act; has been a vocal leader on the need for global warming action; has led trips to the Arctic and Norway with his Senate colleagues to highlight the impacts of global warming.

Senator Bernie Sanders (I-VT) – Freshman senator; replaced retired Senator Jim Jeffords; sits on both the Senate's Environment and Public Works Committee and the Energy and Natural Resources Committee; is cosponsor of the Sanders-Boxer Global Warming Pollution Reduction Act, which calls for America to cut its global warming pollution by 80% below 1990 levels by 2050.

Senator John Warner (R-VA) – Influential Senate leader who has served since 1979; sits on the Senate Environment and Public Works Committee; has voted against legislation that would cap America's global warming pollution, but has also voted for a nonbinding Sense of the Senate resolution in 2005 that called for meaningful action; has said he agrees "with the majority of climate experts that human activity is the root cause of today's global warming."