Over the past century, the Earth's surface temperature has risen by about 1 degree Fahrenheit. The primary cause of global warming is increased emissions of carbon dioxide and other greenhouse gases, which threaten to raise sea levels, trigger extended heat waves, exacerbate hurricane seasons, and destroy habitat and species. As a result, environmentalists overwhelmingly support mandatory limits on global warming pollution from power plants, factories, vehicles, and other sources.

On June 22, 2005, the Senate for the first time endorsed such limits by adopting a "Sense of the Senate" resolution offered by Senators Jeff Bingaman (D-NM) and Arlen Specter (R-PA). This watershed vote puts the Senate on record that global warming is real and that mandatory limits are necessary to slow, stop, and reverse the growth of global warming pollution. Before the resolution passed by voice vote, Senator James Inhofe (R-OK) offered a motion to table (kill) Senate Amendment 866. By a 44-53 vote, the Senate rejected the motion (Senate roll call vote 149). NO is the pro-environment vote.