The bill, which had bipartisan support but not enough to overcome opposition, aimed to cut total U.S. global warming emissions by 66 percent by 2050. Opponents said it would cost jobs and raise fuel prices in an already pinched American economy.
Known as the Lieberman-Warner Climate Security Act, the bill's chances of passage were always slim. Even if Congress had approved it, President George W. Bush had vowed a veto.
Bush has consistently opposed any economy-wide program to curb the carbon dioxide emissions that spur climate change, arguing that this would hurt the U.S. economy.
U.S. greenhouse gas emissions would drop by about 2 percent per year between 2012 and 2050, based on 2005 emission levels, under a summary of the measure by its Senate supporters.
Carbon dioxide, which contributes to the climate-warming greenhouse effect, is emitted by fossil-fueled vehicles, coal-fired power plants and natural sources, including human breath.
Senators John McCain and Barack Obama, the respective Republican and Democratic presidential nominees, were not present for the vote, but both support limiting human-generated emissions that spur climate change.