Before the anticlimactic demise on Friday of legislation to combat global warming, the Senate majority leader, Harry Reid, Democrat of Nevada, called climate change "the most important issue facing the world today.' Senator George V. Voinovich, Republican of Ohio, a critic of the bill, nonetheless called it "the most significant piece of legislation to ever come out of the Environment and Public Works Committee.' Senator John W. Warner winked at Senator Joseph I. Lieberman as he was met by Senators John Kerry, left, and Barbara Boxer. Senator Barbara Boxer, Democrat of California, said the effort to limit heat-trapping gases was "one of the greatest challenges of our generation.' Senator Barack Obama of Illinois, the presumptive Democratic presidential nominee, said in a statement, "The future of our planet is at stake.' And even Senator James M. Inhofe, Republican of Oklahoma, the leading opponent of the legislation, called it "probably the largest bill ever considered by the Senate in its impact on the economy and our way of life.' And so it was, with a chorus of Senate voices having proclaimed the urgency and importance of the issue that the Great Climate Change Debate of 2008 ended on Friday morning, after three and a half days, with a procedural vote that effectively shelved the bill until next year. A motion by Democrats to end debate and move to a final vote, requiring 60 votes to succeed, fell far short, with 48 senators in favor and 36 against. The bill would cap the production of heat-trapping gases and force polluters to buy permits to emit carbon dioxide. Critics, including many Republican senators, said it would raise energy prices, including the cost of oil, at a time when Americans are struggling with record gasoline prices. But there were also critics at the other end of the political spectrum who said the bill's limits on carbon emissions were not strict enough. They said the legislation would allow some industries to prosper while forcing average Americans to pay higher energy prices. The result left lawmakers pointing fingers at one another. Democrats said Republicans had obstructed their efforts to address a most crucial issue, while Republicans said the Democrats were never serious about passing the bill, as evidenced by their unwillingness to allow a serious and lengthy debate over amendments. Environmental groups, meanwhile, were left struggling to read the tea leaves of yet another procedural step by the Senate, which has been called the world's greatest deliberative body but can also be its most mercurial and maddening. In a speech on the Senate floor on Thursday, the Republican leader, Mitch McConnell of Kentucky, mocked the Democrats as trumpeting the magnitude of the climate change but then seeking to cut off debate and move swiftly to a final vote. "What are they afraid of?' Mr. McConnell asked. "Why don't they want to consider amendments to a bill addressing what they call