A key U.S. Senate environment committee approved a Democratic climate change bill today that would require industry to cut emissions of carbon dioxide and other greenhouse gases 20 percent by 2020 from 2005 levels, dpa reported. The bill approved by the Environment and Public Works Committee will now become one of several initiatives in the Senate aimed at attacking global warming. But they are unlikely to produce legislation that would be voted on by the full Senate until next year at the earliest. With Republicans boycotting the environment panel"s measure, saying more analysis of the legislation was needed, 10 Democrats approved the bill and one Democrat, Senator Max Baucus, voted against it. Senator John Kerry, who co-authored the bill with fellow Democrat Barbara Boxer, is leading an effort with some Republicans and the White House to draft a compromise. Democrats in Congress, working on a major plank of President Barack Obama"s agenda, have been anxious to show at least some progress on enacting a domestic climate change bill before Dec. 7, when an international global warming summit convenes in Copenhagen. While there were scores of amendments to the bill that environment committee members wanted to debate and vote on before approving it, they were unable to because of the Republican boycott. Under committee rules, at least two Republicans had to be present to debate and vote on changing the bill. Boxer delayed work on the legislation for two days, saying she was giving Republicans the opportunity to collect more information from EPA officials and to offer their own amendments. But Republicans did not take her up on the offer and by Thursday, Boxer had lost patience with the delay. She opened Thursday"s work session reading from a letter from John Rowe, Chief Executive of Exelon, one of the country"s largest utilities. Calling the bill written by Boxer and Kerry "an excellent starting point," Rowe wrote, "We urge you as chairman, as well as your colleagues, to take the steps necessary to order the bill reported by the committee so that climate legislation can be considered by the full Senate." Baucus" vote against the bill reflected the difficulties ahead in crafting a measure that would attract the 60 votes needed for passage by the Senate. As an influential moderate Democrat, Baucus laid out changes he would seek, including a weaker carbon-reduction target. Other Midwestern and Southern senators from states heavily reliant on coal will seek their own changes, which could upset liberals now supporting the bill.