Reporting from Washington — The Obama administration pledged Thursday that the United States would cut its greenhouse gas emissions about 17% below 2005 levels by 2020 -- a step that would bolster the global warming deal brokered at climate talks last month.
In a letter to United Nations climate officials, the administration formally "associated" itself with the Copenhagen Accord by making the pledge, which it said would be outlined in more detail once Congress passes a bill limiting emissions.
Most of the world's largest emitters of greenhouse gases, which scientists blame for global warming, are expected to follow suit. Europe, Australia, Japan and other industrialized nations have said they will cut their emissions outright; fast-growing nations such as China and India say they will emit less as a share of their economies.
The Copenhagen deal gave countries until Jan. 31 to list targets and associate themselves with the accord, although U.N. officials said this month the date was flexible.
The accord is not legally binding, and it was not officially adopted by the 193 nations that gathered in Denmark in hopes of negotiating an agreement to replace the expiring Kyoto Protocol. It includes measures to verify that nations are meeting their targets, but no penalties for countries that fall short.
Tiny Marshall Islands signed on to the deal Thursday, pledging to cut emissions 40% by 2020 -- and calling on nations to immediately adopt a legally binding treaty.
"The Marshall Islands lies only two meters above sea level, and our narrow atoll islands have no high ground," Foreign Minister John Silk said in a statement. "We have the most to lose from a deadlock -- but we'll also suffer if there's a lowest-common-denominator agreement."
In his letter to the U.N., U.S. special climate envoy Todd Stern called the accord "an important step forward by the global community to address climate change and mitigate its impacts."
He said the 17%-range target, which Obama announced late last year, showed the president's "continued commitment to meeting the climate change and clean energy challenge through robust domestic and international action that will strengthen our economy, enhance our national security and protect our environment."
Stern did not say what would become of the pledge if Congress failed to pass climate legislation that includes an emissions cap. Such a bill passed the House in June, but its Senate prospects appear uncertain amid the fight over healthcare and Democrats' increasing nervousness about November elections.