UNITED NATIONS — Presidents Barack Obama and Hu Jintao of China —the leaders of the two countries that emit the most greenhouse gases — pledged at a United Nations summit Tuesday that their countries would take bold actions to protect the Earth's future climate from irreversible damages.
Obama and Hu listed what their countries already have done to reduce emissions of heat-trapping gases and acknowledged that much more would be needed, although they didn't specify what new steps lie ahead.
U.N. General-Secretary Ban Ki-moon opened the special climate session with an appeal to all countries to work toward "a common, long-term goal to limit global temperatures to safe levels consistent with science."
Negotiations for a climate agreement in Copenhagen, Denmark, in December have been bogged down as countries argue about which should act first, and how much they should cut emissions. The goal in Copenhagen is for industrialized countries to set midterm and long-term limits on carbon pollution and for developing countries to declare what steps they'll take to reduce emissions, a step short of making mandatory reductions.
Another area of dispute is how much the world's wealthy nations will pay to help poorer ones reduce emissions and adapt to unavoidable climate change. Any general agreement probably would require more work after the Copenhagen talks to fill in details.
"Success in Copenhagen will have positive ripple effects for global cooperation on trade, energy, security and health," Ban said. "Failure to reach broad agreement in Copenhagen would be morally inexcusable, economically shortsighted and politically unwise."
Obama warned that unless the world's nations act "boldly, swiftly and together, we risk consigning future generations to an irreversible catastrophe." He added, "No nation, however large or small, wealthy or poor, can escape the impact of climate change," which includes rising seas, more frequent droughts and more powerful storms and floods.
Obama announced that at the Group of 20 meeting Thursday in Pittsburgh he'd propose phasing out fossil fuel subsidies so that money can be directed to climate protection.
The United States has been the subject of increasing complaints from Europe for not doing more to set strict limits on carbon emissions.
In his speech, Obama said that since he took office in January, "The United States has done more to promote clean energy and reduce carbon pollution in the last eight months than at any other time in our history."
Energy and climate legislation is moving slowly in Congress, however, taking a back seat to Obama's priority of health care restructuring.
China's Hu said his country would cut carbon dioxide emissions as a percentage of economic output by a "notable margin" by 2020, but he didn't specify an amount. China's overall emissions are expected to keep growing through this period.