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 industrialized and developing 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.
This is a new goal and "the clearest signal yet that China is willing to take on responsibilities that are commensurate with its resources and global emissions impact," said Julian L. Wong, a senior policy analyst at the Center for American Progress, a nonpartisan research institution that supports Obama's initiatives.
Wong said that Hu's statement commits China to measuring its carbon emissions for the first time, but whether it opens this process to international verification remains to be seen.
Hu's statement followed other policy actions by China's leadership in recent years that reduce the rate of increase of the country's emissions.
"Quite frankly, China is making great strides in many areas," Energy Secretary Steven Chu said in an interview Tuesday with McClatchy.
Chu said it was possible to keep temperatures from rising beyond 3.5 degrees Fahrenheit, the level that world leaders and scientists have agreed shouldn't be crossed.
"This goal, which is an ambitious goal, is achievable, but we'll have to work very hard to get there," he said. "Having said all that, the thing we've got to do is get started. We've got to realize the dangers of what would happen" if temperatures increase by 11 degrees Fahrenheit or more, as scientific studies have shown could happen if no limits are put on emissions.
"At all costs we want to avoid entering into that region, because it would be a very different world," Chu said.
China, India and other large developing countries have said that it's impossible for them to put a binding cap on emissions.
India announced last week that it would make voluntary emission cuts through greater efficiency and more use of renewable energy.
Hu said that China would improve energy efficiency and conservation. He repeated a Chinese promise to make non-fossil-fuel energy — renewable energy and nuclear energy — 15 percent of its electricity production by 2020. He promised that China would continue its drive to replant forests so that it would have nearly 99 million acres of forests, which absorb some greenhouse gas emissions, by 2020. He also said that China would increase research and development of clean energy.
Todd Stern, the U.S. special envoy for climate change, said Obama's proposals would mean "seismic change" in American energy policy, and he suggested that Europeans weren't giving him enough credit.
Stern acknowledged that a completed agreement is unlikely in Copenhagen and that under the best scenario, there'll be numerous details to wrap up afterward. "That's always been the understanding," he said.
MORE FROM MCCLATCHY