The fate of U.S. legislation capping carbon emissions weighed heavily on delegates at U.N. climate talks starting Monday in Bangkok, with the Americans saying delays in passing the bill could deter commitments from other nations.
Negotiations on a new U.N. climate pact have been bogged down by a broad unwillingness to commit to firm emissions targets, and a refusal by developing countries to sign a deal until the West guarantees tens of billions of dollars in financial assistance — something rich countries have so far refused to do.
"The more specific we can be, the easier it is to press others to be equally specific," Jonathan Pershing, the chief U.S. negotiator at the talks, told The Associated Press. "We have a lot of things we want from countries. ... The less we can put on the table, the harder it is to achieve that outcome."
The two weeks of U.N. climate talks in the Thai capital are drawing some 1,500 delegates from 180 countries to boil down a 200-page draft agreement to something more manageable, aiming for a new international climate pact this year.
In June, the U.S. House of Representatives passed its first bill to cap carbon emissions. The Senate, currently embroiled in debate on health care, is expected to take up the legislation as early as this week.
But Pershing said he doubted there's enough time to pass a climate bill in Congress before the year's biggest climate change negotiations in Copenhagen in December, which aims to reach a deal to replace the Kyoto Protocol expiring in 2012.
He said it wouldn't prevent a global deal as long as "we have clear movement, clear intent and a signal from the Senate that is it is moving" toward passage.
U.N. climate chief Yvo de Boer warned that the U.S. should not repeat what happened with the 1997 Kyoto agreement, when it signed on to the deal only to have Congress reject it a few years later, over concerns it would hurt the economy and failed to require China and India to curb their emissions.
President Barack Obama and Chinese President Hu Jintao — whose countries are the world's two biggest emitters, each accounting for about 20 percent of greenhouse gas pollution — both vowed tough measures to combat climate change at U.N. talks in New York last week.
Hu said China would generate 15 percent of its energy from renewable sources within a decade, and for the first time pledged to reduce the rate by which its carbon emissions rise. He did not give specific targets.
Japan's new prime minister, Yukio Hatoyama, whose nation generates more than 4 percent of the world's greenhouse gases, pledged to seek a 25 percent cut in emissions from 1990 levels by 2020.
Most countries agree that temperature increases should be limited to 3.6 degrees Fahrenheit (2 degrees Celsius) above preindustrial levels of about 150 years ago — a level believed necessary to avoid the worst impacts of climate change.
Most industrialized nations have offered emissions cuts of 15 percent to 23 percent below 1990 levels by 2020, falling short of the 25 percent to 40 percent cuts scientists and activists say are needed to keep temperature increases below 3.6 degrees Fahrenheit (2 degrees Celsius).
The United States has offered much lower targets so far, with the House bill proposing to reduce emissions by 17 percent from 2005 levels — that is about 4 percent below 1990 levels — by 2020.
There will be one more meeting in Spain in November before negotiators head to Copenhagen. De Boer said negotiations were far behind where they should be, but remained confident a deal would be reached in Copenhagen.
David Victor, a political scientist who has written about climate negotiations since 1990, said it is unlikely a comprehensive treaty can be finalized this year.
"The world economic recession has made most governments acutely aware of policies that could affect economic growth," he said. "And the range of issues on the table in Copenhagen is so large and complex and the time available to sort them out is very short."