Rich countries must commit to deeper cuts in greenhouse gas emissions if they want China and India to sign onto an accord to curb global warming, the top U.N. climate official said on Friday.
"We need to see that leadership from rich countries," said Yvo de Boer, executive secretary of the U.N. Climate Change Secretariat, at the World Economic Forum. "Without rich country leadership, we will not get developing country engagement."
Global leaders hope to reach agreement at a U.N. climate summit in Copenhagen in December, but de Boer said negotiations are moving so slowly that it will be impossible to reach a comprehensive deal by then. He said the Copenhagen meeting should aim instead to agree on "key cornerstones" of emissions cuts and how to finance them.
Key sticking points are how much the United States and other industrialized countries can cut emissions and how much developing economies can be expected to reduce the rapid growth of their own. Washington has said it is committed to reaching a deal as long as other major polluters such as China and India do their part as well.
"We need to get clarity in Copenhagen on what developing countries, especially major developing countries like China and India, will do to limit the growth of their emissions," de Boer said at a news conference. "Without developing country engagement, it is impossible for countries like the United States to ratify a Copenhagen agreement."
On Thursday, Chinese Premier Wen Jiabao indicated Beijing might take a tough line in Copenhagen. In a speech at the World Economic Forum, Wen told foreign business leaders that rich economies have a "historical responsibility" to cut emissions and that any deal should take into account countries' levels of development.
Government leaders are expected to discuss the pact at a special U.N. meeting in New York next month, followed by a gathering of the Group of 20 major economies hosted by President Barack Obama in Pittsburgh.
Scientists say carbon dioxide and other industrial gases are trapping the sun's heat in the atmosphere, causing changes in weather that could lead to crop damage, the spread of deserts and flooding in low-lying countries.
The Copenhagen meeting is meant to create a successor to the Kyoto Protocol, which bound 37 industrial countries to reduce greenhouse gas emissions by 5.2 percent from 1990 levels by 2012.
Kyoto placed no obligations on developing countries. In this round, wealthier nations want developing countries, especially China and India, to share the burden and agree to slow their explosive emissions growth.
Offers of emissions cuts from wealthy countries so far total 15 percent to 21 percent below 1990 levels, according to de Boer's agency. The United States has yet to make a formal offer.
De Boer said bigger cuts of 25 percent to 40 percent are required, and below that, "I think the public of the world will not feel that governments have stood up to the challenge."
The world's poorest, most vulnerable countries banded together at a meeting last month in Bonn, Germany, to press industrialized economies for bigger cuts.
The poor states said climate change is outpacing the best estimates of a few years ago, when scientists warned that the maximum safe increase in the planet's average temperature was 2 degrees Celsius (3.6 degrees Fahrenheit) from pre-industrial levels.
The U.S. House of Representatives has passed a climate bill that would impose trade penalties on countries that do not accept emissions limits. President Barack Obama has opposed attaching trade issues to climate and energy legislation.
India has criticized the U.S. lawmakers' approach and proposed a clause that would forbid any government from erecting trade barriers to punish a nation that refused to accept limits on its carbon emissions.