March 23 (Bloomberg) -- China, the world’s largest producer of greenhouse gases, and dozens of developing nations will be asked to consider accepting their first binding targets for reducing global-warming pollution.

The cuts, to be made by 2050, are highlighted by the United Nations in a document guiding negotiations that start in six days in Bonn. The UN will supervise talks among 192 countries through December and is leading efforts to find common ground to stem climate change.

The UN whittled down hundreds of proposals circulating to get poor and rich countries to focus on closing a gap that threatens to derail a deal. Nations are closer to agreeing on a year for a long-term emissions target, 2050, and on how to fund greenhouse-gas reductions in poor countries, the UN said today.

“In a number of areas there is a very clear convergence and countries are quite close to each other,” Yvo de Boer, the UN’s top climate official, said in a telephone interview from Germany. Still, “there are a number of areas where a lot of blanks need to be filled in.”

China and India are among developing countries that have rejected adopting any targets until industrialized nations first make reductions. They argue that countries in North America and Europe were responsible for most of the buildup of heat-trapping emissions in the atmosphere blamed for warming the planet, dating to the beginning of the industrial age.

Developed nations need to make “strong commitments” on emissions cuts they’re prepared to make by 2020 in order for talks to move forward, Su Wei, China’s lead negotiator, said today in an interview.

Quadruple 1980 Levels

The world’s most populous nation surpassed the U.S. in carbon-dioxide emissions in 2006 when it released 6.02 billion tons into the skies, more than quadruple 1980’s levels, U.S. government data on Bloomberg show. Neither country is subject to targets under the existing treaty, the Kyoto Protocol, whose binding limits expire in 2012.

Jim Watson, director of the Sussex Energy Group at University of Sussex in Brighton, England, said developing nations may not this year accept limits even as far off as 2050.

“If I was in the government of the developing country, I would ask ‘why should we?’” he said.

The target proposed by Madagascar for less-developed nations -- to reduce emissions 25 percent by 2050 from 2000 levels -- is new in that it wasn’t part of a similar UN summary prepared before the climate-change talks in Poznan, Poland, in December. The current document will be refined throughout the year, and a treaty negotiating text must be on the table by June in preparation for agreement in December at a meeting in Copenhagen.

Concessions May Loom

Developed countries will have to make more concessions if they want to persuade developing nations to accept targets, said Miles Austin, a spokesman for Dublin-based EcoSecurities Plc, which develops projects that reduce carbon emissions.

“Rich nations will struggle, in the absence of per capita emissions targets, to achieve agreement on hard targets from developing nations in Copenhagen,” Austin said in an interview.

Global emissions need to be brought to virtually zero by 2050 to avert the worst effects of climate change, including rising sea levels and melting glaciers, said Stephanie Tunmore, climate campaigner for the environmental group Greenpeace.

“It’s hard to see a 25 percent reduction from 2000 levels by developing countries would be enough,” Tunmore said today. “The main historical responsibility does fall on the developed world and in order to persuade developing countries to act, they’ll have to show they’re completely serious about deep and rapid cuts in their own emissions.”

‘Clean Development’ Concerns

China’s Wei said there will be concern about the viability of the Clean Development Mechanism, the UN market in carbon credits that allows rich nations to make their required emissions cuts by investing in clean-energy projects in developing nations.

“The future of the CDM is very much dependent on whether we are going to have deeper cuts by developed countries for the period after 2012,” Su said today in a telephone interview from Beijing. “We don’t have much time.”

The 23-page document, posted on the Web site of the UN Framework Convention on Climate Change and dated March 17, says there is “convergence” among countries over the need for a long-term goal for emissions cuts to be set for 2050 and that emissions need to peak within the next 20 years. At the same time, there’s a lack of agreement on what different countries should contribute to the goal, it said.

First of Four Sessions

The paper was drafted by Michael Zammit Cutajar, who leads one of two sets of talks under the UN, and will be discussed in Bonn, the first of at least four negotiating sessions this year.

Proposals include requirements for industrialized nations to cut emissions by as much as 40 percent from 1990 levels by 2020 and by 95 percent by 2050 and for developing countries to depart from “business-as-usual” emissions growth.

There is also a “growing consensus” that actions taken by developing nations to reduce emissions should be included in a registry that matches funding from rich countries with projects in poorer ones, the UN’s de Boer said. That would give a more binding nature to developing country commitments, he said.

“If there’s international financial support involved, things then become more formal, certainly in terms of measurement,” de Boer said. “The finance is contingent on a solid plan and implementation of that plan.”

To contact the reporters on this story: Alex Morales in London at amorales2@bloomberg.netMathew Carr in London at m.carr@bloomberg.net

Last Updated: March 23, 2009 14:34 EDT