Negotiators began their first talks Monday in Bangkok on forging a devilishly complex global warming pact to succeed the Kyoto Protocol — and faced wide divisions between rich and developing countries over how to slash greenhouse gases.

The weeklong gathering of representatives from 163 countries launched a 21-month process aimed at concluding a new climate change agreement by December 2009 to rein in gases such as carbon dioxide blamed for the rise in world temperatures.

Organizers of the UN-led talks — mapped out at a massive conference in Bali in December — urged delegates to work quickly to ensure action before the worst effects of global warming such as extreme weather become unavoidable.

"With the 2009 deadline, we have just 1½ years in which to complete negotiations on what will probably be the most complex international agreement that history has ever seen," said Yvo de Boer, UN climate change executive secretary. "And I'm confident that it can be done."

Many scientists and the United Nations agree that the world needs to stabilize emissions of greenhouse gases in the next 10-15 years and slash them by 50 per cent by 2050 to prevent rising temperatures from triggering devastating changes in the environment.

News of accelerating effects of global warming, such as the recent collapse of a massive chunk of Antarctic ice and worsening cyclones and flooding, has put even more pressure on the UN talks to provide decisive action.

The 1997 Kyoto Protocol requires 37 industrialized nations to reduce greenhouse gas emissions by an average of five per cent below 1990 levels between 2008 and 2012. The next pact is aimed at providing for further cuts starting in 2013.

Developing world points finger

The talks in Bangkok this week are to focus narrowly on setting up an agenda for the next two years of negotiations, but the deep differences among countries over the path forward suggested even those discussions would be complicated.

Developing countries, led by rapidly growing China, demand that the bulk of the considerable costs and actions be assumed by rich nations that expanded their economies in decades past by polluting the environment. They also want aid and technology to increase energy efficiency.

Wealthy nations, meanwhile, such as the United States and Japan, say a global pact will only be fair if it calls for up-and-coming polluters in the developing world to take on emissions reduction commitments as well.

On Monday, many delegates argued the first order of business should be to lay out the steps rich nations should take. John Ashe, delegate for Antigua and Barbados, urged the conference to push forward on setting "required deep and ambitious quantified emissions reduction commitments" for developed nations. "We cannot and should not be distracted," he said.

The European Union also strongly supports having wealthy nations take the lead on reducing emissions, backing the inclusion of a reference in the Bali agreement that industrialized countries slash them by 25 per cent to 40 per cent below 1990 levels by 2020.

'Leakage issue' concerns U.S.

The U.S., one of the world's top polluters, has in the past resisted the mandatory national reduction targets of the kind agreed to in Kyoto. Washington also demands that top emitters like China and India share more in the costs of combating warming.

"The primary concern is the so-called leakage issue," U.S. negotiator Harlan Watson told the Associated Press. "If you take commitments and you have energy-intensive industries, they might want to move to other countries which don't have commitments."

Japan, an energy-efficient country where many feel they have done more than others to reduce emissions, has pushed a so-called sectoral approach, under which industries such as cement or steel makers would face similar efficiency targets across borders.

Many in the U.S. and other countries also support this approach as a way of ensuring reduction targets do not burden home industries facing competitors in developing nations.

The proposal, however, has triggered wide concerns that it could be used to transfer burdens to industries in developing countries while allowing rich nations to avoid setting national, economy-wide targets.