BONN, Germany Negotiations meant to avert dangerous climate change are stuck over future emissions restrictions in wrangling at meetings below the ministerial level, undermining the U.N.-backed process.
The pace of talks has slowed since a two-year campaign for a binding deal ending at a Copenhagen summit in 2009, when world leaders failed to deliver, and acrimony lingers.
Developed countries have yet to decide whether to fund additional sessions before an annual ministerial conference in Durban in South Africa in November, pinning this on more progress at a June 6-17 meeting in Bonn, Germany.
"This will depend among other things on the extent of progress made here in Bonn, and whether the political will among parties exists for a further session," said the head of the EU delegation, Artur Runge-Metzger.
Less formal talks started this week in Bonn where they left off in Bangkok in April, hung up on the big picture of how to share future emissions cuts. That debate was above negotiators' pay-grade, said a senior official who declined to be named.
Additional disputes over the agenda at both meetings delayed progress on technical decisions too detailed for ministers, such as how to measure and monitor greenhouse gas emissions, share low-carbon technologies and mobilise climate aid.
The United Nations' 1997 Kyoto Protocol only binds the emissions of industrialised countries, from 2008-2012. Endless debate over the big issue of how to widen the pact to include large emerging economies has reinforced deadlock.
"I'm a little sad participating in these negotiations because the atmosphere is so confrontational," said Akira Yamada, head of the Japanese delegation.
The stakes are very high.
Ministers agreed last year to limit a rise in average global temperatures to below 2 degrees Celsius (3.6 F) above pre-industrial times, seen as the threshold for "dangerous" change such as heat waves, droughts, floods and rising seas.
But so far, the United Nations says that promised curbs on emissions are too weak to reach that goal. Temperatures have already risen by about 0.7 degrees C (1.1 F) with effects such as a thaw of glaciers and disruptions to crops.
Countries have run out of time to launch a new binding deal by 2013, the U.N.'s top climate official, Christiana Figueres, said on Monday, implying a messy, legal gap.
Carbon emissions last year rose at their fastest rate in four decades, and at more than twice the average annual average, data from the energy company BP showed on Wednesday.
The talks can only proceed by consensus, and in Bonn were stuck not only on a new round of Kyoto, but also a proposal from the world's biggest oil exporter, Saudi Arabia, for compensation in case increased climate action cuts revenues of oil producers.
Debate over the agenda made some countries doubt the value of extra meetings before Durban. "Without progress in these two weeks there's no point having another session in the fall," the Colombian delegation told the launch of the Bonn session.
On the big picture, the main knot is how far to involve major emerging economies in climate action after 2012.
Most developing countries say that only developed countries should take action binding under international law, as so far under Kyoto, referring back to a 1992 Climate Convention which enshrines a clear difference in responsibility between developed and developing countries.
"Pledges for developing countries are voluntary," said Silvia Merega, on the delegation of Argentina, which chairs the G77 group of more than 130 developing countries at the talks.
The United States, which never ratified Kyoto, and many other industrialised countries say emerging economies including China must stand behind their actions with equal legal force, saying their differences had blurred since 1992.
"We're not prepared to move if the obligations just point only to those in the developed world," said Jonathan Pershing, the U.S. head of delegation in Bonn.
China is a much bigger economy now, and by far the world's biggest carbon emitter, but its per capita income still lags industrialised economies.
The South African hosts of the next ministerial meeting warned of a challenging conference at the end of the year.
"We are well aware of the fact that deliberations in Durban will be difficult," South African delegate Nozipho Diseko told the Bonn conference.
(Editing by Mark Heinrich)