Should the Kyoto Protocol, the only international curb on greenhouse gases, be allowed to die?

Even the question smacks of heresy to many nations at UN climate talks, but a few voices in the South African city of Durban are saying that the treaty has become more hindrance than help in the long-haul fight against climate change.

Coming into the 12-day climate talks under the UN Framework Convention on Climate Change (UNFCCC) which end Friday, Kyoto's fate was hanging by a thread.

The Protocol's first round of emissions pledges by rich countries expires next year. By design, developing nations are exempt from its obligations.

So far, however, only the European Union, which accounts for barely 11 percent of global CO2 emissions, has shown any enthusiasm for renewing its vows.

And even then there is a condition: all the world's major emitters -- including the United States and China -- must agree in principle to conclude a binding climate pact by 2015 and implement it by 2020.

So far, there are few signs that they will.

The treaty's defectors such as Japan, Canada and Russia favour shifting pledges to a parallel forum in the 194-nation UNFCCC that focuses on voluntary emissions curbs, as does the United States, which never ratified Kyoto.

"The Protocol has given us a good basis on how we should work on the climate change issues," a senior Japanese negotiator said on condition on anonymity.

"But I also have to be realistic, looking at the emissions numbers, can it give us a result? Unfortunately, the answer is absolutely 'no'."

But the Protocol's defenders -- the entire developing world, led by China and virtually all green groups -- have made its renewal a redline issue.

"Having a second commitment period is the most important issue at Durban," Xie Zhenhua, China's top climate negotiator, told journalists a day before the start of high-level talks among some 130 ministers.

"The most important issue for us in Durban is that a clear and ratifiable decision on KP's (Kyoto Protocol's) second commitment period takes place," Indian Environment Minister Jayanthi Natarajan said Tuesday.

But for Elliot Diringer, vice-president of the Center for Climate and Energy Solutions, Kyoto may have run its course.

"Although the Protocol remains an important emblem of multilateralism, it has become, in reality, more of an impediment than a means to genuine progress," he wrote in a commentary in the science journal Nature.

"More important than ensuring Kyoto's long-term survival is building something better to take its place."

Claire Parker, a senior climate change advisor at the International Union for the Conservation of Nature (IUCN), said the treaty's highly symbolic status could ultimately impede progress in the talks.

"The survival of the Kyoto Protocol has become 'totemic' for many developing countries," she said.

"This may stand in the way of a compromise here in Durban" as long as emerging giants China, India and Brazil, along with the United States, fail to make "reciprocal undertakings."

Even EU negotiators make clear that Kyoto's value is more as a lever in the negotiations than a tool for purging carbon from the atmosphere.

"There is absolutely no point in the EU, for entirely totemic reasons, just signing up to a second commitment period when actually we've already have got commitments to these objectives in European law anyway," said Chris Huhne, British secretary of state for energy and climate.

Other countries, still sitting on the Kyoto fence, suggest that the treaty is probably best seen as a bridge toward a more comprehensive agreement.

"You cannot do a deal that leaves 88 percent of emissions out of the framework of commitments," New Zealand's minister for climate Tim Groser told AFP on Tuesday.

"That just does not pass the laugh test," he said, adding that his country was in the "maybes camp" for new pledges.