* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.Debate on differentiation has held back progress in Paris on a range of issues, experts say
(Updates with latest version of draft agreement)
U.N. talks on a new global climate change deal expected in Paris this week were hamstrung on Wednesday over how to distinguish between action by rich and poor nations - an issue that affects many aspects of the agreement, from aid to emissions reductions.
French Foreign Minister Laurent Fabius, releasing the latest version of a draft agreement mid-afternoon, said the question of "differentiation" was one of three cross-cutting issues that still needed "deep, in-depth discussion".
Late on Tuesday, ministers leading negotiations to iron out the problem said fault lines remained, and countries were not yet ready to put their final positions on the table.
Developed countries want lower-income nations to take on more responsibility for tackling climate change, and to eliminate a long-standing rule that rich states should assume more of the burden.
But developing countries, led by India, are kicking back against this because they are unhappy with the levels of funding and technological support on offer to help them curb their emissions and deal with the growing impacts of extreme weather and rising seas.
They also argue they have done their bit, as the vast majority have submitted national climate change action plans to the United Nations - as have rich nations - laying out what they will do to curb their planet-warming emissions.
India's environment minister, Prakash Javadekar, told journalists on Tuesday there was "no question" of diluting the concept of "common but differentiated responsibilities" (CBDR) to lessen the difference between industrialised countries and the rest of the world.
"Developed countries are hell-bent on changing this principle - so we can expect a big fight," said Meena Raman, a negotiations expert with the Third World Network.
Wealthy governments have argued in recent months that CBDR was drawn up in the 1990s, and the world has since changed, with emissions from emerging countries like China and India rocketing as their economies develop.
"But the world has not really changed, because in terms of poverty eradication challenges, and the number of people who have been suffering, and emissions that have largely been historical - these cannot be written away," Raman said.
TAINTING THE TALKS
Sam Smith, head of green group WWF's climate and energy initiative, said the debate on differentiation was holding back progress in Paris on a range of issues, as the talks due to end on Friday entered their final stretch.
For example, when it comes to finance for poor countries to boost their climate action, the United States, the European Union and others have been pushing for the Paris agreement to expand the pool of donors to include countries that are also "in a position" to contribute.
That would bring in countries like China, Mexico or South Korea, which are already providing substantial amounts of money for other developing nations.
The Group of 77 and China, a negotiating bloc of some 134 nations, has campaigned against widening the group of countries that have a responsibility for giving money, though some in the group have indicated they could accept it providing their contributions would be voluntary.
Brandon Wu, a climate finance expert with ActionAid USA, said finance had been "one of the most disappointing issues" so far at the Paris talks.
"All (developed countries) want to do is talk about expanding the pool of contributors," he said.
Last week, many donors recognised that a $100 billion annual goal by 2020, fixed in 2009, could be specified as a floor for finance after 2020, when the new agreement kicks in.
But the EU, the United States and Japan said they would only consider a collective contribution target for after 2020 if the donor pool expanded.
Wednesday's text includes language that makes a clear distinction between traditional donors and new contributors, proposing they "may on a voluntary, complementary basis, provide resources to developing countries, including through South-South cooperation initiatives".
Another major sticking point at the talks is the future of a mechanism for dealing with the unavoidable "loss and damage" from global warming, such as rising seas and creeping deserts.
The United States is insisting on including language that rules out "liability and compensation" related to loss and damage, as it fears it could end up with a soaring bill.
But Julie-Anne Richards, an expert with the Climate Justice Programme, said this amounted to "creating a bogeyman that doesn't exist", as the G77 had already agreed to avoid any reference to compensation earlier in the year.
Developing countries and climate change campaigners have expressed pleasant surprise that some key industrialised nations have sided in Paris with their call for limiting global warming to 1.5 degrees Celsius, rather than an internationally agreed limit of 2 degrees.
But the world has already heated by around 1 degree over pre-industrial times - and some doubt whether the tougher target is actually achievable, and are suspicious of developed countries' motives in aligning themselves with it.
"With what’s currently on the table, rich nations are still holding the purse strings, unwilling to commit to their fair share of acting to save the people and their planet," Adriano Campolina, chief executive of ActionAid International, said after the new draft text was published.
Our Standards: The Thomson Reuters Trust Principles.