Abdullah Al Attiyah, named by Qatar to the presidency of the United Nations climate-change talks that the country is to host this year, began his term quietly this week.

In many ways he is the obvious choice, having represented Qatar at previous negotiating rounds as a trusted envoy of Doha.

Yet as chairman of Qatar Petroleum and a former oil minister, Mr Al Attiyah also represents the very industry that is the focus of the climate-change talks.

His role represents the difficult balancing act for Gulf states in negotiations on climate change as they seek green credentials while safeguarding their economic backbone of fossil fuels.

"You have a whole lot of vested interests who have a lot of difficulty understanding a world without fossil fuels," said Ian Dunlop,a former chairman of the Australian Coal Association and member of the Club of Rome, a think tank. "A lot of that's conditioned on the fact that a lot of their wealth, whether nationally or personally, comes from fossil fuels."

It is a critical moment for the fight against climate change.

Next month nations' representatives meet in Brazil for a sustainability summit called Rio+20, the two-decade follow-up to the 1992 Rio summit that sparked the international climate-change negotiations that continue today.

The Kyoto Protocol, the only binding agreement aimed at cutting greenhouse-gas emissions, expires at the end of this year, and nations meet in Doha in December to create a system to take its place by 2020.

Although Gulf nations account for a tiny fraction of the world's total pollution, they are among its highest per capita polluters.

In a report released this week by the World Wide Fund for Nature, Qatar, Kuwait and the UAE held the top three spots in a ranking of per capita ecological footprints.

The stances of Gulf nations in climate negotiations span the spectrum, from Saudi Arabia, which has a reputation of being obstructionist, to the UAE, which has gone so far as to host the UN's renewables agency and to build Masdar City, a "carbon-friendly" metropolis.

But even the stances of the hardliners appear to be softening.

This year, Saudi Arabia replaced its representative, Mohammad Al Sabban, a long-time climate negotiator renowned for demanding compensation for oil producers for lost revenue.

"In climate talks, GCC countries moved away from [the Saudi] position," said Mohamed Abdel Raouf, a fellow at the Gulf Research Center who is representing the region at Rio+20. "They feel it is better for them."

A factor in that has been the classification of Gulf nations as "developing countries" by the UN - thus allowing them to take advantage of opportunities to earn credits for projects that reduce carbon emissions such as building solar plants or burying carbon underground.

Saudi Arabia recently announced a plan to provide 41 gigawatts of solar power by 2032, starting with a US$ 109 billion (Dh400bn) investment. The kingdom is also nursing a domestic manufacturing industry for solar wafers and panels.

"The national interest of Saudi Arabia vis-à-vis the opportunities of the green economy is increasingly at odds with its international-level climate-change policy," said Mari Luomi, a climate policy researcher at Georgetown University in Qatar.

"That's why I think personally Saudi has nothing to lose from taking a more neutral role and looking at the opportunity side of the climate regime."

But even as Gulf states study their role in the climate-change negotiations, the most progressive nations could be losing steam.

At negotiations this week in Bonn, Germany, a rift emerged between the European Union and small island states, which had traditionally been aligned in pressing for aggressive climate-change measures.

The EU wants nations to sign up for an extra eight years under the Kyoto Protocol that expires this year, long enough to last through the EU's 2020 deadline for its ambitious climate-change targets. The island states say the period should last only five years to ensure as many nations as possible sign on.

Nations need to push for even higher targets, said Mr Dunlop.

"Even today, what we're doing is we're locking in temperature changes that will happen over the next 20, 30, 40 years," he said. "It's not like we have time. What we're doing is going to effectively guarantee the temperature increase."