As the world's biggest emitter per capita of greenhouse gases, Qatar faces a test of credibility but also an opportunity when it hosts the UN forum on climate change in December, say veteran watchers of the process.

Qatar's population of less than two million pumps out some 53.5 tonnes per person of heat-trapping carbon dioxide into the atmosphere per year, according to United Nations statistics.

This is 20 tonnes more than the closest runner-up (the United Arab Emirates), three times more than the United States, 10 times more than China -- and a massive 36 times more than the average Indian.

So eyebrows were raised five months ago when the CO2-spewing emirate was chosen to host the next meeting of ministers under the UN Framework Convention on Climate Change (UNFCCC).

Qatar faces numerous political and logistical hurdles in this latest bid to boost its profile, said delegates attending intermediate climate talks this week in Bonn.

But they also saw a chance for Qatar to hammer home the problems of climate change in a region where the issue is dormant or dismissed.

"We see it as an opportunity, because now Qatar and the whole region need to show leadership, to give a signal to the international community that they are serious about climate change," Wael Hmaidan, director of activist group Climate Action Network, told AFP.

UN climate chief Christiana Figueres said the December meet "is an open invitation to all of the Gulf states to use the COP in Qatar to showcase what they also are doing to contribute to adapting climate change."

The COP is an annual UN climate meeting or Conference of Parties.

"Most if not all of the Gulf states are very vulnerable to climate change. They all suffer from decreasing water availability. And they understand it is also in their interest to contribute to the solution," Figueres said.

Qatar is a low-lying peninsula with all its cities on the coast, and would be devastated by rising sea levels caused by global warming.

The emirate set out a stall in Bonn, busily handing out flyers and making hotel bookings.

But some observers said they were worried it had not been as busy on the political front as in tourism.

"We have seen Qatar attend a lot of meetings but more on the absorbing side still rather than leading," said Hmaidan.

COPs are usually hosted by larger or richer economies. In previous years, they have been staged in South Africa, Mexico, Copenhagen and Poland.

The test for smaller countries is to show the diplomatic muscle or will to push 194 nations into a deal; lodging thousands of delegates, many of them on tight budgets; and dealing with sometimes rowdy protests by green activists and campaigners for the poor.

On the logistics side, Qatar successfully staged a major conference of the Convention on the International Trade in Endangered Species (CITES) in March 2010 and is hosting football's World Cup in 2022.

Meena Raman from an NGO called Third World Network said Qatar could be trusted to play a neutral role as conference chairman.

The role of a COP president "is not to intervene and direct parties to do what they want," she said. "The role of a host is supposed to help the parties do the negotiations in a transparent, inclusive process."

No Qatari official was willing to speak to AFP in Bonn, but a spokesman sought to give an assurance that the country was "engaged at the highest level in its hosting obligations".

Hmaidan said Qatar needed a stronger presence, rallying the Arab world to stand tough on global warming.

"We have seen Qatar playing a very progressive political role in the Arab Spring. They are very well situated in terms of political ambition, (the need to) avert climate change impact and economic interests to be leaders in the climate change debate.

"Qatar can change the way the Arab region has so far engaged with climate change issue."

Algerian diplomat Rafik Hiahemzizou said climate change threatened the Arab world with spreading deserts, rising sea levels and water shortages.

"What is important in climate negotiations is to take into account the interests of all, regardless of whether they are a culprit or a victim," he said. "Oil producers are also faced by the effects of climate change."