Activists on Monday hold signs urging a vegetarian diet, to help reduce global methane emissions, in the Mexican resort of Cancun where a two-week UN climate change conference is being held. [Photo: Reuters]?

Concessions are being urged, amid calls to sideline narrow interests for humanity's sake, as negotiators from more than 180 countries gathered at the resort city of Cancun on the Caribbean coast on Monday to discuss ways to combat climate change.

The Cancun conference is the first full UN meeting since the failure of the Copenhagen summit a year ago, which brought 120 world leaders to the Danish capital in an abortive attempt to agree to a binding treaty governing man-made emissions.

The president of Mexico, the host country, called on nations to think beyond their borders and consider all humanity.

"The atmosphere is indifferent to the sovereignty of states," President Felipe Calderon said in his keynote speech opening the conference.

"It would be a tragedy if our inability to see beyond our personal interests, our group or national interests makes us fail," Calderon said in the speech to 15,000 delegates, business leaders, activists and journalists.

Industrial and developing countries are divided about their responsibilities in fighting climate change and accepting legal limits on emissions.

But there are signs of progress, according to the UN's climate chief.

Delegates in Cancun are addressing how to raise and disperse the $30-billion "fast-track fund", (to help less well-off nations fight global warming) agreed in Copenhagen and a growing convergence has emerged to agree on a balanced package of decisions, said Christiana Figueres, executive secretary of the UN Framework Convention on Climate Change.

Developed countries have pledged to put on the table a total of $28 billion to help poor countries adapt to global warming.

Cancun also hopes to agree on measures to protect tropical forests and transfer green technology to developing nations.

While an overarching deal to slash greenhouse gas emissions looks out of reach this year, commitments regarding technology transfer and transparency could help restore confidence and pave the way for a legally binding deal next year, Chao Qingchen, a member of the Chinese delegation, told China Daily.

Political tensions are still high between rich and poor countries on issues such as whether the Kyoto Protocol - the only available mechanism to cut global carbon emissions - should continue after it expires in 2012, said Figueres.

Formalizing proposals countries made in Copenhagen is another thorny issue.

"Compromise is an act of wisdom that can unite different positions in creative ways," Figueres told negotiators at the opening ceremony.

The media have highlighted the importance of transparency and accountability in the negotiations.

But for China, transparency won't be a big problem, Su Wei, China's top climate change negotiator, said on the sidelines of the opening ceremony.

China has been active in introducing measures and drafting laws and is committed to concrete action on emissions, Su said. He also said China "did a lot but said little" in energy saving and the country would like to increase the transparency of its policies, actions and achievements.

China will continue its positive and constructive role in negotiations to secure a balanced and comprehensive outcome, he added.

The US hopes that Cancun will achieve "a meaningful outcome", Jonathan Pershing, head of the US delegation, said at a media conference.

He said it is important for the US to work with China during the conference, as both are global economic leaders, the largest greenhouse gas emitters and the two countries have been instrumental in developing clean energy. "We have a lot of areas of agreement," he said, without specifying.

Despite the positive ambience, countries clashed soon after the opening ceremony over the principle of consensus.

Representatives from Papua New Guinea said the consensus-based process has resulted in climate negotiation stalemate.

Others hold that the consensus principle should be the basis for any environment-related negotiation, because "every country has to participate and take action", said a representative of the Indian delegation.