Disputes between richer and poorer nations threaten meaningful progress on climate change at talks next week in Mexico.
The United Nations climate talks in the Mexican resort of Cancun take place this year with all eyes on China.
The world's biggest producer of greenhouse gases saw its emissions rise by about nine per cent last year.
Beijing has said it would aim to cut the amount of carbon dioxide emitted for each dollar of economic growth.
But it refuses to turn its goal into a binding international target because of fears that would hold back development.
But wealthier nations historically branded the worst offenders say their attempts to cut greenhouse gases will be pointless if China's continue to grow.
Talks in Copenhagen last December ended in rows over the transparency of China's emissions and aid from developed nations to help poorer ones to cope with climate change.
The U.S is the world's second biggest emitter of greenhouse gasses.
President Barack Obama's hopes of capping U.S. emissions in line with other industrialised nations have faded after a shift in political control of the House of Representatives.
Professor Zhang Haibin at Peking University's school of international studies says the apparent inability of the U.S. to meet its own targets could damage good will.
SOUNDBITE: Professor Zhang Haibin, Peking University School of International Studies, saying (Mandarin):
"Everyone is looking at America because at the moment it's very unlikely that they will take any substantial action. This will have a negative impact on China and other countries."
Environment ministers meeting in Cancun will try to agree on some of the building blocks of a U.N. deal to combat global warming.
Many of the 194 nations represented at the talks have given up hope of a new agreement any time soon.
They're putting the emphasis on rebuilding trust after last year's acrimony at Copenhagen.
Most agree on the urgency of action on climate change but they have yet to overcome deep divisions between rich and poor on how to control it.