US President Barack Obama has challenged the world to act swiftly to fight global warming. Speaking at a special UN meeting, Mr Obama said time was running out to reverse climate change.
He said: "Our generation's response to this challenge will be judged by history, for if we fail to meet it - boldly, swiftly, and together - we risk consigning future generations to an irreversible catastrophe. The security and stability of each nation and all peoples - our prosperity, our health, our safety - are in jeopardy. And the time we have to reverse this tide is running out."
China's President Hu Jintao said China would reduce the amount of greenhouse gasses produced for each dollar of national economic output by a "notable margin" by 2020 from 2005 levels. But neither head of state outlined specific new targets.
Green activists hope action by the US and China will inject momentum into the fight against climate change ahead of the Copenhagen summit in December. But UN Secretary-General Ban Ki Moon, who called the meeting, said talks were moving too slowly. He said: "Failure to reach broad agreement in Copenhagen would be morally inexcusable, economically short-sighted and politically unwise."
"We cannot go down this road. If we have learned anything from the crises of the past year, it is that our fates are intertwined," he said.
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