UN Secretary General Ban Ki-moon says a one-day climate change summit in New York has given fresh impetus¹ to efforts to tackle global warming.

联合国秘书长潘基文称，纽约一日气候变化峰会对解决全球变暖起到了新的推动作用。

Ban Ki-moon, right, praised world leaders at the summit

He says the momentum² has shifted in favour of reaching a deal at December's crucial climate meeting in Copenhagen.

Earlier, the summit heard that China will increase efforts to improve energy efficiency and cut its CO2 emissions³.

The pledge prompted former-US vice-president and environmental activist⁴ Al Gore⁵ to praise China's leadership.

Chinese President Hu Jintao gave no details about the measures, which should mean emissions grow less quickly than the economy.

China is the world biggest polluter, according to some measurements.

The US, the world's other major emitter, said China's proposals were helpful but figures were needed.

About 100 leaders attended the talks, ahead of the Copenhagen summit which is due to approve a new treaty.

At the close of the meeting, Mr Ban said: "While the summit is not the guarantee that we will get the global agreement, we are certainly one step closer to that global goal today."

He praised world leaders for their desire to tackle climate change.

"Climate change is a defining challenge of our time, he said.

"Today's summit signals a determination of world leaders to address this challenge and reach a substantive⁶（本质的，实在的） deal in Copenhagen."