China pledged yesterday to slow the growth of its emissions despite the rapid expansion of its economy.

President Hu Jintao told nearly 100 leaders at a UN summit on climate change that China would cut carbon dioxide emissions by a notable margin by 2020. “We have taken and will continue to take determined and practical steps to tackle this challenge,” he said.

China, the world’s largest emitter of greenhouse gases, is overwhelmingly dependent on coal. Mr Hu said that it would “vigorously develop” renewable and nuclear energy, try to increase the share of non-fossil fuels to 15 per cent by 2020 and plant 40 million hectares of forest to absorb carbon emissions.

The speech is the clearest indication yet that Mr Hu would be prepared to sign a binding international agreement on emissions. China previously rejected carbon emissions caps or cuts.

Expert View, Jane Macartney "No Communist Party official can hope to win promotion unless he shows his contribution to tackling climate change"
  
Activists were disappointed that he did not set specific targets. Al Gore, the former US Vice-President and Nobel Peace Prize winner, said that he believed that China would offer more if the US responded to its initiative.

Yvo de Boer, the UN climate chief, praised Mr Hu’s speech. “I think this was a significant offer, especially at a time we are still waiting to see what the US is going to do about this.”

President Obama, who faces difficulty in passing climate change legislation in the Senate, offered no fresh commitments. He played down the UN deadline to “seal the deal” at Copenhagen in December, saying only that it should be a significant step forward. He said that the developed world had a responsibility to lead but that emerging economies would account for nearly all the growth in emissions in the decades ahead and therefore had to do their part.

Jennifer Haverkamp, of the lobby group Environmental Defence Fund, said: “It’s striking that China has come to New York with some real proposals while President Obama’s speech was largely rhetorical. The key question is whether these steps will undermine the position of those in Congress who are using concern about China’s lack of action as a reason not to move forward.”

Gordon Brown called on the UN to make $30 billion (£18 billion) available to help poor nations to adapt to the effects of climate change. He said that it was a terrible injustice that the most vulnerable nations were worst affected.