Barack Obama failed to impress his political contemporaries or ecological campaigners with his eagerly-anticipated speech on climate change.

The US has been the subject of almost constant criticism from ecological campaigners in recent times, due to its high level of carbon emissions and failure to ratify the Kyoto Protocol.

It had been hoped that President Obama's arrival in the White House would signal a dramatic change in policy, but his speech to the United Nations was a disappointment.

He acknowledged that the US has been too slow to act on climate change and claimed that it was now taking more steps than ever before to combat the threat of global warming.

However, the rhetoric was not backed up by the kind of detail ecological campaigners wanted and worryingly, the president also made a point of saying that the recession would make it much more difficult to take effective action on climate change.

It was not what EU politicians wanted to hear and it was certainly not what Friends of the Earth wanted to hear.

Asad Rehman, Friends of the Earth's senior international climate change campaigner, described President Obama's speech as "a missed opportunity" and called on him to make a firm commitment to cut emissions by 40 per cent.

"It's time for the President to say 'yes we can' to the growing calls for US leadership on this crucial issue," Mr Rehman added.