The United Nations secretary general has rebuked the Group of Eight leaders for failing to make more commitments to reducing climate change in the near future.

Secretary General Ban Ki-Moon also says the G8 must come forward with financing for poorer nations to change their polluting growth pattern and adapt to the effects of global warming.

He said Thursday the G8 must do both if developing countries are to cut their own emissions.

The G8 on Wednesday recognised for the first time that average global temperatures should not increase by more than 2.0 degrees Celsius (3.6 degrees Farenheit) from pre-industrial times.

Financial commitments

But the leaders made no commitments to do anything soon to reach that goal and made no firm financial commitments for poor countries.

The White House declined to comment on whether it would sign off on a statement referring to the temperature threshold.

If the deal went through, it would mark a significant step forward since the G8 has previously refused to adopt that temperature limit as a political goal.

Climate change experts say the new threshold, which has been embraced by the European Union and some developing countries, would not eliminate the risk of runaway climate change but would minimise it.

Even a slight increase in average temperatures will wreak havoc on farmers around the globe, as seasons shift, crops fail and storms and droughts ravage fields.

Deeper discussions on climate change were scheduled for Thursday with the 17-member Major Economies Forum that includes China, which has overtaken the US as the world's biggest polluter, and India, which is close behind.

Mexico, Brazil, South Africa, Indonesia, Australia, South Korea and the European Union also are in that club of the world's major polluters.

The climate discussions at L'Aquila come ahead of a crucial December summit in Copenhagen, Denmark, where the United Nations aims to conclude a new, worldwide climate pact.

- AP