Climate fears 'being realised''

In a statement in Copenhagen on their six key messages to political leaders, they say there is a increasing risk of abrupt or irreversible climate shifts.

Even modest temperature rises will affect millions of people, particularly in the developing world, they warn.

But, they say, most tools needed to cut carbon dioxide emissions already exist.

More than 2,500 researchers and economists attended this meeting designed to update the world on the state of climate research ahead of key political negotiations set for December this year.

New data was presented in Copenhagen on sea level rise, which indicated that the best estimates of the Intergovernmental Panel on Climate Change (IPCC) made two years ago were woefully out of date.