A renowned expert in the field, Mr Chu has increasingly sounded the alarm on the dire need to address climate change before it is too late.

The planet was threatened with sudden, unpredictable and irreversible disaster, the 60-year-old Chinese-American scientist warned in an internet interview last month.

His nomination turns the page on the eight-year administration of President George W.Bush, who has only belatedly acknowledged that human activity may indeed have played a role in heating up the earth.

Mr Chu has warned that cities such as New York, London, Tokyo, Mumbai and Buenos Aires need to think about erecting huge walls to protect their populations from the rising oceans, as ice caps melt.

The world could expect disasters of a magnitude different from anything we had experienced before, Mr Chu said. He is a Copenhagen Climate Council member a collaboration between international business and scientists, working on a new global treaty to replace Kyoto due to be signed in Copenhagen in late 2009.

For Mr Chu, the latest report by the Intergovernmental Panel on Climate Change, which predicted in 2007 that by the end of the century temperatures will have risen 1.8 to 4degrees, underestimates the problem. The current level of greenhouse gases putus on track for temperature increases of more than 6.1 degrees by the end of the century, he said in the interview, published by the Copenhagen Climate Council.

And he scolded governments for failing to address the scale of the problem, saying they were acting like a homeowner who discovers he has faulty wiring and needs to make costly repairs. ''What we are doing is the equivalent of dealing with the problem by ... investing in a set of fire extinguishers that can help us fight the fire, but won't prevent it happening in the first place,'' he said.