Clinton, speaking to the graduating class at University of Texas' Lyndon B Johnson School of Public Affairs, said the United States must pursue policies that make "more partners and fewer enemies" and use "institutionalized cooperation" before there is catastrophic damage from global warming.

"Climate change is more remote than terror but a more profound threat to the future of the children and the grandchildren and the great-grandchildren I hope all of you have," Clinton said.

"It's the only thing we face today that has the power to remove the preconditions of civilized society," he said. "I am not one of those who is pessimistic about the future of the world, assuming we get off our butts and do something about climate change in a timely fashion."

During Clinton's administration, the global Kyoto Protocol to curb the release of greenhouse gases was created but the Bush administration has rejected it on grounds it will hurt the US economy. "I think we should be in the Kyoto climate change system," Clinton said.

"We can't solve global warming or any other problem in the world you can mention that amounts to a hill of beans by ourselves. The United States is considered the largest emitter of the "greenhouse gases" blamed for global warming.

President George W Bush has said that global warming may be occurring but its cause is not clear.

United Nations secretary general Kofi Annan had already stressed that developed countries, particularly the United States the world's leading emitter of greenhouses gases must take the helm in stemming global climate change.