But it was Gore, who has become a guru for environmentalists, who stole the show as the United Nations turned its attention to the global ramifications of climate change and the need to curb greenhouse gas emissions.

"We have to overcome the paralysis that has prevented us from acting and focus clearly and unblinkingly on this world crisis, rather than spending time on Anna Nicole Smith and O.J. Simpson and Paris Hilton," Gore said, drawing applause in referring to widely chronicled US scandals.

Schwarzenegger said: "The time has come to stop looking back at the Kyoto Protocol.... The rich nations and the poor nations have different responsibilities, but one responsibility we all have is action."

UN Secretary-General Ban Ki-moon joined that call to action in his remarks to about 80 world leaders who met to focus on the problem of climate change. "Today let the world know that you are ready to shoulder this responsibility and that you will address this challenge head on," he said.

The session is meant to gather momentum for a meeting in Bali, Indonesia, in December where negotiators will start work on a climate treaty to succeed the Kyoto Protocol, which set binding emissions targets for 36 developed countries. The Kyoto plan expires in 2012.

'TECHNOLOGICAL REVOLUTION'

US Secretary of State Condoleezza Rice represented the United States at the climate meeting, urging a technology revolution to combat global warming.

"Put simply, the world needs a technological revolution," Rice said. "Existing energy technologies alone will not meet the global demand for energy while also reducing emissions to necessary levels."

Lo Sze Ping of the environmental group Greenpeace China sounded a similar note but took aim at inertia by some rich countries on setting targets for curbing greenhouse gases.

China's national climate change program commits China -- considered in at least one study to be the world's biggest emitter of climate-warming pollution -- to binding targets for renewable energy and energy efficiency, Lo said.

These targets, Lo said, are "stronger and more ambitious than in certain industrialized countries."

"At the climate negotiations in December, you leaders of the world must therefore agree to nothing short of a ... mandate -- not a roadmap leading to nowhere, not a wish list," Lo said.

President George W. Bush did not attend on Monday but was to dine with Ban, representatives of countries that emit the most greenhouse gases and island nations most at risk from rising seas forecast as a result of global warming.

European Commission President Jose Manuel Barroso, representing countries that emit 15 percent of the world's climate-warming carbon dioxide, told Reuters: "We can succeed only if we have the United States with us."

"We can wait no longer," said French President Nicolas Sarkozy. "It is our duty to make decisions straight away because otherwise it is going to be too late."

Bush has rejected the Kyoto Protocol, an international agreement that requires 36 industrial nations to cut greenhouse emissions by at least 5 percent from 1990 levels by 2012.

He contends the accord unfairly burdens rich countries while exempting developing countries like China and India and that it will cost US jobs.

Developing countries have said it is unfair to ask them to curb their emissions as their economies grow while industrialized nations have been polluting for decades.