Bush has refused to ratify the Kyoto Protocol, the only legally-binding international commitment to curbing greenhouse gases, saying it is not in the United States' interest.

Ban said the UN scientists' report "highlights the scientific consensus regarding the quickening and threatening pace of human-induced climate change".

"The global response therefore needs to move much more rapidly as well and with more determination," he said.

The Intergovernmental Panel on Climate Change (IPCC) -- the UN's top scientific authority on global warming -- delivered its starkest warning yet on global warming on Friday.

It said fossil fuel pollution would raise temperatures this century, worsen floods, droughts and hurricanes, melt polar ice and damage the climate system for a thousand years to come.

South African Environment Minister Marthinus van Schalkwyk urged Bush to hear the "growing groundswell of opinion" in the US and join the global effort to curb global warming.

"Given this compelling scientific case, the lack of political will to act on the grounds of scientific uncertainty has now become indefensible," he said. Australia, which also refused to ratify the Kyoto Protocol, said the IPCC report was "nothing new".

"The science in this report is important but it is not new," said Australian Environment Minister Malcolm Turnbull. "But this is a global challenge and for the world to cut emissions, we need all the major emitting countries to join in global action."

Both Washington and Canberra say booming economies like China and India must sign up to an international agreement to curb greenhouse gases before they will do likewise.

Turnbull insisted the Australian government's response to climate change had been "fast and decisive".

Yet only last week, eminent Australian scientist Tim Flannery said his country was already experiencing the devastating impact of global warming and must urgently undergo an energy revolution to survive. Flannery said that if ever a textbook example of the impact of global warming was needed, Australia provides it.

And the government's own scientific agency said global warming would leave Sydney in permanent drought by 2070, with huge seas battering its beaches and raging bushfires threatening its outskirts. They said the city should start immediate planning.

China's state-run media played down the IPCC warnings and centrally controlled television news ignoring the climate report altogether.

The English-language China Daily -- for overseas readers -- put the news on its front page and carried an editorial on the need to reduce greenhouse gas emissions.

But AFP saw no Chinese-language newspaper mention China's growing contribution to global warming due to its rampant use of coal and booming car industry.

British Foreign Secretary Margaret Beckett issued a stark warning to those unwilling to act. "Failure to grow our economies will threaten peace and prosperity but if we grow our economies at the expense of the climate the same peace and prosperity will be threatened," she said.

French President Jacques Chirac called for a "revolution" in the way the world views the environment. "Soon will come a day when climate change escapes all control. We are on the verge of the irreversible," he said.

The UN Framework Convention on Climate Change urged Ban to convene a summit on global warming.

European Environment Commissioner Stavros Dimas said it was "now more urgent than ever that the international community gets down to serious negotiations on a comprehensive new worldwide agreement to stop global warming". The Kyoto Protocol expires in 2012.

Environmental groups WWF and Friends of the Earth (FoE) urged the 27-nation European Union to take the lead in efforts to control greenhouse gas emissions.

Jan Kowalzig, climate campaigner for FoE, said EU leaders must order a 30-percent emissions reduction target, "which would be just enough to avert the worst of climate change". Greenpeace warned the "window for action is narrowing fast".

Danish Environment Minister Connie Hedegaard stressed the need for agreement with countries outside Europe.

The EU and Denmark "can do something, but for that to have an effect, we have to sign binding agreements with the big economies of the world -- for example China and above all the United States."

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