It is likely to be released this year after at least two years of preparation and bureaucratic bargaining, he said.

The plan showed that China was joining deepening global alarm that greenhouse gases from factories, power plants and vehicles are lifting average temperatures and will seriously, perhaps calamitously, alter the world's climate, said Zou.

"All this shows that the Chinese government is paying more and more attention to this issue," he said. "When it's approved and issued it will be China's first official, comprehensive document on climate change."

Last week a UN panel of scientists warned that human activity is almost certainly behind global warming.

The expert group gave a "best estimate" that temperatures would rise by between 1.8 and 4.0 Celsius (3.2 and 7.8 Fahrenheit) in the 21st century, bringing more droughts, heatwaves and a rise in sea levels that could continue for over 1,000 years even if greenhouse gas emissions are capped.

China is galloping to become possibly the world's third-biggest economy by 2008, overtaking Germany and lagging only Japan and the United States. And it may become the world's biggest emitter of greenhouse gases by 2009, overtaking the United States, the International Energy Agency has forecast.

Beijing's public reaction to the panel's finding has been muted but behind the scenes it is paying attention to the raft of warnings, said Zou, who has been a member of Chinese delegations to international climate talks since 2000.

Zou said the programme was awaiting approval from China's cabinet, or State Council, after being vetted by over a dozen ministries and agencies, but preparations for a major Communist Party congress later this year may slow its release.

The dilemma facing President Hu Jintao is how to translate concern into policies that deliver growth and jobs while cutting fossil fuel use and greenhouse gases, said Alan Dupont, an expert on climate change and security at the University of Sydney.

"The whole stability of the regime and, as Hu would see it, the future of his country, depends on the continuation of economic growth of 8 and 9 percent," Dupont said.

"But the realisation is dawning on them that China will not get to where it wants to go unless it deals with climate change."

DYING RIVERS, RISING SEAS

In China's secretive, top-down government, few major policy shifts are advertised beforehand. But there have been growing signs that Beijing is worried about how global warming could frustrate ambitions for prosperity, stability and influence.

Climate experts have been preparing a presentation on global warming for China's top leaders, the first time one of their regular study sessions will be devoted to climate change and a sure sign the issue is climbing the political ladder, said Zou.

In late January, the former chief of energy research in China's powerful National Development and Reform Commission, Zhou Dadi, warned in a speech that pollution and climate change have become a "major constraint" on national economic development.

The country's plans to develop its impoverished west could be imperiled, Zhou said, adding that if the glaciers melt away and precipitation is extremely uneven, the whole ecology of China's northwest will be unsupportable. "Don't mention development, it won't even allow people to live," he said.

Zou and other experts have spelled out other worries in a series of recent assessments, warning that global warming may trip up China's sprint for middle-class prosperity.