BEIJING Chinese Premier Wen Jiabao said rich nations must abandon their `unsustainable lifestyle` to fight global warming and give more help to poor nations bearing the brunt of worsening droughts and rising sea levels.

Wen made the demand on Friday, opening a conference to promote his governments call for developed nations to fund a massive expansion in greenhouse gas-cutting technology to China and other developing countries.

China is now widely believed to be the biggest emitter of the greenhouse gases from industry, power plants and vehicles that are lifting global temperatures. But Wen threw the focus back on the role of rich nations.

`Developed countries shoulder the duty and responsibility to tackle climate change and should alter their unsustainable lifestyle,` Wen told the meeting, according to Xinhua news agency.

He urged wealthy economies to do more to help developing countries, including his own, despite the global economic downturn.

Chinese officials have said wealthy nations should divert as much as 1 per cent of their economic worth to paying for the clean technology drive and helping the Third World overcome damage from rising temperatures bringing more heatwaves and droughts, more powerful storms and rising sea levels.

This would mean a total $284 billion a year if all members of the Organisation for Cooperation and Economic Development (OECD) paid up based on the size of their economies in 2007.

More than 190 nations have agreed to seek a new UN treaty to try to cut greenhouse gases from human activity and slow rising temperatures.

And China wants the technology aid to feature in that treaty, which negotiators hope to seal in Copenhagen late next year.

How to pay for it?

But the top United Nations official for climate change said global financial turmoil will make citizens of rich nations reluctant to divert taxes to fighting global warming.

His remarks cast doubt on the Chinese proposal to tie contributions to rich nations GDPs.

`It is undeniable that the financial crisis will have an impact on the climate change negotiations,` said Yvo de Boer, who heads the UN Climate Change Secretariat.

`If we go to citizens under the current circumstances ... and say Im increasing your tax burden in order to pay for climate policy, that might not go down very well,` he told Reuters.

The solution, he said, was to directly target the polluters as a source of revenue to help developing countries.

Speaking ahead of the Beijing conference, de Boer nonetheless warned the rich world that under a roadmap for a climate deal to replace the current Kyoto Protocol, they must create revenues to help developing nations.

The plan agreed in Bali last year committed poor countries to curbing emissions if rich governments helped with technology so they did not have to sacrifice economic growth.

`I just dont see how you can expect delivery on one part of the deal, namely the measurable action, if you dont deliver on the other part of the deal, the measurable money and technology.`