Just 10 days before the talks in Copenhagen, the body of mostly former British colonies met with UN Secretary-General Ban Ki-moon and two other non-members, French President Nicolas Sarkozy and Danish Prime Minister Lars Rasmussen.

Faced with the "wreckage" of global crises, including the "looming existential catastrophe of climate change," the Commonwealth has to stand ready to prove itself, according to its secretary general, Kamalesh Sharma.

The 53-nation Commonwealth, which includes powers like India and Britain, as well as small island states like Vanuatu and the Maldives, "must set out the responsibilities of countries both rich and poor, and especially of rich countries towards the poor," Sharma said.

Leading the charge, British Prime Minister Gordon Brown proposed setting up a 10-billion-dollar fund to help developing countries tackle global warming.

Britain would contribute 1.3 billion dollars to the fund over three years, he said Friday on his official website, adding he believed the proposal would help break the pre-summit deadlock.

The plan aligns with demands from developing countries that developed nations pay them to slow deforestation and reduce carbon outputs in order to make up for economic disadvantages.

"We have got to provide some money to help that. Britain will do so, the rest of Europe will do so and I believe America will do so as well," Brown said.

Ban, Sarkozy and Rasmussen were invited to address the Commonwealth leaders behind closed doors amid fears the Copenhagen talks would fail to reach a deal on carbon emissions limits to replace the Kyoto Protocol before it expires in 2012.

Climate change and rising sea levels, blamed on global warming caused by greenhouse gases emitted mostly by the world's industrial powerhouses, threaten many developing nations that have struggled to have their voices heard.

Fears the Copenhagen conference would flounder were eased this week with pledges to cut emissions by Beijing and Washington, although questions remain over their effectiveness.

The United States said it was aiming to curb emissions by 17 percent from 2005 levels by 2020, with longer-term pledges of a 30 percent reduction in emissions by 2025, 42 percent by 2030 and 83 percent by 2050.

The cuts are less than calls by the European Union, Japan and UN scientists -- but the first concrete numbers put on the table by the world's largest economy and second-biggest polluter.

China spoke rather of reducing carbon intensity, vowing to cut by 2020 the amount of carbon dioxide emitted per unit of gross domestic product by 40 to 45 percent compared to 2005 levels, which is essentially a pledge of greater energy efficiency.

Britain's Queen Elizabeth II, the titular head of the Commonwealth, said as she opened the summit that the body had an opportunity to shape the global response to emerging challenges.

"The threat to our environment is not a new concern. But it is now a global challenge which will continue to affect the stability and security of millions for years to come," she said.

India, a Commonwealth member home to a billion people, has yet to unveil its own emissions targets ahead of Copenhagen.

Indian Environment Minister Jairam Ramesh said China's announcement had put pressure on India to follow suit.

"China has given a wake-up call to India," the minister told the Hindustan Times daily.

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