Fresh studies are published almost every week that add to evidence of man-made climate change, but the problem merited only an oblique mention in the meeting's final communique on Sunday: an unspecified commitment to "reduce greenhouse gas emissions."

And the only global weapon for tackling the threat -- the Kyoto Protocol -- did not rate even a single reference, in deference no doubt to US objections to it and to the troubled state of international relations today.

It was the first time that the "K" word had been bleached out of the G8 environmental parlay since President George W. Bush, an unashamed opponent of the climate change pact, took office in January 2001.

The previous ministerial get-togethers, in Trieste, Italy in 2001 and in Banff, Canada, in 2002 each had a reference to Kyoto that accommodated US objections to it.

Kyoto requires industrialised signatories to cut emissions of carbon pollution, released by burning oil, gas and coal, by a target date of 2008-12 compared with their 1991 levels.

These "greenhouse gases" linger invisibly in the atmosphere, trapping heat from the Sun and causing the temperature of the seas to rise, with what could be catastrophic changes on the Earth's climate system a few decades from now.

Abandonment by the United States, the world's biggest fossil-fuel polluter, almost destroyed efforts to complete Kyoto and ignited a huge row with the European Union.

Eventually the pact was saved thanks to EU concessions to other countries, but under the mathematics of its rulebook, ratification by Russia is vital for it to take effect.

Sources said Kyoto's quasi-invisibility here was in deference to the international political mood, where the emphasis is on restoring calm and dialogue after the storms of the Iraqi war.

"We know where we stand, so there is little use in discussing it," European Environment Commissioner Margot Wallstrom told AFP, when asked whether she had discussed Kyoto with US Environmental Protection Agency (EPA) Administrator Christie Whitman.

Russia's junior minister for natural resources, Irina Ossokina, admitted that there was a split within her government about Kyoto, but insisted the treaty would be ratified as promised.

"I would like to underline that we at the ministry of natural resources are wholly and truly for the ratification of the kyoto protocol... but unfortunately we have a difference of opinion within the country," she said.

"We were hoping to ratify this summer but we were having differences with our economic advisors," she said.

"But we are trying to (resolve) this as soon as possible to have the opportunity for our president to see you straight in the eye at Evian to just tell you the exact date," she said, referring to the G8 summit at a French resort in early June.

The problem lay in calculating Russia's expectations of revenue from a trading system that will be set up under Kyoto, Ossokina said.

Under it, countries that are below their pollution quota that sell that margin to countries that are above their quota, thus applying a powerful financial incentive to polluters to clean up their act.

Russia had initially expected a windfall, because its pollution output has fallen dramatically because of the collapse of the energy-inefficient Soviet economic system. It thus hoped to be able to sell huge "surpluses" to the United States, the biggest polluter.

But the pullout by the United States has meant that the future carbon market has lost its biggest buyer and prices are likely to plummet in consequence.

The G8's communique on Sunday pledged to achieve "the ultimate objective" of Kyoto's parent treaty, the United Nations Framework Convention on Climate Change (UNFCCC), which the United States has signed and ratified.

The group comprises Britain, Canada, France, Germany, Italy, Japan, Russia and the United States, as well as the European Commission.

SPACE.WIRE