European and UN leaders are urging Vladimir Putin to take the opportunity to confirm Russia?s ratification of the Kyoto agreement on curbing greenhouse gas emissions.

The venue and timing of the World Climate Change Conference are particularly relevant, since it is Russia which is currently holding up implementation of the agreement signed seven years ago in Japan.

The formal agenda is restricted to around 500 scientific papers on the latest research into global warming, but the fate of the troubled Kyoto Protocol on reducing greenhouse gas emissions will loom large in the background.

The signs do not look good. With the United States refusing to take part, the rules of Kyoto require all the other major industrial powers to ratify the agreement before it takes the force of international law.

Only Russia has so far failed to do so, despite an apparent assurance a year ago that it would. This has provoked repeated protests from the European Union, which has already drawn up detailed proposals to limit emissions from its own industry from 2005.

And it is also irksome for countries such as Canada and Japan which have gone ahead with ratification in the teeth of considerable domestic opposition.

Static targets

What puzzles international observers is why Russia has such a problem with Kyoto, since on the face of it the country has secured an extraordinarily good deal from the agreement.

Its target for the period 2008-12 is to keep emissions of carbon dioxide and other gases linked to climate change at the same level as in 1990, compared with an average cut of just over 5% for the industrialised world as a whole.

But since 1990 coincided with the collapse of traditional state-subsidised industry after the demise of the Soviet Union, emissions are already much lower than they were ? not because factories are a lot cleaner ? but simply because there are fewer of them.

Under the Kyoto system, this leaves Russia with ?spare? pollution allowances which it can sell to other countries to help them fulfil their own targets.

This provides Russia with an opportunity to attract considerable foreign investment to renew its ageing energy system.

Puzzled observers

True, the scale of that investment is much smaller than it would have been had, the world?s biggest ?polluter?, the US, still been engaged in Kyoto.

But many other countries will still struggle to achieve the cuts to which they are pledged, so there is likely to be international demand for Russia?s allowances.

Yet in the days leading up to the Moscow conference, several senior Russian officials have played down expectations of an imminent announcement on ratification of Kyoto.

Their message has been that until there are firm commitments of investment from foreign companies, the EU and others will ?wait in vain?.

Even the most seasoned experts in the field of international climate politics have difficulty interpreting exactly what Russia?s motives are.

It could be brinkmanship ? waiting for the best possible financial deal; a response to quiet pressure from the Americans keen to see Kyoto collapse; or the result of in-fighting between various parts of the complex government machine.

It will all make for lively discussion over the next few days in Moscow, and no one seems to know quite what to expect.

Factbox

What is the Kyoto treaty?

Russia?s announcement that it is planning to ratify the Kyoto Protocol makes the international climate change agreement?s implementation increasingly likely in the near future.

The protocol was drawn up in 1997 in Japan and elaborates upon the UN?s Framework Convention on Climate Change which dates back to the 1992 Earth Summit in Brazil. But it needs to be ratified by countries who were responsible for at least 55% of the world?s carbon missions in 1990.

So far, some 178 countries have signed up to the treaty, including all the major industrialised countries except the United States. When it takes effect in 2008, the treaty will require all signatories to achieve emission reduction targets. With that aim, it will provide a complex system which will allow some countries to buy emission credits from others.

For instance, a country in western Europe might decide to buy rights or credits to emit carbon from one in eastern Europe which could not afford the fuel that would emit the carbon in the first place. The US produced 36% of emissions in 1990, making it the world?s biggest polluter. The fact that the Kyoto agreement was finalised without Washington was widely credited to the European Union, in a deal struck at climate talks in Bonn last summer. The EU made considerable compromises allowing countries like Russia to offset their targets with carbon sinks ? areas of forest and farmland which absorb carbon through photosynthesis.

The Bonn agreement also reduced cuts to be made to emissions of six gases believed to be exacerbating global warming ? from the original treaty?s 5.2% to 2%. It was hoped at the time that the compromises were agreed that the slightly watered down provisions would allow the US to take up the Kyoto principles ? but this has not proved to be the case.