Russia's climate politics are something of a mystery to outsiders, but the Russian government has reportedly decided to ratify the Kyoto Protocol on climate change, and approval by the parliament should be a formality. Thus the last obstacle to the protocol's coming into force is set to be removed.

The decision is emerging in a way that lacks conviction from Russia's political and scientific élite (see Nature 431, 12–13; 200410.1038/431012a), and the country's Kyoto sceptics can still delay matters. What is important, however, is that the first multilaterally binding climate-protection regime now seems certain to see the light of day.

Even more important is the need to tackle the treaty's limitations. The legal force behind some of its key rules — including penalties for countries emitting more greenhouse gases than they should — is questionable. And excess emitters have little to fear: compensation for emissions at a later date could be endlessly postponed.

Another penalty is suspension from emissions trading. But whether the creation of an international emissions market — essential to reduce the costs of implementing the protocol — will provide an efficient tool for reducing ‘hot air’ is yet to be seen. It will soon be tested in the European Union (EU), where emissions trading is set to begin in January. The EU's political leaders, who have pressed ahead despite reservations from large European industries, would be delighted if the Kyoto Protocol were to come into effect then.

Many details of the treaty still await clarification. But its true significance is its potential to establish confidence in the practicability of a complex international climate-protection agreement. In particular, Russia's participation will greatly increase the scope for buying and selling emissions rights, and for gaining credits for exporting ‘clean development’ technologies — key issues for European, Canadian and Japanese industries concerned about the fairness and liquidity of the international emissions market. Whether emissions can be checked against permitted levels remains a key technical challenge.

Russia's ratification should provide a push towards future climate negotiations, and may even prompt the next US administration to take a constructive role. And the authority and credibility of the International Panel on Climate Change can only benefit as well.

The problem of global warming is here to stay, however. Fossil fuels still account for some 90% of the world's energy consumption and are still in abundant supply. Hundreds of millions of people in poorer countries have more spending power, and their consumption is surging, pushing up their energy demand. Any emissions control strategy is therefore ultimately doomed to fail without the inclusion of tomorrow's mega-economies, which are exempted from the need to cut emissions from 1990 levels. Russia's wobbly goodwill provides a glimmer of hope, but our planet's future climate will be determined, above all, in China and India.