The signing of the UN accord by Russia's lower house of parliament clears the way for the long-delayed climate change deal to come into force worldwide after the United States withdrew its support in 2001.

To come into force, the pact needed to be ratified by countries accounting for at least 55% of developed nations' greenhouse gas emissions. Already backed by 126 countries, the protocol needed Russia's support to make it internationally binding.

The Federation Council, the Russian parliament's upper chamber, was scheduled to vote on the ratification of the treaty on Wednesday. The ratification process is expected to be completed within a month leaving the United States the only G-8 member not to have ratified the Kyoto Protocol.

The 1997 Kyoto Protocol committed industrialized nations to specified, legally binding reductions in emissions of six greenhouse gases. It obliges rich nations to cut overall emissions of carbon dioxide by 5.2% below 1990 levels by 2008-12 by curbing use of coal, oil and natural gas and shifting to cleaner energies like solar or wind power.

Among the excluded countries are China and India, which respectively are the second and fifth highest emitters of carbon globally. The US is the biggest emitter while Australia emits between 1% and 2% of total global emissions.

The US has long complained the protocol did not address such critical questions as the role of developing countries and how the Kyoto mechanisms would work in practice.

London’s Financial Times predicted three factors could impact on Kyoto. The first is the possibility that the US position will evolve, given greater global pressure, already signalled by EU Commission President Romano Prodi. Secondly, high oil prices are expected to drive development of renewable energies such as wind power. The third factor is a revival of interest in nuclear power.