President Vladimir Putin (search) has signed a bill confirming Russia's ratification of the Kyoto Protocol, the Kremlin said Friday, clearing the way for the global climate pact to come into force early next year.

Both houses of parliament last month ratified the protocol, which aims to stem global warming by reducing greenhouse-gas emissions. Putin signed the bill on Thursday, the Kremlin said.

Without Russia's support, the pact — which has been rejected by the United States and Australia — could not have come into effect. It needed endorsement by 55 industrialized nations accounting for at least 55 percent of global greenhouse gas emissions in 1990.

The United States alone accounted for 36 percent of carbon dioxide emissions in 1990, while Russia accounted for 17 percent.

After years of hesitation, Putin pledged in May to speed up approval in return for the European Union's support of Russia's bid to join the World Trade Organization (search). The 1997 pact would take effect 90 days after Russia notified the United Nations of its ratification.

The pact's approval followed fierce debates among Russian officials. Russia's foes of Kyoto, led by Putin's economic adviser Andrei Illarionov, warned that the pact would stymie the nation's economic growth. Kyoto backers rejected that claim, saying even after a five-year recovery, the post-Soviet economic meltdown has left emissions some 30 percent below the baseline.

Russian officials have voiced hope that the treaty will enable Moscow to attract foreign investment for its crumbling industries through provisions allowing countries to trade greenhouse gas emission allowances.

Under the treaty, Russia can sell unused emissions credits to countries that have exceeded their limits.

Once the deal takes effect, industrialized countries will have until 2012 to cut their collective emissions of six key greenhouse gases to 5.2 percent below the 1990 level. Greenhouse gases are believed to trap heat in the atmosphere, warming the Earth.

The next round of international climate talks is scheduled for next month in Buenos Aires, Argentina, and negotiations on curbing emissions after 2012 are due to start next year.

Russia's parliament has said that Moscow's decision on post-2012 emission cuts would be contingent on the outcome of those talks.