Updated

Russia's Cabinet approved the Kyoto Protocol (search) on global warming Thursday, clearing the way for the worldwide adoption of the pact — despite U.S. opposition — once the Russian parliament ratifies it as expected.

The protocol must be ratified by no fewer than 55 countries that accounted for at least 55 percent of global emissions in 1990.

Without Russia's support, the U.N. agreement, which has been rejected by the United States, cannot come into force. Washington says the treaty puts a disproportionate burden on the American economy and favors developing nations.

The 1997 Kyoto protocol calls for industrialized countries to cut their collective emissions of six key greenhouse gases (search) to 5.2 percent below the 1990 level by 2012 in an effort to slow global warming. If a country exceeds the emissions level, it could be forced to cut back industrial production.

The European Union (search) has long urged Russia to ratify the pact. In May, President Vladimir Putin (search) pledged to speed up approval in return for EU support of Russia's bid to join the World Trade Organization (search).

But many of Putin's advisers opposed, arguing that joining Kyoto would stymie Russia's economic growth and put Putin's goal of doubling gross domestic product in a decade out of reach.

The United Nations and the EU greeted the Russian endorsement.

"Russian ratification of the Kyoto Protocol is the final step needed to bring this crucial treaty on climate change into force," said Klaus Toepfer, executive director of the United Nations Environment Programme.

"The news today that the Government of Russia has endorsed the Protocol and will present it to the Duma, the Russian parliament, is cause for celebration."

A Russian government official speaking on condition of anonymity said the bill would be submitted soon to the lower house of parliament, or State Duma, so the treaty can be ratified before year's end.

The Duma is dominated by the Kremlin-directed United Russia party and approval is almost certain.

Konstantin Kosachev, the powerful head of the Duma's foreign affairs committee, said lawmakers would be guided primarily by economic considerations.

"The economic factor would have a decisive role, environmental considerations would come second and political expediency would matter less," Kosachev said.

He would not say when the pact might come to vote but said his committee likely would complete preparations for the ratification debate before Dec. 31.

The treaty would take effect 90 days after being ratified by Russia.

"Ratification will remove many irritants in our relations with the EU," Kosachev said. "From the political viewpoint, I have always supported ratifying this pact."

However, some government officials remain critical of Kyoto.

Russian Prime Minister Mikhail Fradkov said during a trip to the Netherlands on Thursday that the Duma would likely have a "difficult debate" on the document — a statement that appeared to signal that Russian officials are still divided on the issue despite the Cabinet's support of the bill.

Putin economic adviser Andrei Illarionov voiced his opposition at the Cabinet meeting.

"It's a political decision, it's a forced decision," Illarionov said, according to the Interfax news agency. "It's not the decision we are making with pleasure."

UNEP's Toepfer said the recent series of hurricanes that have devastated the Caribbean and parts of the United States demonstrate that reducing emissions is even more urgent now than when Kyoto was signed in 1997.

"These kinds of natural disasters, with their appalling loss of life and significant economic costs, are likely to become even more frequent and extreme unless global warming is effectively checked," he said in a statement.

The EU welcomed Russia's endorsement and said it now hoped the U.S. administration would drop its objections.

"This is a very welcome event," EU spokesman Reijo Kemppinen said, adding that the EU hopes the United States "will reconsider" its position.

Some observers have speculated that Russia is jockeying for more favorable terms when rules are worked out for a mechanism under which countries that come in with emissions levels below the targets can sell pollution credits.

In its decision Thursday, the Cabinet said government ministries and agencies should come up with proposals on how best to fulfill Russia's obligations under the pact.

Russia's emissions have fallen by about a third since 1990, largely because of the post-Soviet industrial meltdown. But pollution has started to rise again because of an economic revival in recent years.