Russia all but ratified the treaty Thursday, lending it the support needed for passage.
After years of wavering, the Kremlin announced Thursday it will throw Russia's decisive vote behind the 1997 Kyoto climate change treaty, making it likely that its tough curbs on carbon dioxide emissions - which the US has decried as a brake on economic growth - could become global law within months.
"The fate of the Kyoto Protocol rests upon Russia," Deputy Foreign Minister Yury Fedotov told the cabinet meeting that decided to send the pact to the State Duma for ratification by year's end. "If we rejected its ratification, we would become the ones to blame," he said.
Under the deal, industrialized countries responsible for 55 percent of the world's carbon dioxide pollution - caused by burning fossil fuels in industries, power stations, and automobiles - must reduce their emissions by just over 5 percent by 2012.
So far 124 countries representing 44 percent of emissions have ratified the deal, while the US and a few other growth-first states have refused to join. That left Russia, accounting for 17 percent of the world's carbon pollution in Kyoto's base year of 1990, holding the power to make or break the deal.
The Russian move has been applauded by environmentalists, who regard Kyoto as essential to efforts to reverse global warming. "This is a very good step, and we welcome it," says Ivan Blokov, a spokesman for Greenpeace-Russia. "We already see very clear signs of climate change occurring, and the problem is becoming more urgent every day."
Russian oil companies launched a major public relations drive last year to dissuade the Kremlin from backing Kyoto, and the prestigious Russian Academy of Sciences issued a report arguing that the treaty would hamper Russia's plans for post-Soviet economic revival.
Opponents of Kyoto complain the treaty discriminates against economically depressed post-Soviet Russia by treating it as the industrially developed USSR in 1990, while rapidly growing China, as a developing country, is subject to no emission restraints at all.