MOSCOW -- In what would be a mortal blow to the accord aimed at halting global warming, a top Kremlin official said Tuesday that Russia won't ratify the Kyoto Protocol limiting greenhouse gas emissions because it will hurt the country's economy.
The United States rejected the accord for the same reason. Without Moscow, the protocol cannot come into effect even if approved by every other nation because only Russia's industrial emissions are large enough to tip the balance.
The pollution cuts required by the treaty would slow the economic growth that President Vladimir Putin has made a major priority, said top adviser Andrei Illarionov.
"The Kyoto Protocol places significant limitations on the economic growth of Russia," Illarionov told reporters in the Kremlin on the sidelines of Putin's meeting with European business leaders. "Of course, in its current form this protocol can't be ratified."
Earlier this fall, Putin cast deep doubts on Moscow's willingness to ratify the protocol, but he had not ruled it out entirely.
Illarionov said it would be unfair for Russia to curb emissions and stymie its own growth while the United States and other nations, which account for the bulk of global emissions, refuse to join the pact.
Putin laid out Russia's objections in what Illarionov called a "very energetic" discussion with the European industrial leaders.
The Kyoto Protocol, signed by many of the world's nations at a conference in Japan in 1997, sets targets for countries to reduce emissions of carbon dioxide and other greenhouse gases, which are seen as a key factor behind global warming.
To take effect, the pact requires ratification by a minimum of 55 countries, which must include the industrialized nations that accounted for at least 55 percent of that group's carbon dioxide emissions in 1990.
So far, industrialized nations that have signed on account for 44.2 percent of the 1990 emissions. Russia accounts for 17.4 percent, so its ratification would push the group over the top.
Attention focused on Russia after the Bush administration announced it would not ratify what it called a flawed pact that would unfairly harm the U.S. economy. The United States is responsible for one-fourth of the world's man-made carbon dioxide emissions, and its March 2001 decision angered environmentalists.
Russian officials initially suggested Russia would ratify it, but remarks by Putin and Illarionov at a climate-change conference in Moscow two months ago indicated the opposite.
Putin has called for the doubling of Russia's gross domestic product by 2010 -- a goal officials fear might conflict with the Kyoto Protocol, which would require the Kremlin to overhaul Russian industries to cut emissions.
Russia's emissions have fallen by 32 percent since 1990 amid the post-Soviet industrial meltdown, but they have slowly started to rise with the economic revival of the past five years.
Putin puzzled his audience at the Moscow conference this fall by remarking that Russians "could spend less on warm coats" if the country warmed up by a few degrees, while Illarionov questioned the pact's feasibility and scientific foundation.
At a climate change conference that began Monday in Milan, Italy, the news from Russia left participants pondering strategies in the absence of a global treaty.
Steven Guilbeault of Greenpeace said Illarionov's remarks appeared to be "a political comment" ahead of Sunday's elections for the State Duma, Russia's lower house of parliament.
Philip Clapp, president of the National Environmental Trust, an advocacy group based in Washington, also mentioned the elections and pointed out that Illarionov has been one of Russia's strongest critics of the protocol.
Clapp speculated that Moscow might be jockeying for more favorable terms when rules are worked out for a mechanism under which countries that are under emissions target levels can sell credits to nations that still need to reduce.
Putin and other officials often make fiery comments meant largely to show Russians that the Kremlin is standing firm against foreign pressure, but the Kyoto Protocol is not seen as a key issue for Russian voters.
The European Union, which has led the fight to save the pact after Washington pulled out, said in a progress report it was getting further from meeting its own targets for greenhouse gas emission reductions under the pact.
The European Environment Agency said its latest figures were "much more pessimistic" than last year's mainly because Germany drastically scaled back its forecast for reductions.
"At the moment things are moving away from Kyoto rather than toward it," said spokesman Tony Carritt.