NAIROBI, Kenya − Russia formally notified the United Nations on Thursday of its acceptance of the Kyoto Protocol on global warming, starting a three-month countdown for the long-debated 1997 pact to come into force.

Russian President Vladimir Putin signed the protocol into law earlier this month, allowing it to take effect in 128 nations that ratified it even as the United States has refused to join, said Eric Falt, spokesman for the U.N. environmental agency.

On Thursday, Russia's permanent representative to the United Nations, Andrey Denisov, turned over the accession documents to U.N. Secretary-General Kofi Annan in the Kenyan capital, Nairobi, where the U.N. Security Council is holding a rare meeting outside its New York headquarters.

"I congratulate President Putin and the Russian Federation for their leadership in making it possible for the protocol to enter into force -- as it will, 90 days from tomorrow on Feb. 16, 2005," Annan said. "This is a historic step forward in the world's efforts to combat a truly global threat."

The protocol, ratified by both houses of Russia's parliament last month, commits 55 industrialized nations to making significant cuts in emissions of gases like carbon dioxide by 2012.

Developing nations like Brazil, China, India and Indonesia are also parties to the protocol but do not have emission reduction targets.

The United States and Australia have rejected the pact, which Putin signed on Nov. 4 and which could not have come into effect without Russia, which accounted for 17 percent of carbon dioxide emission in 1990. The United States accounted for 36 percent of carbon dioxide emissions in 1990.

Russia joined the protocol because the commitment would press the country to modernize its economy and protect the environment, the country's foreign ministry said in Moscow.

The country ratified the pact after "calculating the significance of the protocol for the development of international cooperation," the ministry said in a statement. "This document was only able to come into force on the condition of our participation in it."

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.

"We need to make fighting climate change part of a broad church in which all facets of society are brought on board," said Klaus Toepfer, the U.N. environmental chief.

"A period of uncertainty has closed. Climate change is ready to take its place again at the top of the global agenda," said Joke Waller-Hunter, head of the Climate Change Secretariat, which services the U.N. Climate Change Convention and its Kyoto Protocol.

Scientists have already detected many early signals of global warming, including the shrinking of mountain glaciers and Arctic and Antarctic sea-ice, reduced ice cover on lakes and rivers, longer summer growing seasons, changes in the arrival and departure dates of migratory birds, as well as the spread of many insects and plants toward the poles.

Africa, which is only responsible for just over 3 per cent of greenhouse gas emissions, is likely to be hit hardest by the impacts of climate change.

"We need the active engagement of the rapidly developing economies of China and India so that their development, involving a third of the world's population, is propelled on a cleaner and less carbon-intensive path," Toepfer said.

Source: Associated Press