An Italian environmentalist, wearing a teargas mask Feb. 15, protests in front of Rome's U.S. Embassy with placard in six languages marking the implementation of the Kyoto Protocol on global warming which will become effective Feb. 16. (AP)

The United Nations Kyoto Protocol on global warming went into effect Wednesday with most of the industrialized countries legally bound to control pollution.

The international treaty aiming at curbing emissions of greenhouse gases finally realized its implementation eight years after it was negotiated in Japan's ancient city Kyoto in 1997 by 159 countries and ratified by 141 nations. It is an adjunct to the1992 UN treaty on climate change.

The pact, known officially as the United Nations Framework Convention on Climate Change (UNFCCC), came into force at 0500 GMTWednesday or midnight Tuesday in New York, where the United Nations is headquartered.

The protocol targets carbon dioxide and five other gases that can trap heat in the atmosphere, and are blamed for rising global temperatures that are melting glaciers.

The protocol will have legal force for its participants from Feb. 16 after meeting twin conditions -- backing from at least 55 countries and support from nations representing at least 55 percent of developed countries' carbon dioxide emissions.

It passed the second hurdle in November 2004 when ratified by Russia and now has backing from nations representing 61.6 percent of emissions. But the United States, the world's biggest polluter,withdrew from the Kyoto treaty in 2001 with an excuse that the treaty would cause adverse effects on the US economy and wrongly omits developing nations.

The protocol commits the industrialized countries who have ratified it to reduce the amount of six greenhouse gases (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6)) by 5.2 percent of 1990 levels during the five-year period 2008-2012.

Only 39 countries have target levels for the 2008-2012 period, adhering to the principle set under the UNFCCC that richer countries should take the lead.

Japan is required to reduce its carbon dioxide and other greenhouse gas emissions by 6 percent from the 1990 level.

But local environment experts pointed out that the pact, however, remains a small step, as it covers only a third of total emissions in the world.

Japan is expected to have difficulty achieving its target as its emission of such gases in fiscal 2003, which ended March 31, 2004, was up 8 percent from the 1990 level, the expert said.

The ratification in November by Russia, which accounted for 17.4 percent of carbon dioxide emissions in the base year 1990, pavedthe way for the pact to come into effect. The pact requires ratification by 55 nations accounting for at least 55 percent of emissions in 1990.

Under a 2001 deal made by environment ministers in Germany, countries overshooting their targets in 2012 will have to make both the promised cuts and 30 percent more in a second period from2013.

The occasion of the inauguration of the world's first attempt to control climate change was marked around the world.

In Bonn, Germany, the secretariat of the UN framework convention and civic groups will jointly hold a commemorative event.

In Japan, a symposium will be held Wednesday evening in Kyoto, where Kenyan Deputy Environment Minister Wangari Maathai, the 2004Nobel Peace Prize laureate, is scheduled to give a keynote speech.

According to Kyodo News, UN Secretary General Kofi Annan and European Commission President Jose Manuel Barroso will send congratulatory messages through a video conference system.

In addition, given the expected limited impact of the pact, theKyoto Protocol supporters are already looking beyond it and have begun discussing post-pact policies for 2013 and onward.

The key issues for the post-2012 steps will include how to win US support for the new policies, and to re-examine the obligationsand commitments to curb the greenhouse gas emissions in developingcountries, which are exempted from the treaty's obligations.