OTTAWA, Nov. 28 (Xinhuanet) -- About 10,000 environmentalists and officials from around the world gathered in Canada's Montreal on Monday for the first United Nations (UN) climate conference since the Kyoto agreement came into force in February.

    During the next 10 days, participants from 180 nations will brainstorm on how to slow the effects of greenhouses gases and global warming.

    The conference is considered the most important gathering on climate change since 140 nations ratified the Kyoto Protocol in 1997, which calls on the world's top 35 industrialized countries to cut carbon dioxide and other greenhouse gases emissions by 5.2 percent below their 1990 levels by 2012.

    The conference will also focus on what further action to take after 2012, when the Kyoto Protocol expires, although most signatories are already falling far short of their targets.

    The United States, the world's largest emitter of such gases, has refused to ratify the agreement, saying it would harm the U.S. economy and is flawed by the lack of restrictions on emissions by emerging economic powers such as China and India.

    Because of its refusal to ratify the treaty, the United States will take no formal part in discussions, but it has a place at the table because it is participant in the UN Framework Convention on Climate Change, the broader agreement which gave rise to the legally binding protocol.

    As host government, Canada is trying to find a formula which would enable the United States, other industrialized countries and the developing nations to unite under a combined statement on future action.

    But on the eve of the talks, the US chief negotiator Harlan Watson said he would strongly resist Canada's proposal, saying that it was premature to make any further commitments under the UN Framework Convention on Climate Change.

    Meanwhile, the European Union appears to be taking the lead, endorsing a plan in June to bring emissions of greenhouses gases down 15 percent to 30 percent below 1990 levels by 2020.

    The conference comes amid new research showing there is now more carbon dioxide in the atmosphere -- a major contributor to greenhouse gases -- than at any point in the last 650,000 years.

    The study by the European Project for Ice Coring in Antarctica, published earlier this month in the journal Science, analyzed tiny air bubbles preserved in Antarctic ice for millennia.

    It also found that the Earth's average temperature has increased about 1 degree Fahrenheit in recent decades, a relatively rapid rise. Enditem