Former U.S. Vice President Al Gore testifies about global warming during a hearing held by the House Energy and Commerce Committee on Capitol Hill in Washington March 21, 2007. (Xinhua/Reuters Photo) Photo Gallery>>>

    BEIJING, March 22 (Xinhuanet)-- Al Gore, former U.S. vice president, on Wednesday took his campaign against global warming to Capitol Hill, stressing the need for quick action.

    Fresh off a triumphant Hollywood appearance in which his climate-change documentary, "An Inconvenient Truth," won two Oscars, Gore drew overflow crowds as he testified before a joint panel, terming the current climate crisis: "Our world faces a true planetary emergency."

    Gore discussed the risks of sea level rise, stronger storms, more wildfires and other ills associated with global climate change, and urged an immediate freeze on U.S. carbon dioxide emissions.

    At the House hearing, he was flanked by cardboard boxes that he said contained some 516,000 letters calling for congressional action to stop global warming.

    "This problem is burning a hole at the top of the world in the ice cover that is one of the principle ways our planet cools itself," Gore said. "If it goes, it won't come back on any timescale relevant to the human species."

    Gore, who brought with him a half-million signed petitions for action, wanted a freeze on greenhouse gas emissions followed by mandatory reductions of 90 percent by 2050.

    He said the U.S. should push a new international climate change treaty after rejecting the 1997 Kyoto protocol that requires 35 industrial nations to cut greenhouse gases. The Bush administration argues Kyoto would hurt the U.S. economy.

    Gore advised lawmakers to cut carbon dioxide and other warming gases 90 percent by 2050 to avoid a crisis. Doing that, he said, would require a ban on any new coal-burning power plants -- a major source of industrial carbon dioxide -- that lack state-of-the-art controls to capture the gases.

    He said he foresees a revolution in small-scale electricity producers for replacing coal, likening the development to what the Internet has done for the exchange of information.

    "There is a sense of hope in this country that this United States Congress will rise to the occasion and present meaningful solutions to this crisis," Gore said. "Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it's a challenge to the moral imagination."

    Gore has lately faced public questions about his personal "carbon footprint," especially at his home in Tennessee. An aide noted that Gore and his wife Tipper drove to Wednesday's hearing in a black hybrid vehicle.

(Agencies)