It may not sound like a classic Saturday night blow-out, but at 8 p.m. on March 29, millions of people around the world will turn off their lights to celebrate Earth Hour. This event, sponsored by the WWF, a global conservation organization, is intended to increase awareness of global warming and spur action to combat the issue. The movement began last year when the WWF asked residents of Sydney, Australia, to turn off their lights for an hour. So on March 31, 2007, 2.2 million people and 2,100 Sydney businesses turned off their lights. Even icons such as the Harbour Bridge and the Sydney Opera House went dark. Electricity in many cities and countries is powered by coal-fired plants that produce carbon dioxide, the most important greenhouse gas that human activities emit into the atmosphere. The WWF estimates that if the greenhouse gas reduction achieved during the Sydney Earth Hour was sustained for a year, it would be equivalent to taking 48,616 cars off the road for a year. The event has expanded this year to include cities in other countries, such as the United States, Canada, Denmark, Israel and Thailand. Chicago will serve as the U.S. flagship city for the event, with Atlanta, Phoenix and San Francisco joining it as leading partners in the endeavor. Individuals can sign up to participate on the Earth Hour site — so far 240,000 people have signed their support of the event. Celebrities such as singer/songwriter Nelly Furtado and the band Fall Out Boy have pledged to turn out their lights, as have the Phoenix Suns and Chicago Cubs.

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