World-famous landmarks including the Pyramids, the Eiffel Tower and Beijing's Forbidden City will go dark Saturday as millions turn out the lights for "Earth Hour", a rolling grassroots movement aimed at tackling climate change.
Now in its fourth year, the campaign promises to be the biggest yet with thousands of cities and towns in 125 countries - 37 more than last year - pledging to take part in the aftermath of a failed climate summit last year.
December's fractious Copenhagen summit has done nothing to dampen public hopes for meaningful action to avert catastrophic global warming, according to Earth Hour founder Andy Ridley.
"There appears to be some fatigue to the politics around it... But people are far more motivated this year than they were last year," he told AFP.
Now run by the WWF, Earth Hour began in Sydney in 2007 when 2.2 million people switched off the lights in their homes, offices and businesses for 60 minutes to make a point about electricity consumption and carbon pollution.
The campaign went global the following year, and this Saturday, more than 1,200 of the world's best-known landmarks will kill their lights at 8:30 pm local time in what organisers describe as a "24-hour wave of hope and action".
A raft of multinational companies including Google, Coca-Cola, Hilton, McDonalds, Canon, HSBC and IKEA have endorsed Earth Hour 2010 and pledged to darken their offices worldwide in support.
Sydney's iconic Harbour Bridge and Opera House will help kick off the energy-saving marathon, with Egypt's Pyramids and Sphinx, the Trevi Fountain and Tower of Pisa in Italy and all major landmarks in Paris to take part, led by a five-minute blackout of the Eiffel Tower.
Some 30 US states and municipalities were to mark Earth Hour with darkness falling on sites including Mount Rushmore, the Empire State Building, the Golden Gate Bridge and Seattle's Space Needle.
The Forbidden City in rapidly developing China, which was blamed by many activists for Copenhagen's failure, will go dark, along with the "Bird's Nest" Olympic stadium.
Elsewhere in Asia, where 3.3 million people have registered to take part, the world's biggest observation wheel, the Singapore Flyer, will extinguish its main lights, while official buildings will be blacked out in Seoul.
WWF Indonesia said around 200 buildings would take part in Jakarta.
Scores of cities in India were expected to participate, including the massive urban centres of Delhi and Mumbai, while the country's thriving Bollywood film studios were to shut down for the hour.
Japan's heritage-listed Hiroshima Peace Memorial, one of few buildings to survive America's 1945 atomic bomb attack, will take part, while major companies including Sony, Sharp and Asahi were to switch off across Tokyo.
And in Dubai, the world's tallest skyscraper, the Burj Khalifa tower, will also dim its lights.
Residents of Norway's Longyearbyen, the world's northernmost town, are set to brave an influx of curious polar bears normally deterred by lights after voting - for the first time - that participating was worth the risk.
"Earth Hour is meant to cross geographic, economic, country boundaries," said Ridley, admitting that it was mostly a symbolic act.
"It's one hour, one day, one year. We're not saving the planet by turning the lights off for one hour."
But he added: "What you are doing is adding your voice to a global call for action."Reuse content