These two photos show the lights being turned off at Malaysia's landmark Petronas Twin Towers to mark Earth Hour in downtown Kuala Lumpur, Saturday, March 28, 2009. In more than 4,000 cities around the world, lights were turned off for one hour at 8:30 p.m. local time, as part of a global campaign to highlight the threat of climate change.
Credit: AP Photo/Lai Seng Sin
In Manila, people wave their glow sticks after switching off lights. Last year's Philippine Earth Hour amounted to energy savings equivalent to shutting down a coal power plant for one hour. This year an estimated 10-15 million Filipinos joined in.
Credit: AP Photo/Pat Roque
Traffic lights are seen in a time-lapse photograph surrounded by buildings with non-essential lights switched off, at Connaught Place in the heart of New Delhi, Saturday, March 28, 2009.
Credit: AP Photo/Gemunu Amarasinghe
In Melbourne, people ride push bikes fitted with custom-made electric generators, Saturday, March 28, 2009. Throughout the past week, participants in "Future Spark" generated enough power to run a free open-air concert tonight, which boasted it was all powered by people.
Credit: AP Photo/Rob Griffith
Visitors view the "Bird Nest" National Stadium which has been darkened for one hour to mark Earth Hour in Beijing, March 28, 2009. Of the 88 countries participating in Earth Hour this year, more than half are developing and emerging economies, whose energy use has been a critical factor in current negotiations to limit greenhouse gases.
Credit: AP Photo/Ng Han Guan
Moscow State University is darkened, while in the Russian city of Vladivostok -- some 5,750 miles to the east -- young people hold candles marking the second worldwide Earth Hour, Saturday, March 28, 2009.
Credit: AP Photos
A view of Rome's ancient Colosseum with its lights off during the Earth Hour event, Saturday, March 28, 2009.
Credit: AP Photo/Gregorio Borgia
The presidential guard changes in front of the Greek Parliament where the lights have been dimmed during Earth Hour in Athens, on Saturday March 28, 2009.
Credit: AP Photo/Thanassis Stavrakis
The City Of Lights
The Eiffel Tower is shown just after the 20,000 bulbs illuminating the tower went out Saturday, March 28, 2009 at 8.30 p.m. The lights were extinguished for only five minutes for security reasons, because visitors are on the tower, but a nightly 9 p.m. "sparkling lights" feature will not run.
Credit: AP Photo/Thibault Camus
The Ericsson Globe Arena "disappears" during Earth Hour in Stockholm, Saturday, March 28, 2009.
Credit: AP Photo/Scanpix, Anders Wiklund
A night view of the ancient Giza Pyramids during Earth Hour, in Cairo, Saturday, March 28, 2009.
Credit: AP Photo/Nasser Nouri
A general view of the Houses of Parliament in London, taken with a long exposure.
Credit: Press Association via AP Images
Tamara Kipic and Monique Plucsinski enjoy Sushi dinner by candlelight for Earth Hour at Oishii restaurant in Windsor, Saturday, March 28, 2009.
Credit: AP/Dave Chidley, The Canadian Press
Signage in Times Square is dark during Earth Hour 2009, sponsored by World Wildlife Fund.
Credit: AP Photo/Stephen Chernin
President Michelle Bachelet, surrounded by candles, speaks at the La Moneda presidential palace in Santiago, Saturday, March 28, 2009, Saturday, 2009.
Credit: AP Photo
Downtown Chicago is darkened during Earth Hour 2009 on Saturday, March 29, 2009. The Wrigley Building is seen at center.
Credit: AP Photo
The Angel of Independence monument sits in darkness during the Earth Hour in Mexico City, Saturday, March 28, 2009.
Credit: AP Photo/Marco Ugarte
A group participates in a special candle-lit Earth Hour Yoga class at East Side Yoga in Windsor on Saturday, March 28, 2009.
Credit: AP Photo
The hour-long unplugging saw most decorative lighting and some casino signs of the city go dark, along with the famed "Welcome" sign and the Fremont Street Experience, an overhead canopy of lights downtown.
Credit: AP Photo/Isaac Brekken