This combo photo shows the general view of commercial buildings before (top) and after (bottom) turning off lights at Hong Kong's central district Saturday to mark the second worldwide Earth Hour. Over 1,700 buildings in Hong Kong join 2,800 municipalities in 84 countries in the event to highlight global climate change. (Vincent Yu / Associated Press)
Oriental Pearl Tower, left, tallest building, and Shanghai World Financial Center, right tallest, are darkened for one hour to mark Earth Hour in Shanghai, China. (Ji Chen / Associated Press)
People light the candles in the rain to mark the second worldwide Earth Hour, a global campaign to highlight the threat of climate change, in New Delhi, India. (Manish Swarup / Associated Press)
Young people hold candles marking the second worldwide Earth Hour, a global campaign to highlight the threat of climate change, in the Russian Far Eastern city of Vladivostok. (Associated Press)
A view of Rome's ancient Colosseum with its lights on prior to switching them off. (Gregorio Borgia / Associated Press)
A view of Rome's ancient Colosseum with its lights off. (Gregorio Borgia / Associated Press)
The Eiffel Tower is shown just after the 20,000 bulbs illuminating the tower went out. The City of Lights went dim when thousands of Parisians joined in an hour "lights-out" campaign. (Thibault Camus / Associated Press)
The ancient Giza Pyramids with lights on. (Nasser Nouri / Associated Press)
The pyramids gone dark. (Associated Press)
Acropolis floodlights are shown switched on in Athens. (Associated Press)
Acropolis floodlights are shown switched on in Athens. (Thanassis Stavrakis / Associated Press)
Photos from around the world as lights dimmed symbolically.
CHICAGO (AP) — From an Antarctic research base and the Great Pyramids of Egypt to the Empire State Building in New York, illuminated patches of the globe went dark Saturday for Earth Hour, a campaign to highlight the threat of climate change.