This weekend, buildings across the globe will turn off their lights at 8 p.m. on Saturday night in recognition of Earth Hour, a campaign to encourage people to conserve energy. The event, created by the World Wildlife Fund in Australia last year, led 2.2 million Sydney residents to flick off their switches, resulting in a 10.2% reduction in energy output for the hour. This year, Earth Hour is going global, and over 200 cities worldwide are planning to participate. The National Geographic building in D.C. will naturally be taking part (the NG Channel is the U.S. media sponsor, after all), turning off our exterior and interior lights. But the event isn't limited to just skyscrapers and office towers; lights will go out in hundreds of other places, from the Golden Gate Bridge in San Francisco, to the golden arches at McDonald's restaurants throughout Canada.
You can do your own part by turning off your lights at 8 p.m., and WWF has plenty of ideas for ways to spend your time in the dark.
Photo: National Geographic Society headquarters, Photo by Mark Thiessen