Lights Go Out Tomorrow for Earth Hour Cities across the world flick switches at 8:30pm By John Johnson, Newser Staff Posted Mar 26, 2010 12:53 PM CDT 23 comments Comments Buildings in downtown Chicago go dark during last year's Earth Hour. (AP Photo/Commonwealth Edison, Eric Y. Exit) (Newser) – Earth Hour returns tomorrow night, with cities across the world turning off the lights at 8:30pm local time. The annual event sponsored by the World Wildlife Fund is in its fourth year and growing quickly. About 30 US state capitals are expected to take part, up from 8 last year. Lights will go down at the Empire State Building, the Golden Gate Bridge, and the Las Vegas Strip, notes USA Today. "It reflects the conviction of people around the world that climate change is real, and we need to do something about it," says the CEO of the WWF.