The World Wildlife Fund is asking people to turn off their lights tonight for Earth Hour, a world-wide event to raise awareness about global warming. Cities around the globe will flip the switch from 8:30 p.m. to 9:30 p.m.  Seattle will join in with the Space Needle, Pacific Science Center, Seattle Municipal Tower and the “City Light” sign at Fourth Avenue and Spokane Street going dark.

Organized by the World Wildlife Fund, Earth Hour began in Syndey, Australia, in 2007.