WMBD/WYZZ TV -- Cities around the world are going dark in an effort to go green. Earth Hour happens in every time zone at 8 p.m. on March 29.

The idea began last year with one city, Sydney, Australia, flicking off its lights for an hour to raise awareness of climate change. And in 2008, other cities are joining in.
 
This year, people in the Twin Cities are turning off all non-essential lights in observance of Earth Hour. Imagine Green Bloomington-Normal is spearheading the efforts there. Bloomington Mayor Steve Stockton and Normal Mayor Chris Koos are supporting the movement, as are Illinois State University, Illinois Wesleyan University, Heartland Community College, and State Farm.

Even if you miss Earth Hour this year, don't worry. You can take Environmental Action every day, just by remembering to turn of lights when you leave a room.