Last year, more than 2.7 million Illinois residents helped the lights of Chicago's iconic skyline -- and lights in communities across the state -- dim for one hour: Earth Hour.

The Windy City returns as a flagship city for Earth Hour 2009, during which households, organizations, and businesses across Illinois are encouraged to turn off their lights and turn their attention towards the need for substantial, long-term action to raise awareness about energy efficiency and global climate change.

Homes, businesses, organizations, and landmarks throughout the Chicagoland area and across the state, the nation, and the globe. New activities and events surrounding Earth Hour 2009 are announced each day. Visit www.EarthHourUS.org/Chicago for the latest participating locations and community updates.