You are invited to join thousands of your Chicago friends, neighbors and businesses and millions of people around the world to make a bold statement about climate change on March 29 from 8 to 9 p.m local time.

Turn out your lights for one hour. Earth Hour.

As World Wildlife Fund's flagship city for the United States, Chicago, a leader in environmental initiatives, is encouraging its residents across the region to make the pledge to help fight global warming by voluntarily turning off their lights for 60 minutes. Signature skyscrapers, key landmarks, theater marquees and shops on the Magnificent Mile will voluntarily turn off their lights.

Earth Hour's not just about cutting back for one hour. It's about taking a stand and thinking ahead about what you, your neighbors and your city can do to slow climate change.

Seize the Earth Hour moment and change some of your outdated energy-wasting light bulbs to new, efficient and inexpensive compact fluorescents. Think of other ways you can cut your energy usage and trim your electric bill after Earth Hour has passed.

Other ways to celebrate: host a candlelight cocktail party, go camping, plan a scavenger hunt in the dark for your kids.

One hour, Chicago. Earth Hour.