Just one hour

What difference can an hour make? You'd be surprised -- when 2.2 million residents and 2,100 businesses in Sydney, Australia, all turned off their lights for an hour in 2007, they reduced energy use by 10.2% that day. That's equivalent to taking 48,000 cars off the road.

Just by turning off the lights for 60 minutes. It was the first Earth Hour, sponsored by several Australians and the World Wildlife Fund.

This year, they've taken the idea global, and Earth Hour will be celebrated on Saturday, March 29, 2008, from 8 p.m. to 9 p.m., with more than 20 cities officially participating.

More important than just the energy saved is the idea that one person's actions really do have an affect on global warming. The little things add up when we're all involved. Conserving resources, lowering pollution -- each of us can make an impact by doing things as basic as turning off a light.

To encourage individuals to get involved, many world landmarks are joining the Sydney Opera House in shutting off non-essential lights on Saturday. San Francisco's Golden Gate Bridge will go dark. The Sears Tower in Chicago, plus both Wrigley Field and Soldier Field will dim. Toronto's CN Tower will go dark, and even Niagara Falls won't be lit up during Earth Hour. The Coca Cola headquarters in Atlanta is turning off the lights. And in the Philippines, the world’s third largest mall is flicking the switch.

Your city doesn't have to be going totally dark for you to join in. Sign up at the Earth Hour site so organizers have an idea of how many people are involved. Tell your friends and neighbors.

Then simply turn off lights in your home from 8 p.m. to 9 p.m. on Saturday night. Enjoy the dark, or break out your beeswax or soy candles and have a romantic dinner with someone special. Play a board game by candlelight with the family. Take a walk with a friend or your dog. Soak in a bathtub with candles nearby.

Looking for more adult ways to enjoy the dark? Check out the Daily Green's list of eight sexy ways to spend Earth Hour. Earth 911 even offers lights-out fashion tips, such as glow-in-the-dark gear and shiny bling.