At 8 p.m. Saturday citizens of Atlanta will join millions of people around the world in turning off nonessential lights for one hour. Earth Hour is a bold statement in support of action on climate change. On this historic evening, the city of Atlanta will demonstrate to the world how, by working together, each of us can begin to make a positive impact on this global issue.

Many will hear about this initiative and question why we are doing it. And while people may disagree about issues involving the environment, this event will at the very least open a dialogue and let us air our opinions for discussions on solutions for environmental problems we face today and in the future.

It also gives us an opportunity to talk with friends, families and co-workers about ways we can work together to conserve energy and natural resources. One of the goals of Earth Hour is to have participants commit to longer-term benefits, such as replacing older lights bulbs throughout their homes with highly efficient compact fluorescents, and to commit to reducing energy consumption on a daily basis.

The United States is the world's leading emitter of carbon dioxide —- more than 20 tons per person every year —- from sectors ranging from energy to agriculture to transportation. While there are many reasons for the U.S. leading in this category —- the size of our economy, goods and services produced, etc. —- efficiency must be a key component of any legitimate climate strategy. Individuals accomplish efficiency, and Earth Hour is a way you can participate.

The complex global issue of climate change is perhaps one of the largest challenges we face, and it won't easily be solved by individuals acting on their own or by reducing energy use for just one hour of the year. It will take the collective action of many people coming together to show they care about the type of world we want to pass on to future generations.

Earth Hour 2008 is just a first step. On the night the lights go out in Georgia, don't be left in the dark.

We encourage everyone to sign up at EarthHour.org, turning off their lights from 8 to 9 p.m. Saturday and by committing to reducing energy consumption and living a more sustainable lifestyle.

One person can begin to make a difference, and millions of us working together can change the world.

> Carter Roberts is the president and CEO of World Wildlife Fund, organizer of Earth Hour: www.earthhour.org.