On Saturday, March 29 at 8 pm local time, the conservation group World Wildlife Fund is encouraging people around the world to turn off lights for one hour. Planners of the event, called “Earth Hour,” bill it as a way not only to reduce greenhouse gas emissions by reducing electricity demand for an hour, but to draw attention to the kinds of personal actions people can take to reduce GHGs. So far, individuals, municipalities, institutions, and businesses from around the globe have signed up on the Earth Hour Web site, including seven businesses and schools from Kentucky. Some major cities are also participating, like Sydney, Australia, San Francisco, and Chicago. In the Windy City, “Signature skyscrapers, key landmarks, theater marquees and shops on the Magnificent Mile will voluntarily turn off their lights.” Louisville, so far, hasn’t signed up.