First the lights went out in Christchurch, New Zealand, at 8 p.m., on March 31, and then one by one city and small town lights around the globe followed suit. The lights-out was known as Earth Hour, an event organized by the World Wildlife Fund (WWF)-Australia) last year and taken global this year. It aims to show governments that communities care about climate change and want decisive action.

It is estimated that cities in 35 countries in 14 time zones took part in the event, which wrapped up in San Francisco. Landmarks and other electricity-using establishments joined in. Google turned its normal white homepage black; Prince Charles dimmed the lights at his private residence in England; and Casey Station in Antarctica went dark.

 You can sign up now for Earth Hour 2009 at http://www.earthhour.org/ as an individual, organization, school or business.