Did you remember to switch the lights off?

In 2007, the city of Sydney turned its lights off for one hour as a sign of support for urgent action on climate change. In 2008, hundreds of cities around the world joined in by switching off their lights. This year, thousands of cities have joined the symbolic movement. Have you? Please consider taking the first step at 8:30 PM on Saturday night. You're just one person, but there are over 6 billion like you.