The Taipei 101 building in Taiwan, currently the tallest building in the world (but not for long), turns out its lights for Earth Hour 2009.

On March 29th, people from around the world turned off lights for Earth Hour 2009. 4,085 cities and 88 countries participated in the event, which is being described as the largest demonstration of public concern about climate change in history. Check out these pictures of international cities, monuments, and landmarks before and during Earth Hour. The lights on and lights off versions of each photograph are overlaid and will alternatively morph into each other if you click the picture. It’s a cool effect that lets you identify exactly where lights were off and what kind of difference they made.

Where were you and what were you doing during Earth Hour? Did you participate? I was on a train on the way into New York City, so I not only didn’t have any [of my own] lights on, but I was also using public transportation, an earth-friendly alternative to cars (OK, it was kind of by necessity, but still…).

In 2007, 2.2 million homes and businesses in Sydney, Australia turned off their lights for one hour to show their commitment to planet earth. In 2008, the message grew into a global sustainability movement, and approximately 50 million people around the world turned off their lights for Earth Hour. This year, Earth hour, with the support of WWF, hopes to attract over 1 billion participants who will turn off their lights for one hour, from 8:30PM to 9:30PM local time, on Saturday, March 28, 2009. They’re treating it like a vote – switching off your lights is a vote for Earth, leaving them on is a vote for global warming – which I think is kind of lame, but it’s an awesome cause anyway, meant to bring attention to the green movement, sustainability, the importance of protecting our planet, etc. I’ll be participating, and you should too (sign up here). If this works, I bet it would be awesome to watch from space, like “the wave” at a football game except with a big band of darkness slowly making its way across the surface of the earth. Hopefully, they’ve got some kind of satellite up there videotaping it…