In 2007, Sydney, Australia, cut the power for 60 minutes as a way to raise awareness about global warming. Call it a token gesture, but just that one small act alone slashed the city’s emissions by 10%. According to Earth Hour‘s website:
[I]f the greenhouse reduction achieved in the Sydney CBD during Earth Hour was sustained for a year, it would be equivalent to taking 48,616 cars off the road for a year.
This year, 370 cities worldwide took the pledge; and now Earth Hour 2008 has come and gone. Was it a success? While results seemed a little mixed, one thing is for sure: Sydney and Manila both earned gold stars. Just take a look at Boston.com’s photo gallery:

[photo courtesy the Associated Press]
Inspiring, no? And the Earth Hour Flickr pool is filling up with some equally dramatic photos. (Way to go, Seattle!)
Even Google got in on the act.

[photo courtesy pirate johnny]
OK, I worry that this post might be coming off as a bit breathless … but after seeing environmentalist Bill McKibben speak at D2E Boston, it’s hard not to be all fired up about climate change. Yesterday, McKibben dropped this sobering statistic: NASA researchers recently concluded that the maximum safe atmospheric concentration of carbon dioxide is roughly 350 parts per million. And we shot past that benchmark 20 years ago — we’re at 385 ppm right now.
McKibben offers this analogy: Let’s say your doctor tells you that your cholesterol is dangerously high. Sure, you may not be doubled over with a heart attack right this second, but unless you’re looking to become a young, well-marbled corpse, McKibben says, “you have to stop eating cheese.” Consider Earth Hour a slice of cheese not eaten.
McKibben’s latest effort is 350.org, a global-warming activist movement still in its infancy. Check it out!