Earth Hour 2008 Join Earth Hour 2008 on March 29th 3/29/2008 Join Earth Hour's 2008 Global Movement on March 29th, 2008.  In 2007, over 2 million people in Sydney, Australia joined Earth Hour's climate change efforts by turning off their lights for one hour.  According to Earth Hour, "If 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, Earth Hour is taking their movement global! To participate on March 29th, 2008 sign up at www.earthhour.org.