世界各地熄灯响应"地球一小时"

A combination photo shows the Sydney Harbour skyline before (top) and during Earth Hour (bottom) March 27, 2010. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. [Agencies]