This WWF campaign started in 2007 in Sydney as a kind of public statement on climate change:
"By voting with their light switches, Earth Hour participants send a powerful, visual message demanding action on climate change," WWF says on the Earth Hour Web site.
Since then, Earth Hour has become a global movement, with more than 4,000 cities in 87 countries going dark for 60 minutes last year. (See pictures of Earth Hours past.)
Clearly the main thrust of Earth Hour is to remind folks that we use a heck of a lot of energy to brighten offices, illuminate landmarks, and advertise Broadway hits—and all that energy consumption equals quite a few greenhouse gas emissions.
But there's another form of pollution of which Earth Hour participants can easily be made aware: light pollution.
Look at Brisbane Night, before and after "Earth Hour"
Before
After
Look up the sky!! different???
(Source : NatGeo)
