have been marking earth hour by switching off their lights from the sydney opera house to the empire state building in new york skyliners have been or will be a little darker as the event moves through the time zones earth hour is aimed at sparking global awareness about environmental issues take a look. at light site in moscow is rate square. as the eiffel tower disappears from the paris style a. at eight thirty pm local time in cities of right in the world stopped eliminating their landmarks and turned the lights for air thyra it's part of a call for international unity for action on climate change and last just sixty minutes taking place each year for more than a decade it all started in sydney which was also one of the first cities to go black the world wide fund for nature created the event to urge people to think