The lights of the Empire State Building went dim Saturday for Earth Hour.
New York City's iconic skyscraper went dark from 8:30 p.m. to 9:30 p.m. to bring attention to climate change.
Landmarks across the globe, including the Eiffel Tower and the Acropolis, are dimmed at 8:30 p.m. local time.
Earth Hour began in Syndey in 2007 and spread worldwide under WWF.
This year, people are also encouraged to "go dark" on their Facebook page.