Check out Earth Hour across the globe

This combination of photographs shows China's National Stadium, known as the Bird's Nest, with the lights on and with the lights off during the annual Earth Hour event in Beijing, Saturday. Millions of people were expected to switch off their lights for Earth Hour, in a global effort to raise awareness about climate change that was even to be monitored from space.

This combination photograph shows buildings in Jakarta's business district, with the lights on and off during the annual Earth Hour event.

In a long exposure image, the Sydney skyline shines bright, after Earth Hour, from Milson's Point, Australia. Sydney residents turn off their lights for just one hour, as a sign of their commitment to reduce global warming, with the movement now celebrated in over 172 countries and over 7000 cities and towns worldwide.

The Sydney skyline during Earth Hour from Milson's Point, Australia.

This combination of pictures created, Saturday, shows the city skyline of Shanghai before and after the lights were switched off during the Earth Hour campaign.

Australia's iconic Sydney Opera House before and after Earth Hour in this combo of pictures.

The Marina Bay Sands hotel and resort in Singapore is shown in this before and after Earth Hour combination of images.

An aerial view of Shanghai's skyline on Earth Hour day is seen, Saturday, in these combination images.

Tourists kiss in front of Malaysia's landmark Petronas Twin Towers with lights on before marking Earth Hour 2016 in Kuala Lumpur, Malaysia.