Lights go out around the world for 10th Earth Hour

The initiative began in Australia in 2007 as a grass roots gesture by the World Wildlife Fund (WWF) Australia against man-made carbon dioxide emissions linked to a warming planet.

Glasses with lights lamps form the number 60, representing the 60 minutes of Earth Hour, during Earth Hour in Makati city, metro Manila, Philippines March 25, 2017. Photo by Reuters/Romeo Ranoco

Hundreds of people form a 60+ sign using solar powered lights at 8:30 p.m. as Hanoi Opera House's lights go off in Hanoi on Mrch 25, 2017. Photo by VnExpress/Giang Huy

In 2017, it involved the switching off of electric lights for an hour in 7,000 cities across 172 countries, at 8:30 p.m. local time, with the aim of highlighting the need to act on climate change, and saving a few megawatts of power in the process.

The Sydney Harbour Bridge before and during the tenth anniversary of Earth Hour in Sydney, Australia, March 25, 2017. Photo by Reuters/David Gray

Among the famous buildings and structures taking part in Australia are Sydney's Opera House, the Harbour Bridge, Luna Park, Town Hall, and Sydney Tower Eye.

Internationally the list includes some of the world's best known sky-scrapers and historic buildings including the world's tallest building, the Burj Khalifa in Dubai, London's Big Ben and Houses of Parliament, the Colosseum in Rome, Istanbul's Blue Mosque, the Eiffel Tower, Moscow's Kremlin and Red Square and the Pyramids of Egypt.

The Eiffel Tower before (L) and during Earth Hour in Paris, France, March 25, 2017 at which lights are switched off around the world at 8:30 p.m. on Saturday evening to mark the 10th annual Earth Hour and to draw attention to climate change. Photo by Reuters/Philippe Wojazer

Tokyo Tower before (L) and after its lights were switched off for Earth Hour in Tokyo, Japan March 25, 2017. Photo by Reuters/Issei Kato

Laser light beams as buildings are lighted up and a tourist junk sailing past before (top) and during (bottom) Earth Hour, at the financial Central district in Hong Kong, China March 25, 2017. Photo by Reuters/Bobby Yip

The hill of the Acropolis is pictured during Earth Hour in Athens, Greece, March 25, 2017. Photo by Reuters/Michalis Karagiannis

While the organizers of Earth Hour said they do not audit results of the energy saving initiative, the group has commissioned research indicating up to one in four Australians gets involved.

WWF says Earth Hour can take credit for various environmental initiatives, like the 2013 declaration of a 3.4 million hectare marine park in the waters off Argentina, the planting of a forest in Uganda and a ban on soft plastics in the Galapagos Island.