170 nations and territories take part in bid to highlight global warming.

Sydney’s Opera House and Harbour Bridge plunged into darkness on Saturday to mark the Earth Hour, as global landmarks began dimming their lights to draw attention to climate change.

Millions of people from some 170 countries and territories were expected to take part in the annual bid to highlight global warming caused by the burning of coal, oil and gas to drive cars and power plants.

The event, which originated in Sydney, has grown to become a worldwide environmental campaign, celebrated across all continents.

Conservation group WWF, which organises Earth Hour, said great strides had been made in highlighting the dire state of the planet.

Powerful movement

“We started Earth Hour in 2007 to show leaders that climate change was an issue people cared about,” coordinator Siddarth Das said.

“For that symbolic moment to turn into the global movement it is today, is really humbling and speaks volumes about the powerful role of people in issues that affect their lives.”

In Sydney, many harbourside buildings switched off their lights for an hour from 8.30 p.m. local time as the call for action began rolling out across the world.

“I agree with the concept, 100%,” said student Ed Gellert, 24, in Sydney.

“I think people probably avoid the fact that climate change is happening, so it’s good to see the city grouping together to support Earth Hour,” he said. From Australia, it moved westward through Asia, where Hong Kong’s skyline went dark in solidarity while at Myanmar’s most sacred pagoda, the Shwedagon, 10,000 oil lamps were lit to shine a light on climate action. The event was also marked throughout Africa, Europe and the Americas.

Monuments including the Empire State Building, the Kremlin, Big Ben, the Leaning Tower of Pisa, the Eiffel Tower and Egypt’s pyramids were all scheduled to switch off. A concert by candlelight in Lisbon, a “carbon-neutral run” in Singapore, and a tree-planting ceremony in Tanzania were among the events planned.

The WWF said teams around the world would use Earth Hour this year to highlight climate issues most relevant to individual countries. In South Africa, the focus would be on renewable energy while in China, the WWF was working with businesses to encourage a shift towards more sustainable lifestyles. Last year, scientists recorded the Earth’s hottest temperatures in modern times for the third year in a row. Nations agreed in Paris in 2015 to limit average global warming to two degrees Celsius over pre-industrial temperatures.