Landmarks across the world went dark on Saturday to mark this year's Earth Hour.
Buildings including Big Ben, the Eiffel Tower, the Sydney Opera House and the Colosseum in Rome switched off their lights for the global event.
In the UAE, Dubai's Museum of the Future and the Burj Khalifa also joined in the day of environmental action.
Earth Hour, spearheaded by the World Wide Fund for Nature (WWF), urges supporters to symbolically switch off and 'give an hour for Earth’, spending 60 minutes doing something positive for our planet
These activities include turning off their lights for one hour, signing a petition, sharing energy saving tips or supporting wildlife.
WWF said that last year saw the biggest Earth Hour since its launch in 2007, with more than 410,000 hours given to the planet by supporters in 190 countries and territories
António Guterres, the Secretary General of the UN, on Friday asked for people around the world to participate.
Sydney Opera House goes dark for Earth Hour
“On Earth Hour, millions of people around the world switch off the lights to shine a light on the plight of our planet,” he said in a video message.
“This year, I invite you to be one of them. The need is urgent,” Mr Guterres stressed.
He pointed out that global climate is collapsing, as last year was the hottest ever.
