Earth Hour 2019 was observed on Saturday across different parts of the world in which various important government building and historical monument switched off their lights for an hour as part of a global initiative.
The Eiffel Tower, the Sydney Opera House and even the ancient Acropolis in Athens were plunged into darkness for an hour Saturday as part of a global campaign to raise awareness about climate change and its impact on the planet's vanishing plant and animal life.
WWF-Australia CEO Dermot O'Gorman told AFP that "Earth hour still is the world's largest grassroots movement for people to take action on climate change".
"It's about individuals taking personal action but joining with hundreds of millions of people around the world to show that not only do we need urgent action on climate change but we need to be protecting our planet," he added.
The event comes after some of the most dire warnings yet on the state of Earth's natural habitat and species.
WWF's own "Living Planet" report in October said 60 per cent of all animals with a backbone -- fish, birds, amphibians, reptiles and mammals -- had been wiped out by human activity since 1970.
Another study said a recent decline in bugs that fly, crawl, burrow and skitter across still water -- fuelled by deforestation, urbanisation and the rise of commercial farming -- was part of an unfolding mass extinction event, only the sixth in the last half-billion years.
Government and private institutions also kept their electric appliances switched off during the Earth Hour observed from 8.30 pm to 9.30 pm.
According to a report by ANI, the power distribution companies in the national capital saved 258 megawatt (MW) of electricity during sixty minutes of the Earth Hour.
Last year, Earth Hour was observed in more than 7,000 towns and cities in 187 countries, according to the organisers.
While the lights-off event is a symbolic gesture, Earth Hour has led successful campaigns over the past decade to ban plastics in the Galapagos Islands and plant 17 million trees in Kazakhstan.