PARIS (AFP) - Lights went off in thousands of cities and towns across the world on Saturday for the annual Earth Hour campaign, which is aiming to raise money via the Internet for local environmental projects.
Iconic monuments from Athens' Acropolis, the Kremlin in Moscow and London's Houses of Parliament, to Sydney's Opera House and India Gate in New Delhi, went dark for 60 minutes from 8:30pm local time.
The world's tallest building, Dubai's 200-storey Burj Khalifa, joined the action expected to include some 7,000 cities and towns in 150 countries from New Zealand to New York - where the Empire State Building will switch off - by the time the event covers all the planet's time zones.
At the Vatican, before St Peter's Basilica plunged into darkness, dozens of people shouted out a countdown, including a group of children dressed as Spider-Man - the first ever superhero ambassador for the campaign.
The Singapore-based initiative of conservation group WWF was boosted by Hollywood star power, with The Amazing Spider-Man 2 stars Andrew Garfield, Emma Stone and Jamie Foxx leading ceremonies at the city-state's Marina Bay district.
In Paris, a nine-year-old "mini Spider-Man" did the honours at the Eiffel Tower. However, since the tower that symbolises the City of Light was still open to visitors, its spectacular dancing lights were idled for only five minutes for security reasons.
In Cape Town, South Africa - WWF's 2014 Earth Hour capital - floodlights powered by energy from a nearby windfarm were trained on Table Mountain in order to be switched off for the observance.
Hong Kong's stunning waterfront skyline was unrecognisable during the event, with the city's tallest skyscraper, the International Commerce Centre, stripped of the vast light show usually wrapped around its 118 storeys.
Earth Hour, which was launched in Sydney in 2007, partnered with payments giant PayPal to allow donors to contribute to specific projects from Russia and India to Canada and Indonesia, using Asian fund-raising site Crowdonomic.
Earth Hour chief executive Andy Ridley said before the lights went off in Singapore that the event had moved beyond symbolism to concrete action.
"If you want to get real social change you need to have symbolism," he told Agence France-Presse.
"We are seeing some really big outcomes."
1.3 BILLION WITHOUT POWER
But it has drawn criticism, including from Danish political scientist Bjorn Lomborg who argues it does little for the real problem of global warming and diverts resources from other problems.
"This celebration of darkness sends the wrong message," Mr Lomborg said in a statement this week.
"While more than a billion people across the globe make a symbol of forgoing non-essential electrical power for one hour a year, another 1.3 billion people across the developing world will continue to live without electricity as they do every other night of the year."
Projects under the "Earth Hour Blue" crowdfunding scheme - which aim to raise more than US$650,000 (S$820,000) in total - include a turtle centre in Italy and funding for forest rangers in Indonesia.
Other projects include a US$24,000 effort in the Philippines to bring fibreglass boat technology to coastal communities affected by Super Typhoon Haiyan in November last year.
In Nepal, US$100,000 is being sought for a programme called "A Flame Called Hope" to provide access to biogas energy for 150 households in the Terai region, reducing the need for wood as fuel and helping protect the habitat of endangered wildlife, according to the Earth Hour website.
Spider-Man 2 star Garfield told journalists that he was a personal supporter of the Nepal project.
"What they are doing is turning waste into energy, it's like the cycle of life right there, if only everyone knew how simple it was," he said.