Event venues including Earls Court, the Royal Albert Hall, the Natural History Museum and Olympia joined historic landmarks the Eiffel Tower and the Empire State in the one-hour power saving initiative.
The event kicked-off at 8.30pm in Chatham, a South Pacific island with only 12 street lamps. Some 25 hours later, but at 9.30pm the same day, it finished in the Galapagos Islands, where scientists shared a candle-lit dinner with several hundred residents and environmental activists.
Last year WWF's event convinced hundreds of millions of people in 88 countries to take part. This year, organisers said the figure is close to a billion.
For international photos of Earth Hour click here. All Images courtesy of WWF.
"The response from citizens, businesses and government has been truly phenomenal. Crossing geographic, economic and cultural boundaries, it has brought together people from all over the planet to celebrate the one thing we all share – the place we live," said Earth Hour co-founder and executive director Andy Ridley.
"WWF’s Earth Hour, at a personal, local and global level has become a rallying point for those who want action on climate change and are prepared to be part of the solution," he added.
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