Landmarks in cities across the Middle East, Europe and Africa followed those in Asia in being plunged into darkness on Saturday evening to mark Earth Hour, an event designed to raise awareness on climate change organized by the conservation group, the World Wildlife Fund.
Lighting on palaces, mosques, churches and symbols of civic pride from Beijing to Moscow and Baku to South Africa were doused at 8:30pm local time.
Organizers expect hundreds of millions of people across more than 150 countries to turn off their lights for 60 minutes on Saturday night at 8:30 pm local time in a symbolic show of support for the planet.
Major western landmarks taking part will include The Acropolis, Tower of Pisa, The Spanish Steps, Brandenburg Gate, Buckingham Palace, Tower Bridge, The UK Houses of Parliament, Big Ben, Las Vegas Strip, Times Square, The Empire State Building and Niagara Falls.
Earth Hour has seen a yearly increase in the number of participants since it began in Sydney in 2007, but has also attracted growing attention from critics, who dismiss it as tokenism that has not led to meaningful change.
The WWF acknowledges the symbolic nature of the event, but argues it creates political space and demand for large scale change.