From Sydney, Australia... ...To Beijing's Olympic Bird's Nest and Water Cube.... ...To Kuala Lumpur's giant Twin Towers. Landmarks around the globe switched off their dazzling lights to mark Earth Hour. 　　The annual event organised by the World Wildlife Fund is intended to focus attention on the need for action on climate change. And the Fund says this year the number of nations taking part has smashed previous records. 　　William Yu, WWF-Hong Kong's Head of Climate Programme: "We have 150 countries, together with 6, 400 cities, participating in Earth Hour." The big turn-off spread across Europe during the course of Saturday (March 31). 　　France hit the off-switch on the Eiffel Tower for five minutes. In Athens the Parthenon was plunged into darkness. On to the Middle East where the world's tallest tower, Dubai's Burj Khalifa followed suit. 　　As the event moved on to the United States and onwards the Empire State building did its bit. 　　Lucian Caria: "Too much light in New York, someone had to do something." Natalie Grandison: "I think it's a good symbolic reference for sure." 　　Heidi Blair: "I don't think it's a good cause, no. I have my own opinions of global warming." 　　Earth Hour started in 2007. Since that time it's grown from a one-city initiative to a global movement across all seven continents.(Paul Chapman/ Reuters)