Towns and cities around the world are turning out the lights for an hour, to highlight the threat of climate change.
Towns and cities around the world are turning out the lights for an hour, to highlight the threat of climate change.
"Earth Hour" begins in Sydney, Australia, at 2000 (0900 GMT), when lights on landmarks such as the Opera House and Harbour Bridge will go out.
"Earth Hour" began in Sydney at 2000 local time (0900 GMT), when lights went out on landmarks like the Opera House and Harbour Bridge.
Cities around the world - among them Bangkok, London and Chicago - will follow suit when clocks reach 2000 local time on Saturday.
Bangkok, London and Chicago are among cities due to follow suit when clocks reach 2000 local time.
The initiative began in Sydney last year, but now involves 35 countries.
The initiative began in Sydney last year but now involves 35 countries.
"Earth Hour is about everyone and every organisation, from individuals to global companies, joining together to own a shared problem - climate change," organiser Andy Ridley told AP news agency.
"Earth Hour is about everyone and every organisation, from individuals to global companies, joining together to own a shared problem - climate change," organiser Andy Ridley told AP news agency.
Similar campaigns have been held before, but not on this scaleHe said he had not expected the event to grow in scale so quickly.
He said he had not expected the event to grow in scale so quickly.
"What's amazing is that it's transcending political boundaries and happening in places like China, Vietnam, Papua New Guinea. It really seems to have resonated with anybody and everybody."
"What's amazing is that it's transcending political boundaries and happening in places like China, Vietnam, Papua New Guinea. It really seems to have resonated with anybody and everybody."
More than two million residents in Sydney reportedly participated in last year's event - cutting energy usage by more than 10% for the hour.
More than two million residents in Sydney reportedly participated in last year's event - cutting energy usage by more than 10% for the hour.
Observers say droughts and water shortages have drawn Australians' attention to the problem of global warming.
Observers say droughts and water shortages have drawn Australians' attention to the problem of global warming.
Per capita the vast continent is the world's largest producer of carbon dioxide and other gases that most scientists believe are helping to warm the Earth's atmosphere.
Per capita the vast continent is the world's largest producer of carbon dioxide and other gases that most scientists believe are helping to warm the Earth's atmosphere.
New Prime Minister Kevin Rudd has made the environment one of his priorities, signing up to the Kyoto Protocol on tackling climate change soon after he took office.
New Prime Minister Kevin Rudd has made the environment one of his priorities, signing up to the Kyoto Protocol on tackling climate change soon after he took office.
The Google web search engine is marking the event by putting a dark background on its homepage.
The Google web search engine is marking the event by putting a dark background on its homepage.
Will you be switching your lights off? What do you think of this idea? Send us your comments using the form below:
Will you be switching your lights off? What do you think of this idea? Send us your comments using the form below:
