EARTH HOUR

Sydney embraced its second Earth Hour tonight, as hundreds of thousands of citizens turned off their lights across the city between 8 and 9pm to make a statement against climate change.

More than 370 locations around the world joined Earth Hour this year after Sydney pioneered the event in 2007.

"Earth Hour is a call to action," said Sydney's Lord Mayor Clover Moore. "People have now responded and it's time to introduce some significant long-term changes. One inspired idea that began in Sydney just 12 months ago has become a world movement," she said.

When the first Earth Hour was staged in Sydney a year ago, an estimated 2.2 million Sydneysiders took part.

Organisers are tipping a massive increase in participation as the event has gone global this year.