Opera House glows green for Earth Hour - Sydney Morning Herald

Glowing green: The Sydney Opera House. Photo: AFP

The Sydney Opera House has glowed green while much of Australia plunged into darkness as the country united for the Earth Hour campaign on climate change.

Thousands of households and businesses across Australia switched off their lights at 8.30pm in an hour-long show of symbolic support for the planet.

And in a break from the usual Earth Hour protocol, selected venues - including the Opera house and the Arts Centre Melbourne - glowed a dark green to represent the campaign's push for people to embrace renewable energy.

The Australian event will trigger a global switch off, with hundreds of millions of people in more than 150 countries set to turn their lights off.

Organisers say Earth Hour, now in its seventh year, has captured the imagination of environmentalists everywhere.

"What started as an event in Sydney in 2007 with 2 million people has now become a tradition across the country and across the world," Dermot O'Gorman, head of the World Wildlife Fund-Australia, said.

"It's now an organic, people-powered movement ... which is fantastic."

In addition to dimming the lights, Australian Earth Hour celebrations included various community events, such as street festivals in Sydney's Newtown, large concerts in Perth and bushwalks in Canberra.

With restaurant diners eating by candlelight, outback communities going dark and iconic buildings standing in shadows, Mr O'Gorman believes Earth Hour has played a part in drawing attention to energy use.

"We've always heard anecdotally that it has made people change their actions and look at their impact on the planet in a more considered way," he said.

"Earth Hour has always been about empowering people to realise that everybody has the power to change the world in which they live, and thousands of people switching to renewable energy is a perfect example."

Sydney's lights out example will be followed by countries and territories across the globe.

Newcomers to the event this year include Palestine, Tunisia, Suriname and Rwanda and Russia, while famous landmarks such as the Eiffel Tower, Buckingham Palace and the Empire State Building will again take part.

AAP