Lights to go off for Earth Hour
Homes, office blocks and Australian landmarks will go dark as millions of Australians take part in Earth Hour - a mass symbolic gesture urging action on the environment.
More than 150 cities and towns have signed up to the worldwide event, which originated in Sydney in 2007, which kicks off at 8.30pm (local times) on Saturday across Australia.
Conservation organisation WWF-Australia says Sydney Opera House and the Harbour Bridge will be the first to go dark followed by buildings and venues around the harbour.
Even the Opera Australia production of La Traviata, being held on a purpose-built stage over the water at Circular Quay, will fade to black as opera fans join in on the hour-long action.
This year, remote areas such as the Torres Strait Islands, Christmas Island, and the Cocos (Keeling) Islands will also take part in Earth Hours.
WWF-Australia chief executive Dermot O'Gorman highlighted Earth Hour's importance as the planet was facing "unprecedented environmental challenges".
"One person can make a difference. Hundreds of millions of people uniting to show their support for the environment and making a commitment to action in their daily lives, can achieve real change," Mr O'Gorman said in a statement on Friday.
WWF Australia says more than 140 different community events will also be held in cities and towns during Earth Hour aimed at committing to a more sustainable future.
A record total of 147 countries will participate in this year's Earth Hour.