Six million Aussies set to switch off for Earth Hour tonight

The World Wildlife Fund is encouraging people to switch off their lights for an hour to highlight the need for action of climate change.

More than six million Australians are expected to switch off their lights for the annual Earth Hour conservation movement.

Earth Hour is 8.30pm-9.30pm Saturday, March 24 AEST.

The World Wildlife Fund initiative encourages people to go without power for one hour on Saturday night to highlight the need for action on climate change.

WWF is also using this year's event, starting at 8.30pm, to draw attention to declining biodiversity.

Half of Australia's bird and reptile species, two-thirds of mammals, nearly 80 per cent of amphibians and 60 per cent of plants are at risk of disappearing by the next generation unless carbon emissions are drastically lowered, the organisation says.