The Sydney Skyline is seen before the lights are switched off for Earth Hour on March 26, 2011 in Sydney, Australia. Earth Hour encourages individuals around the world to turn off their lights for one hour at 20:30 local time on March 26, 2011 to take a stand against climate change. The largest Earth Hour was in 2010 when 128 countries participated.

A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

A handout image released by the Taronga Zoo shows Veiled Chameleon hatchlings at Taronga Zoo in Sydney, Australia, 11 March 2015. Taronga has welcomed more than 20 baby chameleons, with the last of three clutches of eggs hatching this week. Veiled Chameleons, or Chamaeleo calyptratus, are native to Saudi Arabia and Yemen and can live up to five years. (Photo by EPA/Taronga Zoo)

Two keepers at the Australian Reptile Park in New South Wales struggle with Leonardo, an alligator snapping turtle weighing 45 kilos at the park in Gosford, NSW 2 July 2015. The 50cm long Leonardo – who was smuggled illegally into Australia and found in a Sydney sewer in November 2000 – was removed from his tank for an annual health check. And as a gesture to onlooking press photographers demonstrated his strength by snapping a piece of bamboo in half. (Photo by EPA/HO)

In this photo provided by the RSPCA/Australian Capital Territory, an overgrown sheep found in Australian scrubland is prepared to be shorn in Canberra, Australia, Thursday, September 3, 2015. The wild, castrated merino ram named Chris, yielded 40 kilograms (89 pounds) of wool – the equivalent of 30 sweaters – and sheded almost half his body weight. (Photo by RSPCA ACTvia AP Photo)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

Residents look on as flames burn through bush on January 04, 2020 in Lake Tabourie, Australia. A state of emergency has been declared across NSW with dangerous fire conditions forecast for Saturday, as more than 140 bushfires continue to burn. There have been eight confirmed deaths in NSW since Monday 30 December. 1365 homes have been lost, while 3.6 million hectares have been burnt this fire season. (Photo by Brett Hemmings/Getty Images)

A Tufted Capuchin sits in a hanging food tray on a tree in it's enclosure at Sydney Zoo on February 24, 2020 in Sydney, Australia. Sydney Zoo, located at Bungarribee Park in Western Sydney, is the first new zoo to be built in Sydney in more than 100 years. The Zoo opened to the public on 7 December 2019. (Photo by Mark Kolbe/Getty Images)