A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach on November 27, 2012, which closed some beaches for swimming including Bondi Beach for a period of time. While the red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation. (Photo by William West/AFP Photo)

Sydney artist Phillip George poses with two surfboards of his own design at Marks Park, Tamarama on December 16, 2008 in Sydney, Australia. (Photo by Don Arnold/Getty Images)

Australian jouster Kimberly Belcher poses for a portrait in her armour on the sidelines of the jousting tournament at the St Ives Medieval Fair in Sydney, one of the largest of its kind in Australia, September 22, 2016. (Photo by Jason Reed/Reuters)

A performer dressed in costume prepares to participate in the Gay and Lesbian Mardi Gras parade in Sydney, Australia, March 5, 2016. The Sydney Mardi Gras parade began in 1978 as a march and commemoration of the 1969 Stonewall Riots of New York. It is an annual event promoting awareness of gay, lesbian, bisexual and transgender issues and themes. (Photo by David Gray/Reuters)

British artist, Mark Coreth sits on top of the “Sydney Ice Bear” carved from a 10 tonne block of ice to illustrate how humans affect climate change in the Arctic at Customs House on June 3, 2011 in Sydney, Australia. The public will be welcomed to touch the bear, and leave an imprint which will begin the melting process and act as a metaphor for how humans affect the environment. The ice bear's has visited six cities on it's global tour since 2009; the visit to Sydney coincides with World Environment Day on June 5. (Photo by Lisa Maree Williams/Getty Images)

In this handout image provided by Sydney Tower Eye, a visitor scans the skyline and harbour of Sydney from a viewing platform at the Sydney Tower Eye, on December 16, 2011 in Sydney, Australia. Sydney is suffering from its coldest start to summer since 1960. (Photo by Eugene Tan/Hausmann Communications via Getty Images)

A woman waters the plants outside her house in an alley at a slum in Mumbai October 28, 2014. (Photo by Danish Siddiqui/Reuters)