A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)

People cheer as the ball drops at midnight in Times Square on January 1, 2015 in New York City. An estimated one million people from around the world are expected to pack Times Square to ring in 2015. (Photo by Andrew Theodorakis/Getty Images)

A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)

This image taken from video provided by TVBS shows a commercial airplane clipping an elevated roadway just before it careened into a river in Taipei, Taiwan, Wednesday, February 4, 2015. The ATR-72 prop-jet aircraft had 58 people aboard. (Photo by AP Photo/TVBS)

The Aurora Borealis seen across the sky in Lapland, Finland. The beautiful phenomenon was captured by photographer Marko Korosec on a trip to the arctic region of Lapland in Northern Finland. He used long exposures on his Canon DSLR to create the stunning images. (Photo by Marko Korosec/Barcroft Media)

A gallery staff member walks past Fleeting Monument (1985) by artist Cornelia Parker, one of the works on display at Yorkshire Sculpture Parks Longside Gallery as part of the “Making It: Sculpture in Britain 1977-1986” exhibition on March 27, 2015 in Barnsley, England. (Photo by Christopher Furlong/Getty Images)

The images of U.S. Democratic presidential candidate Hillary Clinton (L) and Republican Presidential candidate Donald Trump are seen painted on decorative pumpkins created by artist John Kettman in LaSalle, Illinois, U.S., June 8, 2016. (Photo by Jim Young/Reuters)