A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

Arctic wolves in their new enclosure in the wildlife park in Hanau, Germany, 10 February 2015. The pack is one of the park's main attractions, which specializes in local and European breeds. (Photo by Boris Roessler/EPA)

Children beg for alms in a street on August 11, 2014 in Manila, Philippines. The Philippines has one of the fastest growing populations in Southeast Asia with around 100 million people. At least 12 million people live in the capital city of Manila alone, making it one of the most densely populated and largest cities in the world. Lack of space and economic opportunities has pushed around four million people to live informally along waterways, bridges and even cemeteries further straining the already weak infrastructure and straining the resources of the city. (Photo by Dondi Tawatao/Getty Images)

Tuvalu Beneath the Rising Tide by Sean Gallagher, Tuvalu. Changing environments prize: Fallen trees lie on a beach as the waves from the Funafuti lagoon in Tuvalu lap around them. Land erosion has always been a problem for the South Pacific country but problems are intensifying as sea levels rise. Rising seas are on the verge of completely submerging the tiny archipelago’s islands. (Photo by Sean Gallagher/CIWEM Environmental Photographer of the Year 2019)

A handout picture provided by Global newsroom of Czech Martin Sonka (C) leading Nigel Lamb (top) of Great Britain and Yoshihide Muroya of Japan (down) along the Mount Fuji prior the third stage of the Red Bull Air Race World Championship in Chiba, Japan on June 1, 2016. (Photo by Predrag Vockovic/EPA/Global Newsroom)

A PETA (People for the Ethical Treatment of Animals) activist with her body painted promotes veganism in Bangkok April 21, 2016. (Photo by Jorge Silva/Reuters)

Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)

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)