Tourists pose for a selfie in Cancun, October 13, 2015. Cancun's transformation in the 1970s from a small Caribbean fishing village into a strip of nightclubs and high-rise hotels has reduced biodiversity and polluted water resources as infrastructure struggles to keep up. (Photo by Edgard Garrido/Reuters)

A supporter of Venezuela's President Nicolas Maduro, with a doll depicting late Venezuela's President Hugo Chavez on his hat, reacts as he stands at the Plaza Bolivar near the building housing the National Assembly in Caracas, January 5, 2016. (Photo by Christian Veron/Reuters)

Seven year old Hungarian herding dog Derci runs along the Olympiaberg hill during stormy weather in Munich, southern Germany, Monday, January 4, 2016. (Photo by Matthias Balk/DPA via AP Photo)

Israeli soldiers play the parts of wounded civilians during a drill simulating a toxic spill from an attack on a train in Beersheba, southern Israel, 13 January 2016, as Home Front medical teams, fire fighters and police carry out rescue operations. The large scale drill is the concluding exercise of the Fourth International Conference on Healthcare System Preparedness and Response to Emergencies and Disasters and includes some 200 of the world's experts on health system readiness from around the world. The conference is dealing with all types of medical emergencies from terrorist attacks to natural disasters. (Photo by Jim Hollander/EPA)

A photograph of Cuba's former President Fidel Castro decorates a wall inside a state-run market in Havana, March 8, 2016. (Photo by Alexandre Meneghini/Reuters)

An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)

Boys play with water as they celebrate Myanmar's New Year Water Festival of Thingyan in Yangon, April 13, 2016. (Photo by Soe Zeya Tun/Reuters)

A Capybara bathes in the hot spring water at the Saitama Children's zoo in Higashi Matsuyama city, Saitama prefecture on December 21, 2014. Seven capybaras in the zoo, originally from South America, enjoyed the hot spring water on the chilly winter day in Japan. (Photo by Toshifumi Kitamura/AFP Photo)