A boy sits in a canoe in front of a shed built on a raft in the Makoko fishing community on the Lagos Lagoon, Nigeria February 29, 2016. In Makoko, a sprawling slum of Nigeria's megacity Lagos, a floating school capable of holding up to a hundred pupils has since November brought free education to the waterways known as the Venice of Lagos. It offers the chance of social mobility for youngsters who, like most of the city's 21 million inhabitants, lack a reliable electricity and water supply and whose water-based way of life is threatened by climate change as well as rapid urbanisation. (Photo by Akintunde Akinleye/Reuters)

Photo taken on November 5, 2015 shows flood in Bento Rodrigues, a town in the southeastern Brazilian state of Minas Gerais, after a dam at a mining waste site burst early Thursday. An iron ore tailings dam in the southeast Brazilian state of Minas Gerais collapsed Thursday, killing at least 15 people, according to local media reports. (Photo by Agencia Estado/Xinhua Press/Corbis)

Palestinians kids from the West Bank Palestinian village Umm Al Rajaj cross the Meitar checkpoint into Israel on their way to the beach of Tel Aviv for the first time, Israel, 10 August 2016. A group of humanitarian Israeli women called in Arabic “Min Al Baher” (from the sea) voluntarily arranges authorizations and transportation for Palestinians families that live in the West Bank to cross into Israel in order to visit the sea for the first time. (Photo by Abir Sultan/EPA)

A fisherman carries his catch to sell on the beach in Libreville, Gabon, February 3, 2017. (Photo by Mike Hutchings/Reuters)

British theoretical physicist Stephen Hawking, Cambridge University Professor and Fellow, circa 1985. Stephen Hawking, the brightest star in the firmament of science, whose insights shaped modern cosmology and inspired global audiences in the millions, has died aged 76. (Photo by Gemma Levine/Getty Images)

An Afghan boy jumps off the turret of a Soviet tank on a hilltop on the the outskirts of Kabul, Sunday, March, 4, 2018. (Photo by Rahmat Gul/AP Photo)

Workers carry a metal sheet at a dockyard in Dhaka, Bangladesh, December 5, 2018. (Photo by Mohammad Ponir Hossain/Reuters)

A Pomeranian dog is seen during an international dog exhibition in Kannot, central Israel May 21, 2016. Some 850 purebred dogs from about 200 mini breeds participated in the exhibition. (Photo by Amir Cohen/Reuters)