Lenticular cloud and zebra. (Photo by National Geographic)

A boat paddles behind a fence near a plane sitting on the flooded tarmack of the closed Don Muang airport November 3, 2011 in Bangkok,Thailand. The airport was used as a domestic terminal and was formerly the International airport. Thailand is experiencing the worst flooding in over 50 years and has affected more than nine million people. Over 400 people have died in flood-related incidents since late July according to the Department of Disaster Prevention and Mitigation. (Photo by Paula Bronstein/Getty Images)

Commuters ride on the roof of a Jakarta state rail train at Cawang train station on January 27, 2012 in Jakarta, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

Tsewang Dolma, 33, a farmer and housewife poses for a photograph in Matho, a village nestled high in the Indian Himalayas, India September 29, 2016. When asked how living in the world's fastest growing major economy had affected life, Dolma replied: “Our culture is spoiled now. We don't wear our traditional dress”. (Photo by Cathal McNaughton/Reuters)

A sеx worker participates in a march to raise public awareness on human rights issues in their profession on International Day to End Violence Against Sеx Workers in Skopje, Macedonia December 17, 2016. (Photo by Ognen Teofilovski/Reuters)

A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)

Thousands of travellers heading to their hometowns to celebrate Eid al-Fitr, the Muslim holiday to mark the end of Ramadan, wait in a traffic jam to board a ferry at the entrance to Gilimanuk port on Bali, Indonesia July 3, 2016 in this photo taken by Antara Foto. (Photo by Nyoman Budhiana/Reuters/Antara Foto)

A man sits on top of a car as he is stranded on a flooded street in Tianjin, China, July 20, 2016. (Photo by Reuters/Stringer)