Fishermen catch fish at Mao'er lake at the start of winter fishing season which is a local custom to welcome the new year on December 29, 2018 in Huaian, Jiangsu Province of China. (Photo by VCG/VCG via Getty Images)

A boy covers his head with fallen leaves as he enjoys a stroll with his family in a park in downtown Frankfurt, Germany, November 6, 2016. (Photo by Kai Pfaffenbach/Reuters)

Polar bears prepare to feast on the remains of a bowhead whale, harvested legally by whalers during their annual subsistence hunt, just outside the Inupiat village of Kaktovik, Alaska, USA, 10 September 2017. As climate change shrinks their natural habitat, polar bears are turning Kaktovik into their very own sanctuary city. (Photo by Jim Lo Scalzo/EPA/EFE)

Marani Devi Chaudhary (C), aged 40, performs a ritual in front of shaman Paltan Yadav (unseen) at her home in Rajaur village in Dhanusha district, Nepal, 02 November 2017. The shaman identified Marani Devi to be possessed by their lineage god who was dissatisfied by their worship is thought by the family to have caused them misfortune and is even feared lead to their death. (Photo by Narendra Shrestha/EPA/EFE)

A camel is seen as he is being brought for the foot surgery at the Dubai Camel Hospital in Dubai, UAE, December 11, 2017. (Photo by Satish Kumar/Reuters)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

A dog is seen at the entrance of a house in the flooded residential area of Villeneuve-Saint-Georges, near Paris, France January 26, 2018. The Paris region has been deeply affected by the floods that hit the country over the past week, but in Paris, it was business as usual. (Photo by Christian Hartmann/Reuters)

A woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)