This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)

An Afghan woman clad in burqa begs in a snow-covered street in Kabul, Afghanistan on January 7, 2020. (Photo by Mohammad Ismail/Reuters)

A resident digs out his walkway in St. John's Newfoundland on Saturday, January 18, 2020. The state of emergency ordered by the City of St. John's is still in place, leaving businesses closed and vehicles off the roads in the aftermath of the major winter storm that hit the Newfoundland and Labrador capital. (Photo by Andrew Vaughan/The Canadian Press via AP Photo)

Swedish climate change activist Greta Thunberg, Isabelle Axelsson and German Luisa Neubauer take part in a climate strike protest during the 50th World Economic Forum (WEF) annual meeting in Davos, Switzerland on January 24, 2020. (Photo by Denis Balibouse/Reuters)

Wu Lingling, a nurse from Central Hospital of Shanghai Fengxian District says goodbye to her husband Zhao Kun before leaving for Wuhan at Shanghai South Railway Station in east China's Shanghai, January 27, 2020. A team comprised of 50 medical workers from 40 hospitals in Shanghai left for Wuhan City on Monday to aid the novel coronavirus control efforts there. (Photo by Ding Ting/Xinhua News AgencyAlamy Live News)

A burning tree is seen during a fire in an area of the Amazon rainforest in Itapua do Oeste, Rondonia State, Brazil, September 11, 2019. (Photo by Bruno Kelly/Reuters)

Costumed revelers pose in front of the Chapell bridge on the opening day of the carnival in Lucerne, Switzerland, 20 February 20​20. The carnival takes place in Lucerne from 20 to 25 February 2020. (Photo by Alexandra Wey/EPA/EFE)

A resident pulls back a rope with groceries tied to the end of it, delivered by community workers, at a residential compound under sealed management in Yichang, Hubei province, China on February 22, 2020. (Photo by Reuters/China Daily)