Climate change activist Greta Thunberg reacts during a news conference during COP25 climate summit in Madrid, Spain, December 9, 2019. (Photo by Juan Medina/Reuters)

Two zebras stand so close in Ngorongoro Crater, Tanzania. (Photo by Zhayynn James/Solent News)

In this November 12, 2015, file photo, Mt. Everest is seen from the way to Kalapatthar in Nepal. An American climber has died near the summit of Mount Everest and an Indian climber is missing after heading down from the mountain following a successful ascent, expedition organizers said Sunday. (Photo by Tashi Sherpa/AP Photo)

Women are reflected in a puddle as they walk across Red Square in Moscow, Russia on April 26, 2018. (Photo by Yuri Kadobnov/AFP Photo)

A man looks at a car hit by a post after a tornado ripped through a neighbourhood in Havana, Cuba on January 28, 2019. (Photo by Fernando Medina/Reuters)

A child wearing a costume runs up the steps during Purim celebrations at the Coral Temple synagogue in Bucharest, Romania, Wednesday, March 20, 2019. Children put on fancy costume dress joining dozens of believers from Romania's Jewish community who attended a Purim service to celebrate the Jews' salvation from genocide in ancient Persia, as recounted in the Book of Esther. (Photo by Vadim Ghirda/AP Photo)

Soyuz MS-12 spacecraft with crew members of Expedition 59/60 Russian cosmonaut Alexey Ovchinin, NASA astronauts Christina Koch and Nick Hague lifts off from the launch pad at the Russian leased Baikonur cosmodrome, Kazakhstan, 15 March 2019. Hague, Koch, and Ovchinin will spend six-and-a-half months living and working aboard the International Space Station. (Photo by Sergei Ilnitsky/EPA/EFE)

A man walks by as tourists take selfies on the French Riviera city of Nice on June 24, 2019, as temperatures soar to 33 degrees Celsius. Forecasters say Europeans will feel sizzling heat this week with temperatures soaring as high as 40 degrees Celsius (104 degrees Fahrenheit) in an “unprecedented” June heatwave hitting much of Western Europe. (Photo by Valery Hache/AFP Photo)