An airplane is silhouetted at sunrise, seen from the suburb of Saint-Cloud, near Paris, France, 08 December 2016. Paris is undergoing a third day pollution spike, prompting the city to limit vehicle circulation. (Photo by Ian Langsdon/EPA)

A Sotheby's employee poses with a claw-set diamond ring weighing 36.57 carats during a press preview of an upcoming auction from Sotheby's in Geneva, Switzerland, 08 May 2019. The ring is expected to reach between 4,500,000 to 5,500,000 US Dollars during the “Magnificent Jewels and Noble Jewels” auction on May 14 in Geneva. (Photo by Valentin Flauraud/EPA/EFE)

A tourist jumps inside an upside-down house at Fengjing Ancient Town, Jinshan District, south of Shanghai, May 1, 2014. The upside-down house was built as a tourist attraction using everyday household items and furniture. (Photo by Aly Song/Reuters)

Hucul horses play in the wild meadows and forests near Odrzychowa in southeastern Poland on October 18, 2014. Huculs, a primitive breed of horse, escaped total extinction due to the efforts of scientists and Polish farmers. (Photo by Janek Skarzynski/AFP Photo)

Burdened with a shawl full of her belongings, a woman stops for a rest on the road between Julaca and Puno in Peru. (Photo by Three Lions/Getty Images). Circa 1955

In this Saturday, March 21, 2015 photo, a porter rests carrying supplies for the upcoming climbing season, near the Everest Base camp, Nepal. Nepal has cleared more than 300 mountaineers to climb Mount Everest after they had to abandon last year's efforts when an ice avalanche killed 16 guides in the mountain's deadliest disaster, an official said on March 20. The three-month climbing season for Everest, the world's tallest mountain, begins in March. (Photo by Tashi Sherpa/AP Photo)

A production department of a textile factory is seen abandoned in Kaduna, Nigeria November 3, 2016. President Muhammadu Buhari hopes to revive the once flourishing textile and leather industries in northern Nigeria to end the country's dependence on oil exports and diversify Africa's biggest economy. (Photo by Afolabi Sotunde/Reuters)

Dressed up as Punxsutawney Phil, Marty Nagy, of Hallandale Beach, Fla., gives thumbs up to passers by before the start of the 12th annual Groundhog Day on Hollywood Beach, Tuesday, February 2, 2016, in Hollywood, Fla. The event, which featured breakfast and an ocean plunge, benefited the Hollywood Beach Lifeguard Competition Team. (Photo by Wilfredo Lee/AP Photo)