A waste picker unloads garbage at a waste transfer station in Bamako, Mali, August 19, 2018. In the Malian capital of Bamako, donkey carts driven by young men like 19-year-old Arouna Diabate play a vital role battling the fast-growing city's waste problem. Every morning before dawn, Diabate hitches his donkey to a cart and sets off on his rounds, going door-to-door to collect household garbage which he delivers to a local waste transfer station for a monthly salary of around $35. “I won't be picking up trash with a donkey cart for the rest of my life, but for now people appreciate us because we help clean up the homes of Bamako”, Diabate said. (Photo by Luc Gnago/Reuters)

A ballet dancer practices in the sunshine at the Southbank skatepark in London on Monday, September 17, 2018, as Storm Helene is due to bring unseasonably warm weather in London and the south east, as the low pressure draws up warm air from the south. Forecasters have downgraded warnings that Helene could pose a risk to life when it hits this week – but warned coastal communities to stay vigilant. (Photo by Kirsty O'Connor/PA Wire)

A participant races in the Brompton World Championship in Bern, Switzerland October 21, 2018. (Photo by Stefan Wermuth/Reuters)

Lindsey Vonn of USA wins the bronze medal during the FIS World Ski Championships Women's Downhill on February 10, 2019 in Are Sweden. (Photo by Leonhard Foeger/Reuters)

A young boy scavenges for re-sellable items from garbage on the streets, runs past a sign showing incumbent President Muhammadu Buhari, left, and local party official Mustapha Dankadai, right, in Kano, northern Nigeria Friday, February 15, 2019. (Photo by Ben Curtis/AP Photo)

Revellers attend the Saint Patrick's Day parade on March 17, 2019 in Dublin, Ireland. Saint Patrick, the patron saint of Ireland is celebrated around the world on St. Patrick's Day. According to legend Saint Patrick used the three-leaved shamrock to explain the Holy Trinity to Irish pagans in the 5th-century after becoming a Christian missionary. (Photo by Charles McQuillan/Getty Images)

Visitors pose for pictures under blooming cherry blossoms at a botanical garden in Nanjing, capital of China’s eastern Jiangsu province on March 15, 2019. (Photo by Reuters/China Stringer Network)

A staff member demonstrates how she puts on the helmet of a mock space suit at the C-Space Project Mars simulation base in the Gobi Desert outside Jinchang, Gansu Province, China, April 17, 2019. The facility – comprising several interconnected modules including a greenhouse and a mock decompression chamber – opened its doors to the public. (Photo by Thomas Peter/Reuters)