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)

Walking figures depicting late US rock and roll legend Elvis Presley appear on a traffic light switching from green to red in Friedberg near Frankfurt, Germany, Thursday, December 6, 2018. Presley served in Friedberg from October 1958 to March 1960 as a soldier in the US Armed Forces. (Photo by Michael Probst/AP Photo)

A ranger watches a seal pup near the Northumberland coast, Farne Islands, UK on December 19, 2018, where the National Trust says the number of Atlantic grey seal pups has reached a record high thanks to an abundance of food and a lack of predators. (Photo by Owen Humphreys/PA Wire Press Association)

Chase Outlaw dodges Cochise after being bucked off in the final round of the PBR Unleash the Beast bull riding event at Madison Square Garden on January 06, 2019 in New York City. (Photo by Sarah Stier/Getty Images)

A man carries a sheep after it was rescued from mud in Sanliurfa, Turkey on January 9, 2019. Total of 67 sheep and a donkey rescued from mud by gendarmerie forces, firefighters and local people in Sanliurfa's Bozova district. (Photo by Halil Fidan/Anadolu Agency/Getty Images)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)