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)

British Prime Minister Boris Johnson visits the Pavegen stand, a company that converts footsteps into energy, at the Innovation Zone during the UK-Africa Investment Summit in London, Britain on January 20, 2020. (Photo by Leon Neal/Pool via Reuters)

People take photos of hotel room lights shaping the word “Zero”, referring to Covid-19 cases, in Taipei, Taiwan, 17 April 2020. According to news reports Taiwan records no new COVID-19 cases for third time this week. Medical experts are rushing to develop a vaccine for the COVID-19 disease caused by the SARS-CoV-2 coronavirus and advising people to practice social distancing and proper hygiene. (Photo by David Chang/EPA/EFE/Rex Features/Shutterstock)

A pedestrian wearing a form of PPE (personal protective equipment) of a perspex full-face covering, as a precautionary measure against COVID-19, walks across Oxford Street in central London on June 11, 2020, as non-essential shops prepare to re-open on June 15. Britain's current guidelines on social distancing remain at two metres (2M), but business leaders and some politicians are on Thursday calling for it to be reduced to one (1M), or one-and-a-half (1.5M) metres. (Photo by Justin Tallis/AFP Photo)

The Sea Life Trust team move Beluga Whale Little Gray from a tugboat during transfer to the bayside care pool where they will be acclimatised to the natural environment of their new home at the open water sanctuary in Klettsvik Bay in Iceland on August 7, 2020. The two Beluga whales, named Little Grey and Little White, are being moved to the world's first open-water whale sanctuary after travelling from an aquarium in China 6,000 miles away in June 2019. (Photo by Aaron Chown/PA Images via Getty Images)

A woman wears a mask while carrying a dog in the street on January 22, 2020 in Wuhan, Hubei province, China. A new infectious coronavirus known as “2019-nCoV” was discovered in Wuhan as the number of cases rose to over 400 in mainland China. Health officials stepped up efforts to contain the spread of the pneumonia-like disease which medicals experts confirmed can be passed from human to human. The death toll has reached 17 people as the Wuhan government issued regulations today that residents must wear masks in public places. Cases have been reported in other countries including the United States, Thailand, Japan, Taiwan, and South Korea. (Photo by Getty Images/China Stringer Network)

A military helicopter flies over people during the Afghan Security Forces Exhibition, at the Darul Aman Palace in Kabul, Afghanistan, Wednesday, March 3, 2021. The three-day military exhibition in Kabul allowed civilians to have a first hand view and take pictures of weaponry used by Afghan Security forces. (Photo by Rahmat Gul/AP Photo)

Staff members work on sorting and assembling the skeleton of a fossilized Triceratops dinosaur, in Paris, France, 31 August 2021. The skeleton of a Triceratops, an over 66 million years old dinosaur, knicknamed “Big John”, will be auctioned at the Drouot Auction House on 21 October 2021 and is estimated to fetch a total of 1.5 million euros. (Photo by Christophe Petit Tesson/EPA/EFE)