Two visitors look at an artwork “Home Sweet Home: Pandemic Love 1” created by Hong Kong artist Mak Ying Tung at Art Basel in Hong Kong Wednesday, May 19, 2021. Art Basel, one of the world's most prestigious modern and contemporary art exhibitions, is returning to Hong Kong in its ninth edition. The prestige art fair is hosting 104 galleries from 23 countries and territories. (Photo by Vincent Yu/AP Photo)

Pigeon fancier Yonisbel Santana poses for a photo at his rooftop in Havana, Cuba, May 18, 2021. Havana's pigeon keepers crane out of a window, intently watching the grey birds take flight. Mostly staying indoors due to the country's worst outbreak of COVID-19 since the coronavirus pandemic began in March last year, Cubans are increasingly breeding pigeons as a form of escape. (Photo by Alexandre Meneghini/Reuters)

Young women wearing facemasks and traditional costumes of Song dynasty and Tang dynasty are seated on a bench in a park next to the East Lake in Wuhan, in China’s central Hubei province on May 17, 2020. The Guardian picture desk has chosen on December 17, 2020, the AFP photojournalist Hector Retamal as “Agency Photographer of the Year 2020” for his coverage of the novel coronavirus Covid-19 pandemic in Wuhan, China. (Photo by Hector Retamal/AFP Photo)

Police detain a woman during a protest against Prime Minister Benjamin Netanyahu and his government's handling of the coronavirus disease (COVID-19) crisis, near Netanyahu's residence in Jerusalem on July 24, 2020. Reimposed coronavirus curbs after a rise in new COVID-19 cases have prompted Israelis demanding better state aid to take to the streets in almost daily demonstrations. Public anger has also been fueled by corruption alleged against Netanyahu, who went on trial in May for bribery, fraud and breach of trust – charges he denies. (Photo by Ammar Awad/Reuters)

A child of a migrant worker drinks water as his mother holds him while waiting in a queue for transport to reach to a railway station to board a train to their home state of northern Uttar Pradesh, after a limited reopening of India's giant rail network following a nearly seven-week lockdown to slow the spreading of the coronavirus disease (COVID-19), in Ahmedabad, India, May 15, 2020. (Photo by Amit Dave/Reuters)

Iranian athlete Maryam Toosi practises on the rooftop of her apartment building following the closure of sports facilities as part of measures aimed at containing the COVID-19 coronavirus, in Iran's capital Tehran on May 19, 2020. The coronavirus pandemic has forced the world's athletes to keep fit in confinement. The novel coronavirus has claimed the lives of nearly 7,200 people in Iran, making it the deadliest outbreak in the Middle East. The government ordered the closure of sports facilities in mid-March as part of measures aimed at containing the virus. (Photo by Atta Kenare/AFP Photo)

A boy sits on the back of a crocodile on May 19, 2018 at a pond in Bazoule in Burkina Faso, a village which happily shares its local pond with “sacred” crocodiles. Crocodiles may be one of the deadliest hunters in the animal kingdom, but in a small village in Burkina Faso it is not unusual to see someone sitting atop one of the fearsome reptiles. According to local legend, the startling relationship with the predators dates back to at least the 15 th century. The village was in the grip of an agonising drought until the crocodiles led women to a hidden pond where the population could slake their thirst. (Photo by Olympia de Maismont/AFP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)