A woman wearing a mask walk in a street in a Yonghegong Lama temple compound seen shrouded in smog in Beijing, China, 30 November 2015. Beijing issued an orange alert for heavy smog 30 November, the highest level this year. Authorities in the Chinese capital warned of 'severe pollution' and advised the capital's 20 million inhabitants to stay indoors. (Photo by How Hwee Young/EPA)

Michael Read, director of Flight Operations from New Zealand-based Martin Aircraft Company, flies a Martin Jetpack during a demonstration at a water park in Shenzhen, China December 6, 2015. KuangChi Science Ltd, a Hong Kong-listed Chinese company and investor of Martin Aircraft, will sell the flying machine in mainland China for 1.6 million yuan ($249,902), according to the company. (Photo by Bobby Yip/Reuters)

A woman and a child walk past the remains of collapsed houses damaged during the April 2015 earthquake, in Bhaktapur, Nepal March 18, 2016. The two devastating earthquakes that struck Nepal last year killed almost 9,000 people across the country. Inside the Kathmandu Valley almost 2,000 died, and some of the area's most important cultural and heritage sites were completely destroyed. As Kathmandu inhabitants prepare to mark the one-year anniversary of the event, thousands are still displaced and millions are living in temporary shelters. (Photo by Navesh Chitrakar/Reuters)

An employee walks near a rotary dredge which works on the coal face of the Borodinsky opencast colliery, near the Siberian town of Borodino, east of Krasnoyarsk, December 9, 2014. The Borodinsky colliery, 9 km (5.6 miles) long and more than 100 meters (328 feet) deep, annually produces more than 20 million tons of coal and is considered to be the biggest opencast coal mine in Russia, according to official representatives. (Photo by Ilya Naymushin/Reuters)

A girl wearing a face mask as a precaution against the coronavirus walks past a display of garments at a market in Bengaluru, India, Saturday, January 9, 2021. India will kick off the coronavirus vaccination drive on Jan. 16 to stem the pandemic in the world's second-most populous country. A Health Ministry statement says that priority will be given to the healthcare workers and the frontline workers, estimated around 30 million. (Photo by Aijaz Rahi/AP Photo)

In this December 8, 2020 file photo, Venezuela's President Nicolas Maduro playfully sprays a journalist with disinfectant as he exits a press conference at Miraflores Presidential Palace in Caracas, Venezuela, amid the new coronavirus pandemic. Attorneys for the cash-strapped government blame the impact of U.S. sanctions for its inability to make an initial $18 million down payment to the United Nations for doses of the U.N.-supplied vaccines, whose deadline has already passed. (Photo by Matias Delacroix/AP Photo/File)

A Guarani boy pets a puppy in the Mata Verde Bonita village, in Marica, Rio de Janeiro state, Brazil, Thursday, February 25, 2020, where healthcare workers are making the rounds with coolers containing doses of China's Sinovac COVID-19 vaccine as part of a mass immunization program aimed at inoculating all of Rio's 16 million residents by the end of the year. (Photo by Bruna Prado/AP Photo)

A child jumps to touch lanterns hung on a tree ahead of the Chinese Lunar New Year celebrations in Beijing on Thursday, January 16, 2020. The world's largest annual migration begins this week in China with millions of Chinese traveling to their hometowns to celebrate the Lunar New Year on Jan. 25 this year which marks the Year of the Rat on the Chinese zodiac. (Photo by Ng Han Guan/AP Photo)