CNN News:新冠疫情封城后 全球多座城市空气质量明显改善

New Delhi, the capital of India, is usually near or at the top of the list when it comes to the world's most polluted cities. But from March 23rd to April 13th of this year, it saw a 60 percent reduction in a certain type of pollution that it saw in the same period last year.
In the capital of South Korea, there was a 54 percent reduction in the pollutant. Wuhan, China; Sao Paulo, Brazil; Los Angeles, California, all of these cities saw a double-digit improvement in air quality and this is all according to one report who's release was timed to coincide with Earth Day yesterday.
It looked at air quality information recorded from government monitoring stations in 10 cities. The cleaner air was a silver lining to the lockdowns of the coronavirus pandemic. To date, the disease has been contracted by more than 2.5 million people around the world. And researchers say almost 7 percent of that number have died from COVID-19.

Global efforts to keep people away from each other have forced workers, students and would-be travelers to stay home. That means there are fewer planes in the air, vehicles on the road and factories in production. On the plus side, scientists say social distancing has been effective in slowing down the spread of coronavirus. On the minus side, millions of people are out of work and many nation's economies have been badly damaged.
A U.S. government spokeswoman says, the trends in cleaner air are temporary and that things will go back to the way they were when the coronavirus crisis has passed. And researchers in the air quality report say keeping factories closed and cars off the road will not be a realistic solution to the world's pollution problems. But the lockdowns and shutdowns have changed the way cities look and how they pollute.