There's been a sharp drop in air pollution over China since the acceleration of the COVID-19 coronavirus outbreak, and satellites can see it from space.
That old “silver lining” observation certainly applies. The Black Death had a similar affect on Europe I understand; from watching Stephen Fry’s wonderful series , “QI”, (Quite Interesting), and the more recent explosion of a volcano in Iceland that halted airline traffic. The Earth shakes us off like a dog does fleas!