According to real-time pollution data, Kathmandu became the most polluted city in the world on Monday. In the afternoon, ...

For more than two months, the city of Wuhan, China, was sealed off from the outside world. Flights in and out were canceled. Train and bus routes were suspended. Highway entrances were blocked.

You turn a corner and there it is: that traffic-stalling on-off of crimson brake lights animating a staccato driver up ahead.