New Delhi was engulfed by hazardous smog as air quality levels plummeted after India’s national capital celebrated the festival of Diwali without a blanket ban on firecrackers for the first time in ...

A motorcyclist in Los Angeles prepares to turn while driving along a street engulfed in a thick haze combined by fog and smog in 1958.Bettmann / Getty For much of its history, the city of stars could ...