“The hole should vanish entirely by 2070 and should start to recover in the next decade,” says one of the lead scientists on the research, Susan Strahan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The size of the ozone hole above Antarctica, a region in the upper atmosphere characterized by very low ozone levels, has peaked in recent years, covering roughly 8.1 million square miles (21 million square kilometers) to 10.4 million sq. mi. (27 million sq. km.)—an area larger than South America.

More than 20 years ago the Montreal Protocol limited the use of ozone-depleting chemicals, which had left a visible wound in the Earth’s ozone layer. But since they have a life span of more than