Big hole in ozone getting smaller

Here’s a rare piece of good news about the environment: The giant hole in the Earth’s protective ozone layer is shrinking and has shriveled to its smallest peak since 1988, NASA scientists said.

The largest the hole became this year was about 7.6 million square miles wide, about 2½ times the size of the United States, in September. But it was still 1.3 million square miles smaller than last year, scientists said, and has shrunk more since September.

Warmer-than-usual weather conditions in the stratosphere are to thank for the shrinkage since 2016, as the warmer air helped fend off chemicals like chlorine that eat away at the ozone layer, scientists said. But the hole’s overall reduction can be traced to global efforts since the mid-1980s to ban the emission of ozone-depleting chemicals.

“Weather conditions over Antarctica were a bit weaker and led to warmer temperatures, which slowed down ozone loss,” said Paul Newman, chief Earth scientist at NASA’s Goddard Space Flight Center in Maryland. “This is a year in which the weather conditions led to better ozone (formation).”

The news comes just after the 30th anniversary of the hole’s discovery, which led to the 1987 Montreal Protocol — a landmark international agreement that led to major global efforts to phase out the use of ozone-depleting chemicals.