Why is the Ozone Hole Getting Smaller?
Narration: Joy Ng
Good news! Scientists say the Antarctic ozone hole is on the road to recovery.
The amounts of ozone-depleting substances grew rapidly in our atmosphere in the 80s and early 1990s, but had stopped growing in late 90s because of the 1987 Montreal Protocol.
As levels of these manufactured chemicals have decreased in the last 14 years, the ozone hole has seen a slight improvement.
Today, satellite observations by NASA and NOAA show the peak size of this year’s ozone hole measured 9.3 million square miles—an area roughly the size of North America.
This area is smaller than holes observed in past years and significantly less than the largest hole on record.
But scientists say the decrease of ozone-depleting substances isn’t the only factor that has contributed to these improvements.
Rising temperatures in an upper layer of the atmosphere known as the stratosphere may also play a role.
Colder temperatures in the polar regions have been shown to promote ozone depletion, while warmer temperatures lead to increased ozone.
Years with warmer temperatures generally had smaller holes, while colder temperatures had larger holes.
So how much of the ozone hole’s recovery is due to a rising temperatures versus decreasing levels of manufactured chemicals?
Scientists are looking to answer this question.