We've been monitoring a disturbing hole in the ozone layer above the South Pole since the 1980s. Good news: NASA and NOAA scientists announced on Monday that the seasonal 2019 hole is the smallest since we've been keeping records. Bad news: That doesn't mean it's fixed.
"It's great news for ozone in the Southern Hemisphere," said NASA scientist Paul Newman. "But it's important to recognize that what we're seeing this year is due to warmer stratospheric temperatures. It's not a sign that atmospheric ozone is suddenly on a fast track to recovery."
Scientists sounded the alarm on the ozone hole in the '80s, warning about the loss of what NASA describes as an atmospheric version of sunscreen. The ozone layer blocks ultraviolet radiation from the sun and helps keep the Earth habitable for life.
The 2019 hole hit its maximum size of 6.3 million square miles (16.4 million square kilometers) on Sept. 8. It normally expands to cover an area of around 8 million square miles. The difference this year was due to unusual warm weather patterns that kept the hole in check. "There is no identified connection between these weather patterns and climate change," said NOAA in a release on Monday.
NASA and NOAA use a combination of satellites and weather balloon data to track the ozone hole, which typically hits its peak around this time of year before shrinking once again. The agencies also saw similar warm weather patterns and smaller-than-usual holes in 1988 and 2002.
There have been global efforts to reduce the use of substances, including some types of aerosol products, that can damage the ozone layer. We're still looking at a long timeline for improving the situation. NASA revealed the first direct proof of ozone recovery in early 2018, but said the healing process is expected to take decades.