Is the ozone hole shrinking? And who in Boulder is keeping track?
At least one thing in the environment seems to be getting better.
The annual ozone layer survey, where Boulder scientists and instruments play a key part, tells us we’re still on track for solving a problem that terrified the world in the 1990s and early 2000s. Back then, headlines and interviews with Southern Hemisphere residents warned of blinded sheep, sickness from unchecked ultraviolet rays in cities like Punta Arenas, Chile, and dangers for Antarctic science stations right under the hole.
Boulder-based NOAA tells us that 2023’s worst day for the ozone layer was only the 12th worst since they began recording in 1979, and that overall it was a “very modest ozone hole.” And remember — this is a hole in the “good” ozone, the one that protects us from sun intensity, not the “bad” ground-level ozone pollution created by a stew of nitrogen oxide, volatile organic compounds and intense summer heat.
So the international chemical ban — the Montreal Protocol — protecting the ozone shield continues to work its science magic. Now if only we can reach the same consensus and rapid action on carbon dioxide.
The ozone hole peaks over the Antarctic during its spring, bringing the Sept. 21 reading this year to a gap of 10 million square miles. The average from Sept. 7 to Oct. 13 peak season was 8.9 million square miles, about the size of North America, in NOAA’s helpful shorthand.
The “very modest” assessment came from Paul Newman, leader of NASA’s ozone research team out of Greenbelt, Maryland. “Declining levels of human-produced chlorine compounds, along with help from active Antarctic stratospheric weather, slightly improved ozone levels this year,” Newman said.