August 17 4, 2023
By Jackie Appel

The Hole in the Ozone Layer Is Opening Early This Year. That Shouldn't Happen.

mkf//Getty Images

• The hole in Earth’s ozone layer is opening early this year.
• While the hole has healed somewhat since the 80s and 90s, it still goes through a cycle of opening and closing every year.
• The preemptive expansion is due to a huge undersea volcanic eruption from last year, and may further warm the Southern Ocean, which has already experienced heavy negative effects from climate change.

Does everyone remember the hole in the ozone layer? Before every other symptom of climate change became so readily apparent to us, the hole in the ozone layer over Antarctica was our strongest indicator that we were doing something to our planet—something that was having serious negative impact.

Luckily, the Montreal Protocol—an international treaty centered on protecting and repairing the ozone layer—went into effect in 1989 and staved off further emission of chemicals known as ozone-depleting substances. Since then, the ozone layer has begun to heal, and should be completely back to pre-1980s levels by 2066.

Good news! Unfortunately, however, we’re not all the way to healed just yet. In the meantime, the hole in the ozone layer has gone through—and continues to go through—generally predictable cycles of growing and shrinking. The hole generally begins to grow in September, and shrinks back down in the winter months.

But this year seems to be a bit different. Following the now more-to-be-expected bad climate news trend, the hole in the ozone layer has begun to open early this year.

The cause—amazingly, not us. This one we can put down to purely natural causes. Last year, the the Hunga Tonga-Hunga Ha’apai volcano erupted in a truly massive explosion. It set off a large tsunami, caused a huge sonic boom, and jettisoned a frankly ridiculous amount of water vapor into the atmosphere. Because of the eruption, the atmosphere currently holds about three times more water vapor than usual. And that last point is now having a lasting impact on our ozone layer.

The growing and shrinking cycle of the hole in the ozone layer is powered by upper atmospheric clouds. Water vapor that forms these clouds can form reactive chemicals that destroy ozone, and as the clouds are more or less prominent in certain parts of the year due to temperature fluctuations, the hole fluctuates right along with them. But inject a whole bunch of additional water vapor into the ozone layer, and you have a problem. Researchers knew there were going to be long-term effects from the amount of water vapor launched into the atmosphere, but we’re just not finally seeing them in action.

Luckily, this isn’t a permanent situation, but it still may have damaging effects to parts of the world. Specifically, researchers are concerned about the Southern Ocean, which has already experienced serious effects from climate change. Especially with arctic sea ice at an all-time low for this time of year, a hole in our atmospheric sunscreen right above the region isn’t exactly the best thing we could have hoped for.

While we didn’t cause this particular bummer, we are definitely the main drivers of the general climate crisis that this is stacking itself upon. Perhaps if we weren’t already facing record temperatures, the hole in the ozone layer widening early may not be as big a deal. But if we want to prevent things like this from mattering so much in the future, we have a lot to do to make the baseline conditions better.