The atmosphere of Earth, as seen during sunset in May of 2010 from the International Space Station. The ozone in our stratosphere is a vital ingredient in protecting humans from high-energy, ionizing ultraviolet radiation. Image credit: NASA / ISS.

Sorry, Earth, The Ozone Layer Isn’t Healing Itself After All

The hole in the ozone is shrinking, for sure, but to assess the whole layer, you need to look at the whole Earth.

Throughout the history of life on Earth, there’s been a little-noticed helper: a thin but important layer of ozone in our planet’s stratosphere. Transparent to visible light, this trioxygen molecule isn’t the type you breathe, but rather successfully absorbs incoming high-energy ultraviolet light. Without the ozone layer, this light would propagate down to the surface, where it’s capable of breaking organic bonds and working to counteract the natural life processes we hold so dear. Inadvertently, the widespread rise in chlorofluorocarbons (CFCs) and their use in aerosol cans began to destroy the protective ozone layer, and some 30 years ago, humanity banded together to virtually eliminate CFC use. We thought the hole would close and the problem would solve itself. But a new study, surveying a part of the ozone layer that hadn’t been examined before, shows that the overall problem hasn’t improved in 20 years.

The ozone layer in Earth’s stratosphere protects life on the surface from harmful ultraviolet radiation. While CFCs significantly damaged this layer, it was thought that ceasing those emissions would lead to a general recovery. This may not be the case at all. Image credit: NASA / Smithsonian Air & Space Museum.