I admit, when I heard that today was International Day for the Preservation of the Ozone Layer, my initial reaction was confusion. Wait, I thought. The ozone layer gets its own day? I thought we already fixed that.
Back in the 90s, we heard a lot about the holes in the ozone layer and how bad they were for the environment and for our own health. Global warming and the melting of the ice caps hadn’t really made it into the headlines in a big way yet, but the holes in the ozone layer were a Big Deal. But then we banned chlorofluorocarbons (CFCs) and the problem was solved. Right?
Well, sort of, but as usual it’s more complicated than that.
First, a quick primer. Ozone is a highly reactive gas composed of three oxygen atoms. It occurs both naturally and as the result of artificial processes. In the lower atmosphere (the parts we breathe), it’s considered a pollutant with multiple adverse effects on plants and animals. Up high, however, in the stratosphere, a thin envelope of ozone screens the earth from most of the sun’s harmful radiation. Without ozone, the sun’s ultraviolet (UV) rays would literally fry the planet and wipe out every living thing.
So yeah, it’s actually pretty important. (I didn’t realize how important until just now when I read that on NASA’s website. Guess it does deserve its own day.)
Natural ozone is formed when sunlight hits molecules of the oxygen we breathe (O2) and splits them apart into individual oxygen atoms (O). Those atoms can rejoin in pairs (forming O2 again) or in triples, forming ozone (O3).
Remember how I said ozone was highly reactive? That three-atom structure is really unstable, falling apart when it comes into contact with elements like nitrogen, hydrogen, chlorine, or bromine. All of these occur naturally, but (and here we get to the crux of things) human activity pumps an unnatural quantity of these elements into the air, destroying ozone molecules faster than they can form.
Thus, holes. And frying.
Nobody liked that idea, so in 1987, everyone signed a global agreement known as the Montreal Protocol. And when I say everyone, I mean it: The Montreal Protocol was the first universally ratified treaty in United Nations history. It went into effect on September 16, 1989, phasing out the use of the major ozone-depleting chemicals worldwide.
And it worked: The ozone layer is actually healing. Scientists estimate that at current rates, it could be completely recovered worldwide by 2060. That’s an astonishing victory.
There’s more to do, of course. There are other chemicals still being used that aren’t great for the ozone layer, and we need to keep an eye out for other potential sources of damage and react quickly if they appear. And, as we’re all acutely aware, we’re not doing anywhere near enough to react to today’s environmental threats.
But the Montreal Protocol is proof that we can come together and make big changes, quickly. We can react decisively and do what has to be done to heal this planet. It can be done. We can do it.
That’s a fact worth celebrating. All day.