Whatever Happened to the Hole in the Ozone Layer?


Image credit: NASA

Let's start with the bad news: Remember that hole in the ozone layer that scientists discovered over the Antarctic in 1985? The one we worried would give us all skin cancer and cataracts with its unshielded bursts of UV rays? It’s still there.

It gets worse. Scientists announced that a new hole opened up in early 2011—this one over the Arctic. So it’s still a rough time for the stratosphere, the layer of the atmosphere that helps block out some of the sun’s UV rays.

But here’s the good news: we’ve got a handle on the problem.

When the first hole came to light, world leaders moved quickly. Through the Montreal Protocol of 1987, several nations nixed the production of ozone-killing chlorofluorocarbons. Saving the ozone was literally the first thing the whole world ever agreed on: A treaty banning CFCs was the first agreement ever to be ratified by every country in the United Nations.

As the level of atmospheric CFCs began to drop, the ozone layer started repairing itself. While the going is slow—a lot of the CFCs we released in the 1970s and 80s are still floating around doing damage—scientists hope the ozone layer will be back to normal by the end of this century.

Oddly enough, the depleted ozone layer did have one positive side effect: It helped curb global warming. The thinned ozone of the Antarctic led to brighter clouds that reflected some of the sun’s radiation away from Earth. Cutting out this effect may give global warming a slight boost, but scientists are quick to note that we’re far better off with a healthy ozone layer.

This article originally appeared in the Jan-Feb 2012 issue of mental_floss magazine.