Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall.
When I was growing up, I remember hearing about a hole in the ozone layer.
It was a big deal. But I don’t really hear about that issue anymore. Is the ozone layer still in danger, and what happened to the hole?
We had Harrison Katz and Janek Schaller from our Possibly team look into this.
Harrison Katz: Hi, Megan!
Janek Schaller: Hello!
Megan Hall: So, why don’t I hear about the ozone layer anymore?
Harrison Katz: Well, first, let’s talk about what ozone is.
Janek Schaller: It’s a gas made of three oxygen atoms bonded to one another. It can actually be formed naturally, or as a result of pollution.
Megan Hall: What’s the difference?
Harrison Katz: Ozone that’s formed naturally is high up in a portion of the atmosphere called the stratosphere, which is where planes fly. That’s what we call the “ozone layer.”
Janek Schaller: The other place you can find ozone is close to the ground. It forms because of pollution. Think smog.
Megan Hall: So, we don’t really want that kind of ozone.
Harrison Katz: Right. But, without the ozone layer, life wouldn’t be possible.
Janek Schaller: That’s because the ozone layer absorbs about 98% of the ultraviolet radiation from the sun–
Harrison Katz: That’s the stuff that gives us sunburns and hurts our eyes
Janek Schaller: Sunburns are painful already, and they’re caused by the small portion of radiation that escapes the ozone layer. So, we can’t live without it.
Megan Hall: Wow, so the ozone layer protects life as we know it. What happened to it?
Harrison Katz: Well, when people in the 1980s doused themselves in hairspray to achieve their iconic “big hair” look, they were actually releasing chemicals called chlorofluorocarbons (Clor-o-Floor-o-Carbons), or CFCs, into the atmosphere.
Janek Schaller: CFCs are also used in refrigeration and aerosols. When they enter the atmosphere, either from hairspray or from leaks in refrigerators and other devices, they drift upward and destroy molecules of ozone.
Harrison Katz: In the 1980s, these CFCs were not well-regulated, and most devices that used them weren’t disposed of properly.
Janek Schaller: Once we realized that CFCs were dangerous, scientists set out to see how much damage had been done.
Harrison Katz: And they were shocked! They found a seven million square mile area over Antarctica with way less ozone than would naturally occur.
Megan Hall: That sounds terrifying! Why isn’t anyone talking about this anymore?
Janek Schaller: Well, that’s because leaders around the world took action!
Harrison Katz: In 1987, governments agreed to a series of international regulations called the Montreal Protocol, which required countries to cut their CFC production in half by 1998.
Janek Schaller: Protecting the ozone layer was seen as such an important goal, that to-date, the Montreal Protocol is the only treaty to have been signed by every country on Earth.
Harrison Katz: As a result, the ozone levels are almost back to normal.
Megan Hall: So we don’t need to worry about the ozone layer anymore?
Janek Schaller: Well, CFCs stay in the atmosphere for a long time, which means some damage from the 80s is still occurring today, but it’s mostly controlled.
Harrison Katz: As long as we all keep abiding by the treaty, this is a global environmental problem that’s largely taken care of.
Megan Hall: Great! Thanks, Harrison and Janek!
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Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.
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