Emily Kwong

So thank you so much for coming on the show.

I'm Emily Kwong.

And I'm Regina Barber.

Thank you for listening to Shortwave, the science podcast from NPR.

You're listening to Shortwave from NPR.

Hey, Shortwavers, Emily Kwong here with a love letter to the layer of the Earth's atmosphere that acts like a sunscreen.

I'm talking, of course, about ozone.

Without ozone, that would be impossible to live on Earth.

This is atmospheric scientist Irina Petropadlovskikh.

The ozone is a layer of the stratosphere with a high concentration of ozone molecules, each one made out of three oxygen atoms.

To form, ozone needs sunlight, which bursts oxygen apart.

You know, the O2 version we breathe.

And then each single atom of oxygen can then connect with another O2 to form our girl O3, a.k.a.

ozone.

But sunlight can also destroy ozone, and the balance generally depends on the season.

But starting in the 1970s, something weird happened.

Remarkable loss of ozone that occurs over the Antarctic in October.

A lot of people call it the ozone hole, but it was really more of a thinning.

Scientists launched weather balloons to study its size, and they found something shocking.

High levels of two chemicals, chlorine and bromine, were breaking down ozone faster than it was being made, letting in the kind of radiation that causes cancer, crop failure.