Emily Kwong

polar vortex, which results in this seasonal cycle that has its rhythms.

Now, let's go back in time when scientists really started noticing the ozone layer was changing over Antarctica beyond what was typical for the seasonal rhythm.

And these researchers went on an expedition to Antarctica to figure out why.

It's like their Achilles heel.

I read that one chlorine atom can destroy over 100,000 ozone molecules.

Yeah, definitely.

What the heck were we doing in the 50s and 60s that created this abundance of chemicals in the atmosphere?

But I'm, like, curious, like, how did stuff made on Earth produce molecules that got all the way up there?

Because the stratosphere is miles above our heads.

It's, like, where planes fly.

Like, how could chemicals travel upwards that high?

Oh, so they hang out a long time.

What an accumulation of forces that led to this problem.

Okay, so what did scientists do in response?

Because obviously today the ozone is okay.

So why?

What happened, ultimately, to save the world?

Right, and that is how we get to the point now where the ozone layer is doing well.

I read it's the fifth smallest since the crisis.

Why hasn't the ozone fully thickened over Antarctica?