This is Science Friday. I'm Ira Flato. Earlier this week, a lake formed by the melting of Alaska's

Mendenhall Glacier threatened to flood one of the state's largest cities, its capital, Juno.

The flood reached a record-breaking crest of nearly 17 feet, and it had the potential to be catastrophic.

But you know what? After years of flooding, Juno was prepared for this one, and their preparations may have saved many homes and lives.

Here to discuss this and other climate news of the week is Casey Crownhart, senior climate reporter for MIT Technology Review in New York.

Casey, welcome back to Science Friday.

Thanks.

Always so wonderful to be here.

Tell us about this flood.

What happened?

Yeah, so like you said, this was a pretty big glacial flood in Alaska.

This is kind of becoming more common because of climate change. Basically,

what happens is as glaciers melt, they often kind of retreat uphill and they leave behind these

glacial lakes, which are these lakes of glacial meltwater, and they often have walls made

of like loose dirt and rock and ice. And those can break, which sends water downhill sometimes

pretty quickly. Since 1990, the number and area and volume of these lakes around the world have all grown by about 50%.

So we're seeing more of this as, you know, the climate warms up.

Also, like you mentioned, the good news is that this community was pretty prepared for this.

So while we did see record-breaking floods, there was very little damage and very little by way of rescue efforts needed.

When you say it was prepared, what do you mean by that?

Yeah, so this has become an issue in this area pretty much every year since 2011.

They've seen that this glacier causes flooding like this. It has gotten

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