NPR.

This is the indicator from Planet My, I'm Darym Woods.

And today we've got a story about the most important tool that the Environmental Protection

Agency has for cracking down on greenhouse gas emissions.

It's been around for a little over a decade, and that tool is a single number.

It's expressed in dollars.

It's called the Social Cost of Carbon, and it represents all the costs to humanity

of emitting one ton of carbon dioxide into the atmosphere.

So this social cost of carbon includes the cost of lost crops because of climate change.

It includes the lost wages when people can't safely work outside, and the cost of climate

related deaths.

This number has moved around over the last few years.

It was lower under the Trump administration, and right now it's $51.

But most climate experts say that number is probably an underestimate, and that's why

the EPA is now proposing to raise it to $190.

But how the EPA got to that much higher figure is an ethics nightmare.

Our friends at shortwave, NPR's Daily Science podcast, recently didn't episode on this,

and we just had to share it.

So after the break, shortwave co-host Aaron Scott talks with the NPR climate correspondent

Rebecca Herschö.

Okay, Rebecca Herschö, how can this one number be such a powerful tool for cutting emissions?

Because every major regulation is required to go through something called a cost-benefit

...