This episode is presented by eBay.

Rob, everyone loves a deal and a bargain from time to time, don't they? Absolutely, mate. And do you know where you can grab a great deal? Talk to me. Where? The eBay app. Yes, you are correct. You didn't need to talk to me. I already knew it. I love eBay. When you're buying, you can discover loads of hidden gems. there's so many items where you think I would have never found that anywhere else.

Then when you're buying, you can discover loads of hidden gems. There's so many items where you think I would have never found that anywhere else. Then when you're selling, it's so simple and most

importantly, free. It's free, Rob. When it's this easy to sell for free and there's great deals

on things you love. You can't help but say when it's eBay. It excludes vehicles and business

sellers. Welcome to Scientific vehicles and business sellers.

Welcome to Scientific American Science Talk posted on September 27th, 2019. I'm Steve Merski.

On this episode, climate change is the most significant public health challenge of our time.

That's Gina McCarthy. She was the administrator of the Environmental Protection Agency during most of Barack Obama's second term as president.

Last year, she became the first director of a new climate center created by the Harvard

School of Public Health.

It's called Sea Change, the Center for Climate, Health, and the Global Environment.

Scientific American Associate Editor Andrea Thompson spoke with McCarthy by phone

just prior to this past week's UN Climate Action Summit.

I wanted to get your thoughts on whether you do think there is maybe the tide is kind of shifting on our desire to actually take concrete action to combat climate change.

And, you know, why you think that that might be happening now and if it can be sustained.

I do think that we are at a bit of a turning point.

I think everybody has different views on why that's the case,

but clearly the science is getting more urgent.

I think you have now a new generation of young people.

They're just not letting the rest of us off the hook anymore.

They don't seem to have the same kind of reluctance to embrace the science, and they're

...