Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

Megan Hall: Take a look out your window. What color is the ground? It turns out that what you see plays a big role in the speed of climate change. 

Here to explain are Isha Chawla and Fatima Husain from our Possibly team. Welcome, Isha and Fatima!

Isha Chawla: Hello!

Fatima Husain: Hi, Megan!

Megan Hall: So, tell me — what does the color of the ground have to do with climate change?

Isha Chawla: Megan, think about it this way: what would you rather wear on a really hot and sticky summer day — a black t-shirt or a white one?

Megan Hall: White! Black would only make the heat worse.

Isha Chawla: Yes, and that’s because lighter colors, like white, are better at reflecting light. So, they absorb less heat. 

Fatima Husain: Think of the earth like your body on a hot day. If it’s dressed in white, it reflects incoming light and doesn’t heat up as much as if it’s dressed in dark colors. 

Baylor Fox-Kemper: when the sun's light arrives at the earth, it might be absorbed, or it might be reflected away. 

Isha Chawla: That’s Baylor Fox-Kemper, an oceanographer and professor at Brown University. He says the Earth absorbs more of the sun’s energy in spots where the ground is a darker color.

Fatima Husain: Scientists call how much an object reflects energy its albedo. 

Megan Hall: So, do we want more albedo or less? 

Isha Chawla: In the case of climate change, higher albedo is better! We want the land covered with colors that bounce light away instead of absorbing it. 

Fatima Husain: Places like the North and South Pole and snow-covered mountains have high albedo. That’s because the white snow and ice are better at reflecting light. 

Isha Chawla: But here’s the tricky part — what is climate change doing to those spots?

Megan Hall: Ohhh! Melting the snow and the ice! 

Isha Chawla: Right, and that gives way to reveal much darker colors.

Megan Hall: Which absorbs more heat!

Isha Chawla: Exactly! And Baylor says this creates a positive feedback loop. 

Baylor Fox-Kemper: And I don't mean positive in terms of good.

Fatima Husain: For instance, let’s say you start with a spot in the Arctic ocean that’s covered in snow and sea ice. Because it’s white, it reflects about 85% of the sunlight that falls on it.  

Isha Chawla: But with global warming, we have almost no ice left in the summer. That white has been replaced by navy blue water that reflects only about 7% of the sunlight.  

Baylor Fox-Kemper: If you make the earth warmer, you reduce the amount of sea ice, and then you absorb more, which makes it warmer, which makes it reduce the sea ice, which makes it warmer still. 

Fatima Husain: And that positive feedback loop amplifies the effects of climate change. 

Megan Hall: Isn’t there some way we could help with this problem? Like, what if we stretched a bunch of white tarps across the ocean? 

Isha Chawla: Actually, at the local scale, cities are beginning to take albedo seriously. New York has painted almost 10 million square feet of rooftops white to try to help cool down its buildings.

Fatima Husain: On a global scale, manipulating our environment in that way used to be dismissed as science fiction. But, as the effects of climate change get worse, scientists are starting to think about it more and more. 

Megan Hall: Sounds like a good idea for another Possibly Episode!

Fatima Husain: I’m up for it if you are, Isha! 

Isha Chawla: Let’s do it! 

Megan Hall: Great! Thanks, Isha and Fatima! 

That’s it for today. For more information, or to ask a question about the way you recycle, use energy, or make any other choice that affects the planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.