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.
On Possibly, we talk a lot about how cutting beef out of your diet is one of the easiest ways to reduce your greenhouse gas emissions.
But, we’ve also heard about this thing called regenerative cattle grazing that claims to make eating beef more sustainable. Is that true?
We’ve got Nat Hardy and Leo Nachamie to walk us through the answer.
Nat Hardy: Hey Megan!
Leo Nachamie: Hi!
Megan Hall: Remind me—why is beef such a big climate problem?
Nat Hardy: For one, cows burp out methane, which is a really powerful greenhouse gas.
Leo Nachamie: And because of how much beef we eat, there are a lot of cows on this planet. Their bodies take up more physical space than any other mammal on earth—including humans.
Megan: That’s… a lot of burps.
Nat Hardy Yeah… And if you add in the land and fossil fuels used to grow their food, you get a massive impact on our climate, just from cows.
Leo: Every pound of beef creates roughly the same amount of CO2 as driving a gas-powered car for about 100 miles.
Megan: Yikes. So is there any way to cut down on those emissions?
Leo Nachamie: That’s what some advocates of regenerative grazing have been hoping.
Megan: Okay, so what exactly is regenerative grazing?
Leo Nachamie: The idea is to raise cattle in a way that has a lower impact on the environment.
Megan: And how do you do that?
Nat: One way is to mimic the way wild animals feed on America’s grasslands. Like Bison.
Dan Kane: Think of a pre-colonial bison herd moving across the landscape, right? Huge numbers, they’ll come through, graze really hard for a short period of time, and then migrate on, and they won’t return for the rest of the year.
Leo Nachamie: That’s Dan Kane. He’s a soil scientist at Mad Agriculture, which is a non-profit that helps farmers and ranchers transition to regenerative practices.
Nat Hardy: He says that most traditional cattle operations will let their herd loose onto a big swath of land, and kind of just let them munch away.
Leo Nachamie: Which means the grasses can’t catch a break—they get eaten and trampled over constantly.
Nat Hardy: It’s the opposite of what bison do: eat a lot, but don’t return for a year.
Leo Nachamie: With regenerative grazing, ranchers try to mimic the bison by dividing their land into smaller segments, and moving their herd every day or so.
Megan Hall: And that gives the grass a chance to fully recover and grow back?
Leo Nachamie: Exactly.
Nat Hardy: And here’s the crux of it: Some farmers claim that this approach can actually put more carbon into the soil than it takes out.
Megan: Woah. How would that work?
Nat Hardy: We needed some help figuring that out. So we talked to our show’s founder, professor Stephen Porder. He says:
Stephen Porder: The idea there is that, if the animals graze in a way that promotes a lot of plant growth and the plant growth is healthy and has a lot of roots and is robust, that that might actually start to pull some carbon out of the air and store it in the soil.
Leo Nachamie: Plants capture carbon dioxide from the air. When those plants die, most of that goes back to the atmosphere. But some carbon dioxide gets stuck in the soil.
Nat Hardy: So if we can figure out how to get more of that carbon into the soil, by letting the grass grow back, we could lower the carbon hoofprint of beef.
Megan Hall: Okay, that makes sense! So… climate problem solved?
Leo Nachamie: Unfortunately, not quite.
Nat Hardy: Both Stephen and Dan, the soil scientist, have spent their careers knee-deep in the latest research around regenerative grazing. And both of them say the data is just not there. At least not yet. Here’s Dan:
Dan Kane: We’ve got like a set of papers that say, okay. Hey, this looks promising. But when we then shift over to the small number of experiments, where people really tried to kind of control for all these things and really try and are a nice experimental setup, the evidence just is kind of weak.
Leo Nachamie: Basically, we’re a long way from knowing that changing grazing practices has any effect on soil carbon.
Megan: So what’s the takeaway here?
Leo Nachamie: Regenerative grazing can have all sorts of benefits - it can help slow soil erosion, and support more biodiverse grasslands.
Nat Hardy: But when it comes to the carbon question, we shouldn’t count on it to really help with climate change.
Megan Hall: Great! Thanks, Nat and Leo!
That’s it for today. Special thanks to Cameron Leo, who did the reporting for this episode.
For more information, or to ask a question about the way your choices affect our planet, go at ask possibly dot org. You can also subscribe to Possibly wherever you get your podcasts or follow us on social media at “ask possibly”
Possibly is a co-production of Brown University’s Institute for Environment and Society, Ocean State Media, and WBRU.
