Guest: Julia Rosen | Journalist
Category: 🌳 Carbon Capture | Grasslands
Podcast’s Essential Bites:
[2:15] JR: "[The grasslands] are being destroyed faster than we are losing forests. In the US, we've lost about half of our grasslands [...] and then amongst certain types of grasslands, so the tall grass prairie, which is what grew in sort of the wetter parts of the Midwest, there's less than 1% of that left [and] there's less than 1% of the Texas prairies left. [...] So some of those ecosystems are basically gone."
[5:43] JR: "There are scientists who think that [the] expansion of grasslands over the last 20-30 million years helped cool the planet because grasslands are lighter in color than forests and so they would reflect more sunlight. And then also they absorb all this carbon in their soils, taking it out of the atmosphere. And so they could have actually helped drive global cooling, which over the last 20 million years the earth got cooler and cooler [...] until we grew these ice sheets and ended up in the ice age that we're still technically in."
[6:32] JR: "[Some people] describe grasslands as the inverse of the rainforest. What we see at the surface is just these little blades of grass, [...] but underground is this huge network of roots that can go six to eight feet deep. Some of the prairie flowers can go up to 20 feet deep, but really it functionally lives underground. And that's why it's so resilient and so interesting. [...] It's got all these elevate storage organs for the plants, the things that [they] need to survive the winter or to bounce back after a fire or grazing, that's all underground, so it's safe. And then they're photosynthesizing all the time. They're producing all these sugars, and then they're pumping carbon underground all the time."
[10:04] JR: "Grassland ecologists are very alarmed at these efforts [of planting trees in these ecosystems]. [...] Because grasslands appear empty, they seem like an easy place to go out and put some trees. That really damages the grassland if you're actually taking carbon that's very safe underground and then you're putting it in a tree that can burn. And then the other thing is that a lot of these plantations, they're not forests. You're not [...] planting a biodiverse forest of native tree species, you're planting a mono crop of non-native commercially valuable tree species."
[11:45] JR: "Trees have been part of the carbon credit picture from the beginning. Something like 80% of the offsets in California's market are from forest management. But just in the last 5 or 10 years, there started to be carbon credits for grasslands. So if you've got a grassland that's intact, you can sell carbon credits by basically promising not to plow it or develop it."
[11:58] JR: "There's some really interesting research about putting compost on grasslands. There's studies that show that if you increase the diversity of plants in our restored prairie, you can store more carbon. So there's a bunch of things that people are exploring to see if we could increase the amount of carbon that these landscapes can hold. But for now, really a huge one is just leaving the grasslands that exist in place."
Article: "Trees are overrated" (Julia Rosen, 2022)