Dr. David Montgomery, a geomorphologist who studies the surface of the earth, discusses soil and why the ground beneath our feet is so important in our climate solutions.
Dr. David Montgomery, a geomorphologist who studies the surface of the earth, discusses soil and why the ground beneath our feet is so important in our climate solutions.
To learn more about Dr. David Montgomery, visit https://www.dig2grow.com/
To listen to more from his band, Big Dirt, check out:
https://wanderinginfinityproductions.bandcamp.com/ & https://www.youtube.com/channel/UCEa9oYJ1UkhYtfecVrATA4w/playlists
1 Point 5: A Kids Climate Justice Podcast
S1EP10, What is the Soil's Role in Taking Carbon From Our Atmosphere?
[INTRODUCTION]
Zanagee: Hello and welcome to 1 Point 5: A Kids Podcast About Climate Justice! I’m Zanagee Artis
Olivia: And I’m Olivia Greenspan.
Zanagee: And this is 1 Point 5, a show where we delve into the challenges facing our planet – and the solutions to those challenges ;) – with scientists, youth activists, and other environmental leaders who have experienced the realities of the climate crisis firsthand.
Olivia: So far in this section on climate solutions, we’ve covered water-based solutions with Dr. Porcelli and Indigenous sovereignty with Jaike Spotted Wolf. This week, we’re moving on to earth – the land beneath our feet. Yes, this week on 1 Point 5 we are speaking with geomorphologist Dr. David Montgomery, who also plays in that band you heard in the beginning, Big Dirt! And a geomorphologist is a scientist who studies the physical features of the surface of the earth - like soil!
Zanagee: With Dr. Montgomery we’ll discuss how our land and soil is affected by the climate crisis and what we need to do about it. We’ll answer questions like why the ground beneath our feet is so important to the impacts of climate change, how earthworms and other microbes contribute to the health of our soil, and what chocolate cake can teach us about healthy soil.
Olivia: Let’s dig into this conversation with Dr. Montgomery.
[MEET THE GUEST]
Zanagee: We had a thematic intro for you today, that song was Pebble Mine, by the band Big Dirt!
Zanagee: Today we're going to be talking about earth and the reference to land and soil. And we would love to get into a conversation about why is the ground beneath our feet so important for the impacts of climate change?
Dr. Montgomery: Yeah, that's a really good question because I mean, when we think about climate change and we think about, you know, us pumping carbon dioxide into the atmosphere. Our minds don't immediately go beneath our feet to think about the soil. You have to kind of think about the connections and understand them. But if you look at the total amount of carbon that's in the atmosphere, there's about twice as much in the world.
So the soil is a really large reservoir of carbon on this planet. And of course plants like that. The trees behind me are another big reservoir of carbon. Um, but there's an awful lot of carbon in the ground beneath our feet in the form of soil organic matter, which is basically a shorthand for dead stuff.
Uh, plants that used to be alive that are now dead and the remains of animals. Um, and that organic matter is actually really important for feeding the life in the soil, which helps to cycle nutrients. Back to in a moment, but also to how we grow our food and how we nourish ourselves. Um, and the connection to the climate comes in.
Because if you think about what, you know, nature actually evolved a very efficient system for pulling carbon out of the atmosphere and it's called photosynthesis. It's what plants do to feed themselves. Um, and when that, when plants capture carbon from that in the form of CO2, from the atmosphere, their bodies, uh, that way when they die, that carbon is still in their bodies. And that's where the carbon that's in the ground. That twice as much in the ground, then as in the atmosphere came from once living things. And so we can actually, if we manage our plants right, and we manage our farms, right. We can use farming to pull carbon from the atmosphere. And park at below ground in a way that will build soil fertility.
And so not only help reduce the climate impact of human activities, you know, our fossil fuel use in particular, but it could also help rebuild the fertility of the world's farmland, which will help us feed the world. So I'm excited about the potential for thinking about the connections between soils and climate and, and the health of societies, because it's putting more carbon in the ground using certain farming practices and building the health of our soil.
Really is a win-win for the climate and for people, um, and for the environment as well, because it can help us get off that use fewer agrochemicals. Um, now that said, restoring the world, soils is not going to solve the climate problem, but it could be one step towards helping to do that. And it's, it's, it's one of those connections that most people don't think.
Does, it's not that intuitive. You have to think about plants pulling carbon from the sky, sending some of that carbon to leak out of their roots, to feed microbes in the soil. Then when the plants die, the microbes recycle it. Um, but so there's, there's connections that we can study and learn and understand that can help us inform how we live on the world in a way that will help the land, uh, make future generations of human, of humanity, prosperous and healthy.
Zanagee: Wow. That's all very interesting. And I think, um, makes me think about all the different environments is that we often and pay attention to these large mammals and our oceans and savannas and all these things. But it really sounds like soil is like this really micro environment where there's so much different life happening that no one can even see and people don't really think about.
And so that's really interesting. Um, and people are listening or like me as a kid, uh, I played outside a lot and I used to do lots of digging in the dirt, which was probably now I know probably soil. Um, but when you're digging, um, you might come across earthworms. And so we would love for you to share about why earthworms and all these other microbes and other organisms that are life in the soil.
Um, why are they important for the planet and.
Dr. Montgomery: Yeah, that's a great standing organisms. I mean, they, they seem really simple, right. And when we think about them, but they do an incredible amount of work because they essentially, um, merge the mineral matter and organic matter in their bodies as they ingest plant matter.
And, and soil they'll merge that comes out, the backend of a worm is actually incredibly good for them. You can think of them as like miniature cows that are out fertilizing the soil from the inside out, um, through, through their manure, uh, uh, called worms God's Plowman because they churned and worked the soil of England.
And he calculated that the soils of England got sort of passed through the body of a worm about once, you know, any particle on at about once every a hundred or 200 years. So over long times over geologic time.
Zanagee: When Dr. Montgomery says, “geologic time”, he’s referring to a way of dating Earth’s timeline in periods that can span many millions of years.
Worms are essentially churning and mixing the soil and mixing that frontier between geology and biology and getting those minerals into circulation in the plant world so that they can then cycle on up to the animal world and the human.
So worms are part of that in a way they're part of the natural infrastructure, right?
Olivia: Infrastructure refers to things like roads, bridges, and buildings. So, natural infrastructure refers to the structures that make up our natural world, like soil, worms, and trees.
This planet that helps maintain the viability of life on the continents. And yet we think of them as these lowly life forms and you know, these, these, um, uh, but they're, they're, they're fascinating when you look at what they actually do collect actively individually, they're kind of boring, but, uh, what they do is pretty cool and amazing when you integrate it.
And they're only one example of the kind of life forms in the. That do the kind of work, the heavy lifting of cycling nutrients, getting things like zinc that we need in our bodies. And it's actually, uh, you know, an important micronutrient for bolstering our immune system. Something that's particularly important today.
More from our conversation with Dr. Montgomery after this quick break.
[BREAK]
Olivia: Welcome back to One Point Five, a Kids Podcast About Climate Justice. Let’s return to our conversation with geomorphologist and musician Dr. David Montgomery.
Dr. Montgomery: Fungi in the soil, uh, help get zinc out of the soil and into plants by forming partnerships with the root systems of plants, where the plants will. Uh, sugars, uh, carbon rich compounds. They make through photosynthesis. They'll trade those two to fungi in exchange for minerals, that the fun guy mine out of the soils and connect their fungal hyphae, which is basically the roots of the fungus.
They connect to plant roots and there's a two way trade. Uh, so there's all these symbiotic, mutually beneficial relationships in the soil that are happening that are out of sight out of mind, because we don't see in the soil. And a lot of it's happening with microbes that are invisible to our eyes. but if you look at the, sort of the, the plants and the pollinators and the garden behind me are the hummingbirds that may occasionally flying to the view here.
Those kinds of symbiosis between pollinators and plants were all very well aware of. But we're not so aware of what's happening under the ground, but there's total parallels with what's happening in that hidden world of nature beneath our feet. It's just that we've only recently kind of unlocked the code and started to understand all the chemical signaling and the exchanges that allow soil life to benefit, uh, the plants, um, including our major crops.
Um, and that's how farming practices can actually influence soil, fertility, soil, health, and life as well. In a way you can think of soil as one of the last scientific frontiers, where we're still learning and understanding all those connections between other life forms and ourselves. And some of our misconception modern world have colored our farming practices in way in ways that degrade the soil and its fertility over the long run.
Um, so it's an exciting area to go into. People are interested in microbes and soils. You know, there's a great career to be had in that going forward because it's incredibly important.
Olivia: You too, could be a geomorphologist. Yes. Which would be a cool title.
So also, um, want to talk about things that kids can do. And so, like I said earlier, I used to play. All that stuff. And wondering if there are ways for kids to explore the carbon levels in their local soils. And also if they can learn about what the color of the soil can tell them about the soil health.
Dr. Montgomery: Yeah, no, that's a great question. Um, you know, the, the, the, the simplest metric for gauging soil health, it's sort of like two metrics I'll offer as the simple ones. One is, is there life in it? You know, when, if you dig into it, are there. Yeah. Do you think scurry, do you see things scurrying out of your way as you dig your hand into the soil?
Um, there's, there's very little in the soil that can actually hurt you. Um, dirty, as we might think it is. There's very little that can actually hurt us. And a life filled. Soil tends to be a healthy soil. So if you dig into the soil and there's like nothing, there, no nothing living there. It's probably not in good shape.
Um, and the soil and the yard behind me was that way when we bought our house. Now, if you dig into the soil, like there's like you get a fist full of worms, Um, the other metric, uh, other than just looking for life, uh, is essentially the color of the soil. Uh, khaki colored and gray colored soils, really light toned soils don't have much organic matter, the darker the soil, the better, um, the, that soils that look more like chocolate cake than like khaki, California beach, sand, or healthier soils.
So, you know, you can roughly. Scientific studies that have documented that, you know, the carbon content of darker colored soils is higher than lighter colored soils, you know, in the same climate, in the same region, with the same pair of material, the same rocks that they came from. So you can get a loose feel for how healthy the soil is in your neighborhood, by looking at the color of it.
Um, if you really want to get, um, a much more formal and scientific about it, Is take a sample of soil on, and basically put it in an oven overnight at about a hundred degrees and basically combust all the organic matter in it. And if you weigh the soil beforehand and you weigh the soil after that, we'll tell you how much you lost, which tells you how much carbon was in it.
Now, the problem is your parents might not want you to be burning soil in the oven. So I'm not amending that, but you did ask that. Um, and then for the record, I have not done that. I sent soils off to the soil lab that does it for me. But, you know, the life and look for the color of the store. Um, but you want also, uh, be aware that different soils will form on different kinds of rocks.
Um, and so you'll often see that different kinds of plants will grow in different kinds of soils. Um, there's regions in California, where I grew up, where you can identify the local geology just by looking to see what plants are growing in the native plant communities on top of the land. Um, So it's, it's an N Soils are an interesting window into the world of biology.
Zanagee: Well, well, I'll have to go like outside of the chocolate cake and the soil outside,
Olivia: But don't eat it.
Dr. Montgomery: Don't eat it.
Zanagee: That’s a wrap on our conversation with Dr. David Montgomery about soil’s role in both contributing to AND solving the climate crisis. Which brings us to…that’s right folks…the
[CLIMATE JUSTICE GAME SHOW]
Olivia: Remember listeners, you can pause the show and say the answer to a friend, write it down on a piece of paper, or just think it in your head. And we will be playing right alongside you.
Zanagee: Okay Olivia: question 1: why is the ground beneath our feet so important when thinking about the impacts of climate change?
Olivia: Yes! Thanks for asking this question Zanagee. So many people know that plants and trees help take carbon dioxide out of the atmosphere. But less well known is that healthy soil can actually be a huge absorber of carbon dioxide. I didn’t know this until I was in college. Do you remember when you learned that healthy soil is important for balancing carbon dioxide in the atmosphere?
Zanagee: So actually, now that I think about it, I actually learned this late in high school in my senior year, learned about carbon sinks and how soils are so helpful with carbon and with bringing all that, that bad CO2 that's in the atmosphere from fossil fuels back down to earth. Uh, so that's when I learned, I also learned pretty late. So look at you all. You're all really early!
Olivia: Um, I feel like that is, um, that teacher deserves a shout out for, for teaching about this carbon sinks.
Zanagee: Yes. Shout out to Ms. Pegs, Ms. Pagliaro from my eyes. Cool.
Olivia: Awesome. Okay Zanagee, question 2: how do earthworms (and other microbes) contribute to the health of our soil and earth?
Zanagee: You know I love worms. So, worms and other microbes contribute to the health of our soil and earth because they ingest plant matter and through digestion merge mineral and organic matter to create fertilizer. Basically, worms and microbes keep our soil healthy, which allows it to absorb carbon dioxide and grow our food.
Olivia: Yes, it can be wild to think about how much we rely on things we can’t even see without a microscope.
Zanagee: Absolutely. Okay, third and final question: what information can we infer from the soil’s color?
Olivia: Oh, I loved what Dr. Montgomery taught us. Okay, so I remember Dr. Montgomery mentioning that light toned soils are generally less healthy than darker soils that look like chocolate cake. He even mentioned that scientific studies have documented that the carbon content of darker colored soils is higher than in lighter colored soils in the same region.
Zanagee: You got it. So next time you see some chocolate colored soil, you can take comfort in knowing that it’s taking some of our excess carbon dioxide out of our air and putting it back in the soil, where it belongs.
Olivia: Yes. So bonus question for you Zanagee, you might remember at the beginning, a song playing called Pebble Mine, and I'm wondering if you know what that song is in reference to?
Zanagee: I sure do what, let me tell you, so Pebble Mine, um, it would have been the largest mine in North America and it was a proposed project for Alaska. Um, and it would have mined different metals, like copper and gold and other metals that we need for things in Alaska. And it was threatening Bristle Bay, which is the body of water off the coast of Alaska. And it has one of the biggest populations of salmon. They've got bears, they've got all this incredible wildlife. And so environmental organizers organized against it for years. And they finally stopped it in 2020. And so pebble mine was a project that never was, and that was because of the movement.
Olivia: Wow. I did not know that. So 2020 that's really recent. Do you know when the organizing against Pebble Mine started?
Zanagee: I don't, but I know it was, uh, it predates my time in the movement actually. And it's incredible, but they stopped it because the Bristol bay watershed is one of the. Greatest, uh, ecosystems, um, in North America. So it's very exciting to see that that place will be saved.
Olivia: Oh, wow. Well, that is a good hopeful story and a great example of what persistence can do. And with that, that concludes today's episode of the climate justice game show. Thanks as always for playing and we will see you next time!
[CLOSING]
Olivia: Thank you, listeners, for joining us today. And thanks to Dr. Montgomery for sharing his expertise on soil health! You can find more about Dr. Montgomery’s work by visiting dig2grow.com– that's d-i-g the number “2” g-r-o-w .com– or by checking out his band, Big Dirt! We’ll also have a link in our show notes.
One Point Five is written by me, Olivia Greenspan
Zanagee: and me, Zanagee Artis.
Olivia: Our show is edited and produced by Cat Petru with help from Matthew Winner and the team at Sound On Studios. Our executive producer is Jelani Memory. And this show was brought to you by A Kids Podcast About.
Zanagee: This show is inspired by our book, A Kids Book About Climate Change, and the millions of young people around the world fighting for their right to a livable future.
Olivia: You can write to us at listen@akidspodcastabout.com. And check out other podcasts made for kids just like you by visiting akidsco.com.
We hope you enjoy this last song by Big Dirt called “Apologies Seven Generations in Advance”!