- Ami Eckard-Lee: You know what's cool about trees? They breathe in what we breathe out, and we breathe in what they breathe out. It's a cycle. Part of the carbon cycle, to be exact. But there's so much more to the carbon cycle than just people, plants, and animals. The Sun plays a role, the ocean is involved, and the soil beneath your feet is a huge factor. The carbon cycle affects the atmosphere, the weather, and the climate. When the carbon cycle is balanced, ecosystems run smoothly. But how does an imbalanced carbon cycle impact the environment? [bright music] Ecosystems function almost like a machine. Everything has its role, and if something deviates from its role, the whole system is impacted. Maybe that's why it's called an eco-system. Let's meet up with an ecosystem scientist to learn more about carbon's role in an ecosystem. So, when did carbon start to become, like, a problem? 
- Nate Lawrence: It was about the Industrial Revolution. Whenever a whole lot of carbon that had been built up in fossil fuels over millions of years started to be burned to fuel society. So, we started burning things like coal and oil and natural gas. And when we do that, we're releasing a whole lot of carbon that's been stored for millions of years into the atmosphere all at once. And that big pulse of carbon is the primary driver of climate change today. So, now, when we think about what's driving the increase in carbon dioxide in the atmosphere, a source of carbon dioxide would be something that's causing the amount of carbon dioxide in the atmosphere to go up. 
- Okay. 
- So, for example, burning those fossil fuels. A carbon sink would be something like a growing plant. So, as the plant is growing, it's sequestering carbon that used to be in the atmosphere and is now, for the time being, tied up in that plant. So, a sink is drawing carbon down. A source is putting carbon up. 
- A carbon sink is a large reservoir that absorbs more carbon from the atmosphere than it releases. Some examples of carbon sinks are oceans, forests, and soils. CO2 dissolves directly into seawater, and ocean currents distribute it and store it in deeper waters. Forests absorb carbon from the atmosphere through photosynthesis. The trees then use this carbon to grow, so it's stored in the trunk, branches, leaves, and roots. And forests help store carbon in the soils too. Carbon is released into the soil through plant roots, where it's then stored. Another way carbon enters the soil is through the decomposition of organic matter, such as plants and animals. These carbon sinks work together to absorb carbon from the atmosphere and store it. But what happens when one carbon sink is storing too much, and another isn't storing enough? 
- We've been a big driver of release of carbon from these long-term pools through human activities. We cut down a lot of trees, we disturb a lot of soil. So, the oceans are taking up a lot of excess carbon dioxide from the atmosphere, which is good. It means it's not in the atmosphere causing climate change, but it also leads to more acidic seawater, threatening a lot of ocean life. 
- Human practices have had a major impact on the carbon cycle due to excessive carbon emissions, making the cycle unbalanced. Now, there's too much carbon in the atmosphere and in our oceans, but not enough carbon being stored in other sinks, like forests and soils. So, what can we do to help rebalance the carbon cycle? 
- So, there's an ecological principle that says that the more diverse our ecosystems are, they should be more effective at capturing energy from the Sun, and thereby pull some of that carbon dioxide out of the atmosphere and help mitigate some of the impacts of climate change. 
- Okay. 
- So, behind us, we see one example of what that can look like. This is a silvopasture. It's grazed by sheep. 
- Ami: What's silvopasture? 
- Nate: Silvo, Latin for tree. So, silvopasture is a tree pasture. The trees are chestnuts, so the trees both produce something that we can eat, and they also provide shade for the sheep. We can't change what has happened in the last 150 years. So, now, we're hoping to implement different types of ag practices, produce our food a little bit differently, and if we get it right, the soil health that we've lost, we can actually start to regain. 
- Let's talk to Daniel Hayden, a citizen of the Comanche Nation, who can tell us about Indigenous farming practices that have been climate smart and sustainable for generations. Hey, Daniel! I have so many questions for you. What's the biggest difference between Indigenous farming practices and modern farming practices? 
- Daniel Hayden: So, Indigenous farming practices in North America were very different from our modern Western agricultural systems, predominantly because of the lack of tillage. Practices like tillage are very destructive and degrading to the environment long term. There's so much that time and history has gone into the creation of soil. And we've seen such a rapid degradation of that through farming practices. What makes Indigenous farming practices more sustainable, I think, is the legacy of how Indigenous people were listening to the land. A lot of Indigenous culture is based in land and in the environment. 
- What's an example of an Indigenous farming practice? 
- The Three Sisters has been this genius idea that, you know, developed for centuries through time and, you know, still practiced now, obviously. 
- Wait, wait, what are the Three Sisters? 
- Daniel: Corn, beans, and squash. So, the Three Sisters specifically were grown together on a mound of soil. Each crop sort of plays their own functional purpose. So, corn grows really tall. And because of that, beans, the other sister, are able to grow up the corn and also below ground. They're adding soil nutrients. Squash, the big leaves of the squash typically are nice for shading out weeds. Practices like the Three Sisters, for example, have been shown to be more productive in some cases than just growing corn, beans, and squash by themselves. These resilient systems are ones that can maintain themselves while being adaptive to things like climate change. 
- By adapting our farming practices to work with the landscape, rather than attempting to alter the landscape, we can cultivate environments that are beneficial to the crops, soil, and people. So, can you tell me what kind of farm do you work on here? 
- Rylee Nelson: It's a grass-fed beef farm. So, we raise our grass-fed beef herd here through rotational grazing. And then, we also have some sheep that we raise alongside them. 
- You talked about rotational grazing. What does that actually mean? 
- Rylee: We move the cattle every single day in the summer. We use a polywire in a reel to move them, so they'll get a new area of pasture each day. So, we need that soil to be healthy because it builds up the diversity of our plants and makes sure that our cattle are getting all their needed nutrients from our pastures. We need to do our job as not only producers, but consumers as well, to maintain that healthy soil and continue to improve it. 
- How can you tell the difference between healthy and unhealthy soil? 
- So, our soil is healthy, and I can tell that because there's no erosion. If you look at the soil, there's a lot of organic matter on the top, which shows us that their manure and everything is going back into the soil and it's not running off into our waterways. Also, we can see lots of different variety of grasses, which is important to us, and that shows us that there is different root structures in the grass. On our farm, there's always something in the soil which is holding that soil down and keeping that root structure in the ground, which is gonna really sequester that carbon and hold in those nutrients that are otherwise getting lost on these other farms. And that would be really helpful to building up our soil health. [cattle lowing] - They agree. 
- Yeah! [both laughing] - Improving the health of our soils can seem like a daunting task. I mean, we're literally talking about changing the ground beneath our feet. But there are so many ways for us to get involved in protecting soils. A great place to start is by looking at the foods you eat and knowing where they came from. Support farms that are using sustainable practices like agroforestry, rotational grazing, and organic methods. If you want a more direct approach, you can plant your own carbon-sequestering plants at home or in your community. If you have a garden plot, try planting crops that maintain their root system and will grow back next year, and try companion planting for a bountiful harvest that's good for the soil. All of these are great ways to contribute to improving soil health in your community. So, now, each time you prepare your dinner plate or relax under the shade of a tree, you know that you helped store more carbon in the soil where it belongs. Oh, hi, there. That's how it felt. [all laughing] I really can't do that, okay? 
- Producer: It's like aFull House-- - Oh, I didn't see you there! [laughing] Is that the end?