 How can growing food at home help fight carbon emissions, which plants are best for reducing our use of fossil fuels? And how does this help us think about a future of local food? Let's get into it. This is the Low Tech Podcast. Hello and welcome. I'm Scott Johnson from the Low Technology Institute. You're host for podcast number 67 on March 10, 2023, coming to you from the Low Tech Recording booth. Thanks for joining us today. We're talking carbon emissions, what we eat, and how they're linked. Don't forget to follow us on Twitter. Our handle is at low underscore techno. Like us on Facebook, find us on Instagram, subscribe to us on YouTube, and check out our website lowtechinstitute.org. There you can buy both of our podcasts as well as information about joining and supporting the Institute and its research. Also, some podcast distributors put ads on podcasts. Unless you hear me doing the ad, someone else is making money on that advertising. While all of our podcast videos and other information are given freely, they do take resources to make. And if you're in a position to help support our work and be part of this community, please consider becoming a monthly supporter for as little as $3 a month through our Patreon page patreon.com slash lowtechinstitute. Thanks to Math H for recently signing up. Another way to support us is to donate your used car. Anyone in the US can contact us and your used car will be picked up, sold, and the proceeds come our way. If you're interested in helping us out this way, get in touch with us, set info at lowtechinstitute.org. If you'd like to sponsor an episode directly, please get in touch with us through our website lowtechinstitute.org. Okay, today, we're going to be talking about carbon emissions, growing food, and how that works into the future. And the reason that I focus on carbon emissions is because it's kind of a shorthand for the use of fossil fuels in our food system. And as you'll see, there's a shocking amount of fossil fuels used for our everyday food that we buy at the grocery store or basically most of us, the way we get our food is very deeply tied to the use of fossil fuels. And in the future, we're going to have to convert our entire food system to run without fossil fuels. And so by pinpointing those foods that are a middle out of carbon, we're pinpointing foods that are going to have trouble or need to change the most in a less carbon intensive future. And what we advocate for here at the Low Technology Institute, of course, is locally grown food as well as other things, but really centering our lives, at least the subsistence of our lives locally. So let's get into carbon gardening. So before we get into actual gardening, let's talk a little bit about carbon emissions. And I'm basing a lot of this on a pretty entry level book called How Bad Are Bananas, which is a fun kind of look at the carbon footprint of everything, as it claims, by Mike Berners-Lee. I'll link to it in the show notes. And it's kind of an easy introduction to get you thinking about the carbon emissions of all kinds of things in our everyday lives. And again, I mentioned carbon emissions as kind of a shorthand or an equivalent to fossil fuel use. The more carbon emissions, the more fossil fuels are likely going into that. And so we hear the term carbon footprint all the time, but often I feel like people have a pretty ephemeral understanding of what that is. So carbon footprint is just the net impact that something has on global greenhouse gas levels. And this is often expressed as CO2 equivalents. So if I say CO2, here I'm largely just referring to CO2 equivalents, which is a kind of way to flatten, but all the different greenhouse gases into one measurement. So carbon dioxide equivalents are used just as a shorthand. For example, methane, CH4, is 25 times more potent than CO2 alone. So instead of saying it emits this much carbon dioxide and this much methane, and then you'd have to convert the methane to figure out how bad that actually is, we just say CO2 equivalents. Nitrous oxide, another greenhouse gas, N2O, emit 300 times more potent than the equivalent of CO2. So we just kind of flatten all of that into CO2 equivalents. And I'm just say CO2 for shorthand because it's shorter for the purposes of this podcast. So when you hear people talking about the carbon dioxide emissions or the greenhouse gas emissions, that's kind of what they're talking about, how much of these different greenhouse gases are emitted for different activities. For example, I was just looking at flights, I know flights to Philadelphia for an upcoming event that I need to get to, and time is short. And so instead of the train, I'm going to have to fly. And right there next to the cost of the flight was the CO2 that was going to be generated or the CO2 equivalents. And one thing when we're talking about CO2 is that we want to be careful of what's called the carbon tow print. And this is when we're looking very superficially at the emissions of a product. For example, if I think, well, how much is the carbon footprint of buying an apple? And I drive to the store, buy an apple and drive home. And then I just calculate the CO2 of me driving to the store. That's only the tow print or one small part of the CO2 required to produce that apple. And so really what we have to do is look at the entire supply chain from start to finish. And that becomes very quickly complicated, as you can imagine. For example, with any type of agriculture that uses a tractor, right, if I'm eating a carrot, and that was harvested by something pulled behind a tractor, how much of the carbon emissions of the production of that tractor should be attributed to that one carrot? How much of the carbon footprint of the factory that builds that tractor should be then, you know, carried over to the carrot? It's kind of like pulling the thread on a sweater. We go, it's all interconnected. So we have to draw the line somewhere. And for the most part, a CO2 equivalence or the CO2 emissions of any particular product I'm going to talk about or any particular plant, you have to take it with a grain of salt. It's an approximation. One thing we can do is look at per capita emissions, how much people in different countries on average emit. And that's by taking the sum of all carbon emissions of that entire country, dividing it by the population of that country for a year. And for example, the average American burns 16.5 tons or emits 16.5 carbon dioxide emissions total per day. The global average is only four. So what does 16.5 tons of carbon emissions look like? That would be about 33 barrels of oil, 55 gallon barrels of oil set on fire every day. Let me repeat that. The average American emits as much as 33 55 gallon drums of oil or of gasoline set on fire and let to burn. Just imagine that 33 barrels of gasoline burning, right? Just sitting out in your backyard every day. That's how much carbon the average American is putting out. And you might say, well, I drive a Tesla, I have all these different things that I do to reduce my carbon footprint. And that very well may be true. And your number might be slightly less than that. And that's wonderful. But remember, this has to, if you think about the entire network that supports your life, you have to count those too, right? So getting your trash picked up, right? That counts towards your CO2 emissions. And so there's different things that we can't really get away from. They're baked into how our lives are set up. The average global citizen is closer to four tons. That's eight 55 gallon drums of gasoline set on fire every day. And this is all from the World Bank data, about a fifth of those carbon emissions are attributed to food, about 3.3 tons of CO2 emissions for meat lovers per day. If you're vegetarian, it's somewhere about half that 1.7 to 1.5. That's why a lot of environmentalists are so keen on people becoming vegetarians. It's although many people also have a problem with the cruelty to animals and the way that industrial agriculture treats animals, which right, that's a that's a moral argument for sure. But just on the carbon emissions alone, it's half as carbon intensive to be a vegetarian. And the reason for that is it takes about seven calories of plant food to make one calorie of meat. So for every calorie of meat you eat, you're emitting enough for seven calories of plants. And so it's quite quite a lot of energy stored into that meat. And so by changing to a vegetarian lifestyle or switching over to eat less meat in general, that can really reduce carbon footprint. And for us, for example, you know, we hunt venison and butcher our own chickens. And so our meat intake is significantly less. But for example, we do about once a week, we eat meat. And so our carbon footprint is significantly reduced by by doing that. Alright, so let's move on and talk about a few examples of carbon emissions for food. And we're going to go through ranges here because it's not cut and dried. I can't just say, well, an apple has x grams of carbon dioxide equivalent emissions, because not all apples are the same. Let's start with an apple. An apple, if you pick it in your backyard from your own tree, and you're going to see this as a trend, if you grow it and pick it yourself, you are pretty much dealing with no emissions, maybe even negative emissions. If you plant an apple tree, and fertilize it with your own compost, and keep everything on site, that tree is sucking carbon out of the atmosphere. And now people like to say, well, trees are great for sucking carbon out of the atmosphere. And that's true while they're alive. But once they die, and they start to compost and decompose, they release that CO2 back in the atmosphere, unless those trees get cut down and buried, and that carbon is truly sequestered, that is part of the carbon cycle, it isn't truly fully sequestering the carbon. Now if we have more trees growing at any one point in time, that will sequester carbon. But planting one tree and then letting it fall down and rot is not saving carbon. I hear that all the time. So I hear about how important trees are, and they are obviously important. And the total number of trees growing does reduce carbon emissions. But one specific tree isn't, so you can already see how complicated it gets to track down the CO2 of a particular item that you're eating. If you pick up local apples, let's say you drive out to a local orchard and get apples, you can count on about 10 grams of CO2 equivalents per apple. If you buy them at the grocery store, each apple is about 80 grams of CO2 equivalents. And if you get those apples shipped, their specialty, they're kept cool and refrigerated and all this, you could be using up to 150 grams of CO2 equivalents per apple. What does that mean? What's 150 grams of CO2? That would be something like ironing for an hour or watching TV for an hour that be closer to 80. Using your cell phone is actually really pretty low compared to like a computer. That would be something more like a 10 grams per hour. So apples are kind of in the range of TV watching ironing down to cell phone use in terms of carbon emissions, just to kind of give you an equivalent idea. The key to keeping the carbon emissions low for an apple, and again, these are just examples, we'll talk specifically about what you should grow or what you could consider growing to reduce your own carbon emissions in a bit. Keys are, and we'll see these over and over, apples often don't have packaging. They are able to be shipped slowly and they're grown out in the open rather than say a hot house. What about a banana? These must have a lot of carbon emissions, right? They're a tropical fruit. Well, if you grow your own banana, again, zero grams of carbon, if you buy one at the store, they're actually only about 80 grams of carbon per banana. And the reason is because they're cut green, and then they're shipped in boats, which is slow. They also don't have much for packaging. And this allows them to be a fairly surprisingly low carbon fruit and orange. Again, you pick it yourself from your own property. That's about zero grams. But if you buy it at the grocery store, and it's been say shipped 2,000 miles by boat and then another 500 miles by truck, you're looking at about 90 grams of CO2 equivalents per orange. If though, that's an air freighted orange, and it like when I lived up in Northern Alberta, I imagine those oranges were flown in and they were very expensive. And that's a whole kilo or a thousand grams of CO2 equivalents when it's in the off season and freighted in. The key to having low carbon emissions for an orange is the long shelf life, allowing slow shipping and growing them outside. What about something a little more intensive, a basket of strawberries? Again, ours in our backyard, probably zero grams of carbon dioxide equivalents. If they're regionally grown, so I go to the farmers market, I pick some up, that's about 150 grams for a basket. If right now it's March, they're being flown in probably from Mexico or other places, that's 1.8 kilograms, 1.8 kilograms 10 times as much as when you get them at the farmers market of CO2. The reason for that is they have a relatively short self-life and they are best enjoyed seasonally or preserved. That fast shipping is a real CO2 emitter. What about a kilo of carrots? So 2.2 pounds is a kilo. What about a kilo of carrots in your own garden? Again, zero grams. If you buy them locally in seasons at the farmers market, you're looking at about 250 grams of CO2 equivalents. If you get them at the grocery store, that's really only 300 grams, so not so bad. But if you buy baby carrots, they are four times more emittive. So one kilo of carbon emissions for one kilo of carrots. And the reason for that is babies are much less efficient. They must be kept cooler. They have more production cost or work and they have to be shipped very quickly. Whereas normally, and this is true for a lot of root vegetables, they're great. They store well, they can be shipped slow, they don't need a lot of packaging. So relatively speaking, root vegetables are actually pretty good for carbon emission other than baby carrots, as I mentioned. Case in point, a kilo of potatoes. Grown in your garden, again, zero grams. Get them from the grocer. You're looking at about 370 grams carbon per kilo. Again, the key for potatoes is they store well. They're a root vegetable. You can ship them slowly. They don't need refrigeration. All of these are points in their favor. On the opposite end of the spectrum, let's look at just a half a pound of asparagus, a half a pound. Grown in your garden, zero grams. Get them locally from the farmer's market, about 125 grams of CO2 equivalents. But if you buy them right now, March, out of season, flown in from say South America, you're looking at a whopping 1.9 kilograms of carbon emissions for that half pound of asparagus. The takeaway for asparagus is fine as a seasonal treat, but it's really pretty bad outside of the season. What about some staples? Let's look at a kilo of wheat. A kilo of wheat emits about 1.8 kilograms of CO2 emissions, equivalents per kilo. The nice thing about wheat is it stores well. It doesn't need refrigeration, but the downside is it needs a lot of industrial production to get that kilo of wheat. Compare that again back to another staple like potatoes, which need a lot less processing. They're much lower per pound in CO2 emissions. What about rice? Rice is a really interesting one. So a kilo of rice actually emits 2.5 kilogram equivalents of carbon dioxide, if efficiently grown. On average though, it's about 4 kilos of CO2 emissions per kilo of rice. And if it's inefficiently grown, it's 6.1 kilograms of CO2 per kilo. So that's way worse than wheat. It's almost three or four times more carbon intensive. And the reason for that is rice is grown in patties. Patties are kind of stagnant water, and that produces a lot of methane. It also uses a lot of fertilizer. So rice on the production side produces quite a lot of CO2, but otherwise it's pretty good because like wheat, it dries and stores without refrigeration and ships really slowly. So that really cuts down on the carbon from that end of things. Finally, last example, a kilo of tomatoes. Again, growing tomatoes in your garden, zero grams. 400 grams though of carbon dioxide equivalents. If you're buying organic in season local, say again from the farmer's market, so that's about 400 grams per kilo. If though you're buying from the grocery store, just an average tomato from the grocery store, you're looking at 9.1 kilos of CO2 equivalents per kilo of tomatoes. Let me say that again, 9 times the amount of CO2 than the weight of the product. So for each kilo of tomatoes, you're looking at over 9 kilos of carbon dioxide equivalents. If even worse, let's say it's March and you're in Northern Alberta like I used to live and you're buying on-the-vine cherry tomatoes, you're looking at a whopping 50 kilograms of CO2 equivalents for your kilo of tomatoes because they have to be grown. That's the worst case scenario because specialty varieties are lower yielding than non-specialty varieties. It's being grown in the off season means it has to be grown in a hot house and it has to be transported quickly and they don't transport well because they're a soft fruit. So if you avoid those things, if you buy tomatoes in season at the farmer's market or grow them in your garden, they're great. But if you're buying them at the grocery store, especially out of season, they are really, really carbon intensive and we do see that somewhat in the cost of food, right? We do price this in and you can tell that like asparagus and tomatoes and other things in the winter are much more expensive. So the takeaways, these are the four main takeaways to avoid carbon emissions in your food. Avoid things that are fresh, fragile, far away or off season. And I wish I could have gotten off season to start with an F somehow. If you can think of a way to say off season with an F word starting it out, that'd be great because then I'd have fresh, fragile, far away, off season, right? Off season, I guess off has two Fs. But those four things help us kind of encompass everything we've talked about so far with the examples of carbon intensive foods. So when we're talking about fresh things, we're talking like lettuce and other things that have to be transported really quickly, fragile, things like eggs, tomatoes, other fruits and vegetables that bruise easily, things that are far away. Obviously they have to be shipped faster on things like planes that really ups the carbon emissions and then off season they have to be shipped far, they have to be grown in adverse conditions, all of that takes energy. And again, the carbon emissions remember is just a shorthand for the use of fossil fuels at least right now. And so by focusing on reducing the carbon emissions, we're also reducing our dependence and use of fossil fuels in our food system, which is really important. There's a really interesting study in Switzerland. So it's slightly different for us because we have access to California, Switzerland, largely gets a lot of its off season produce from Spain. So it's kind of equivalent there. And they looked at what were the biggest carbon emitters. And so for concrete examples of things, especially off season to avoid are things like asparagus, lettuce, bananas, tomatoes, pears, and then going down the list, more citrus, cucumber, apple, vine, tomatoes, grapes, things like that. And then you start to get into things that are a little better. If you're buying them at the store, things like bell peppers, potatoes, avocado, melon, kiwi, strawberry, again, when they're on season, leeks, onions, carrots, cauliflower, pineapple, broccoli, eggplant, and other things like that, which ship a little better and a little slower. It depends what you can grow where you are. We're in Wisconsin. So I'm going to be couching a lot of what I talk about for growing in Wisconsin, in Wisconsin's temperatures. But generally speaking, if you want to reduce your dependence on fossil fuels, and we're talking about it in the guise of carbon emissions today, you can do that by growing the things that have higher carbon footprints when you buy them at the store. So if you really like asparagus, lettuce, cucumbers, things like that, you'd be better off growing them yourself, preferably, or buying them at least at the farmer's market. And so when I run down that list starting with asparagus, lettuce, banana, tomato, pear, et cetera, the more you can buy locally, that's really going to make a big difference. And you're going to have to buy more seasonally, because where you are is going to dictate what things are available when. And that's why things like jams and preserves and canning is so, used to be so popular. Things come cyclically in the year. You plant them, grow them, harvest them, preserve them. And that way you can enjoy them throughout more of the year without increasing your carbon footprint. We don't have to have fresh tomatoes to have chili. Crushed tomatoes in a can are perfectly good. So some other things to do when you're planning your garden, if this is something you want to think about, you really want to pick the things you like to eat, because we'll talk a little bit about food waste and other things, but really think about what types of food you like to eat, which ones have the most carbon intensive production, and then focus on those if this is if this is your goal. So let's talk about other ways to reduce our food impact or our carbon emissions. Number one, don't be so picky. If you're growing your own food, you'll be surprised at the variety of fruits and vegetables that come out and how they look because at the grocery store, they have sorted and you're only buying the best looking produce. The non-great looking produce goes into things like V8, right? You can get a tomato or a carrot or other vegetable that doesn't look great, but is perfectly healthy and sound. They'll grind it up and put it into juices or they'll can it into tomato soup or they'll do some other thing with it rather than try and sell you something that doesn't look great. And I have seen recently on social media ads for things called, I don't know exactly what they're called, but basically it's a box of seconds of fruits and vegetables that don't look ugly produce or something like that. It's called and it's kind of a shame to see these on social media because basically what's happened is there used to be this secondary stream of unsalable fruits and vegetables that are perfectly healthy and perfectly safe to eat, but they just don't look as nice as the producers want and they used to donate these to food banks, but now they realized, hey, we can sell these as quote unquote ugly foods and actually make money on them instead of donating them, which is kind of a bummer. So when you are growing your own food or growing your own stuff in the garden, give yourself some slack. Not everything's going to look great. A lot of it's going to taste great because it's grown locally. You can allow it to ripen fully rather than being artificially ripened like most tomatoes are, for example, but give yourself some slack. Things are going to look different. If it doesn't look great visually and that bothers you, can it or make something else and make a stew or a soup, right? A 10th of fresh produce is tossed out because it's unsalable but still edible. If you don't have space to garden, one thing you could do is go to the grocery store and see about what's on sale, what's about to go off, what are they getting rid of? And if you make a good relationship with your grocer, sometimes they'll set things aside for you. And then you can can those things. I used to go to the farmer's market at the end of the day to see what I could get deals on. And often I would go home with grocery bags just full of produce and then I would can them and preserve them because they were about to go off. The farmer didn't want to take them home so they made me a deal. That's another way you can do it. Another thing you can do right now in your own home is not waste food. A third of produce and food is wasted at home because it goes bad. And so there's a couple of different ways that you can do that. And this is a point of contention in our own household but get a smaller fridge because it's harder to hide bad food if you have a smaller fridge. Shop smart so when you go to the grocery store make sure you're not over buying or under buying especially produce and things that need to be eaten within a short time frame. Again buy ugly produce. Look for the stuff that's about to go off. Potentially can that or preserve it somehow. Save your leftovers or feed them to your chickens or something like that. Right and make sure you eat them instead of letting them go bad. Take smaller portions and take you know seconds rather than one big portion and then scrape your plate off. Donate excess food so at least there's somebody out there that is hungry that will take that food. Food banks and other things. My neighbor is a retired market gardener and he largely grows four food banks now and organize your fridge. So what we do and I'm not saying everyone has to do this but what we do the top shelf is things that are long term like jellies, jams and things that won't go bad being left in the fridge for a little longer. That's on the top shelf and then we have a cheese drawer and then we have a shelf of short term stuff stuff that needs to be eaten soon and that's the most visible shelf and that way we try and avoid having our stuff go bad. And then finally compost and the reason compost is important well there's a number of reasons. First we want to preserve that nitrogen. We spend a lot of fossil fuels to make nitrogen to turn into foods and when we throw that away we are basically wasting that nitrogen that could be used to grow more food. So composting preserves that nitrogen number one. Number two when you compost properly you're not emitting as much carbon dioxide equivalents or namely methane then when you throw food away. When you throw food away it goes to a landfill where it gets crushed under a whole bunch of other garbage and then it produces a lot of methane through anaerobic digestion meaning there's a lack of oxygen and the bacteria that thrive at that point to eat organic material produce methane which is a lot more carbon a lot more potent than carbon dioxide and therefore if you compost properly in your backyard and you turn it often and it's hot and well-functioning compost pile you're only emitting carbon dioxide instead of methane so that's a benefit also. So in summation try and get your food fresh and local as much as you can in season and avoid the fresh fragile far away off season foods and that's going to do a lot to reduce your carbon footprint for your vegetables and fruits. Obviously growing those more carbon intensive fruits that you would otherwise get at the grocery store is going to be your best bet for saving or reducing your carbon footprint and then on the backside or on the use side use those ugly fruit produce use composting to help sequester and maintain that nitrogen and don't let food go to waste. So those are a lot of the things you can do to reduce your carbon footprint and overall reduce your dependence on fossil fuels for your own food. I want to take a quick second as we wrap up here to talk about some classes we have coming up at the Institute. In the next few weeks we have a number of timber frame related classes that I hope some of you might be interested in taking. On March 25th we're going to be building a toolbox for timber framing tools at Grand Inspired in Stoton. On March 26th that's the next day we're going to be felling trees with an eye to cutting them up for timber. On April 1st we'll be refurbishing antique timber frame tools and other tools if you're interested in that and on April 8th we're going to be building mallets and potentially saw horses for use in timber framing. So those are some classes that we have on our website lowtechinstitute.org slash events. So check those out you can sign up for some of them already and you can look for the rest of the summer we're going to have a lot of cool classes we're going to be milling timbers we'll teach people how to cut down tree into a usable timber for framing or boards for lumber we're going to be building a stone foundation we'll be cutting timber framing joints assembling the floor and the main structure we'll be adding a roof putting on siding floorboards and we'll be filling the walls with light straw clay infill building windows doing lime plaster floor our interiors all kinds of great stuff electrical plumbing heating throughout the entire summer so if you are interested in learning about more locally built structures this might be a fun series of workshops for you also keep an eye out our website and our blog for upcoming announcements for other classes like we'll probably do our annual apple grafting and pruning class this spring in April so keep an eye out for that if you want to be the first to know about these classes become a member members get emails letting you know when classes are available for signing up as well as a discount and you can also sign up for free to our listserv just go to our website scroll down to the bottom and there you can find out how to sign up for our listserv to make sure that you are kept up to date on all the classes we have coming out in the near future that's it for this week the low-tech podcast is put out by the low technology institute the show is hosted and co-produced by me scott johnson and co-produced and edited by hina sezuki this episode was recorded in the low-tech recording room subscribe to the podcast on itunes spotify google play youtube and elsewhere we hope you enjoyed this free podcast and if you'd like to join the community and help support the work we do please consider going to patreon.com slash low tech institute and signing up thanks to our forester and land steward level members sam brawn maryland scarpon and the havestes for their support the low technology institute is a 501c3 research organization supported by members grants and underwriting you can find out more information about the low technology institute membership and underwriting at lowtech institute.org find us on social media and reach me directly scott at lowtech institute.org our entry music was Saturn off the album interstellar pop songs by halizna that song is under the creative commons universal license and this podcast is under the creative commons attribution and share like license meaning you're free to use and share it as long as you give us credit thanks and take care