字幕表 動画を再生する 英語字幕をプリント This video is sponsored by Brilliant. When Alan Savory gave a TED talk in 2013, he captivated the world. Savory's speech cut right to the point: climate change, overpopulation, and desertification threatened to swallow the human world if left unchecked. But what delighted Savory's audience, as well as a number of the 4.3 million viewers on YouTube, was not this dire forecast, but rather Savory's solution to the problem: eat more meat and graze more cattle. That's right, Savory outlined a win-win scenario wherein if we just grazed more cattle in a very specific way, we could potentially turn back the tides of desertification, sequester carbon, and stop climate change. Which to me, in 2013 sounded great. Except, as I later learned, Allan Savory was wrong. This is the story of grassfed beef and rotational grazing. How it came to be this win-win solution to climate change, and how the hype around its implementation is, well, just plain wrong. Grass-fed beef will save the world? Savory is not alone on his quest to proselytize the good word of beef. Michael Pollen, in his book The Omnivore's Dilemma, gushes over Joel Salatin's intensive grazing techniques at Polyface farms, and even two years ago, I suggested in a video about going vegan, that rotational grazing systems had the potential to mitigate climate change. Of course, not all grass-fed beef is rotationally grazed beef, and indeed rotational grazing practices can vary from farm to farm. One rancher might only rotate their cows every 2 months, while another might rotate them every day. In general, grass-fed beef can be seen as an umbrella term for a variety of grazing systems, under which rotational or regenerative grazing operations are considered the gold standard and are lauded as possible climate saviours. The core belief behind all of these regenerative systems is that by constantly moving high numbers of cattle from one plot to the next, the cows will indiscriminately eat up plants--shocking them into growing deep roots. And when the plants eventually die, these roots will lock carbon into the ground. Regenerative grazing proponents also claim that livestock help sequester carbon with their manure, as well as by breaking up the soil crust with their hooves and burying carbon in the dirt where it is less prone to re-release. The result of all of this carbon sequestration, regenerative ranchers claim, is that these systems suck more greenhouse gases out of the air than cows emit through belching and manure. Essentially, regenerative grazing acts as a carbon sink that heals the soil and sucks greenhouse gases out of the air. And there have been a few studies that support this carbon sequestration hypothesis. In the Upper Midwest, one study found that high-rotation grazing did indeed store more carbon then the cows created. But here's the thing: these papers are outliers in a vast body of academic work on the subject. As we'll see soon, these claims are mostly unfounded, have better alternatives, and when they do work, often represent best-case scenarios with perfectly managed systems in the perfect setting. Why beef can't save the world: Despite Savory's beautiful pictures and convincing rhetoric of regrowth and grazing, his claims have been heavily criticized for a lack of scientific evidence. Keep in mind, this is the same man, who in 1969, argued for the massacred 40,000 elephants in Zimbabwe because he thought they were ruining their own habitat. Even Joel Salatin knows that his farm is not that sustainable: “Actually, everyone else calls us a sustainable farm. I don't call us a sustainable farm, because at the end of the day I really don't think we should be raising the number of broilers that we raise, for that very reason.” In a comprehensive analysis of the scientific research on rotational grazing, The Food Climate Research Network found that grazing systems only sequester around 20-60% of the emissions from livestock. In addition, grasslands can often reach a carbon storage equilibrium within a few decades. Which means that the soil's ability to sequester carbon slows over time and then eventually stops. Essentially, soils are not just some bottomless pit in which carbon can be endlessly stored. So, when the soil reaches that equilibrium point the cattle still grazing on the land will most definitely be creating a net addition to greenhouse gas emissions in the atmosphere. Research and conventional wisdom also shows that grass-fed beef requires more and older cows than feedlot finished beef. This is because grazed cows get a lot more exercise and fatten up much slower than their kin in feedlots. The end weights of grazed cows are generally lower, and the time it takes to get them to that weight is longer. All this means that cows have more time to emit greenhouse gases when grazed. And finally, regenerative grazing techniques require a lot of land. Right now, grazing-only ruminants contribute just 1g of protein per person per day in the global protein supply. And yet, despite contributing a negligible amount to the global protein mix, livestock grazing uses 26% of liveable land. Oh and beef production is the number-one driver of tropical deforestation in South America. So regenerative grazing, while good in theory, on the ground fails to live up to its hype. If scaled up, it would require massive tracts of land and could potentially create more emissions than it prevents. Indeed, in terms of the climate, it could be dangerous to pursue regenerative grazing, especially when there are perfectly sound alternatives that are known to sequester carbon and create far fewer emissions. What should we do? So if grass-fed beef and rotational grazing methods won't mitigate climate change, then what should we do? Let's consider what would happen if we didn't need grazing lands for livestock. We could instead implement reforestation, aforestation, and rewilding plans that over time could potentially lock up way more carbon than grazing systems. And vegetable-based farming systems like the no-till, compost-heavy operation at Singing Frogs farm in California, demonstrate that it's possible to sequester carbon without using cattle. But there are still over 200 million people who rely on grazing as a source of financial and nutritional stability. For them, a transition to rotational grazing systems must be a start, but a full transition away from a meat-based economy has to happen to dramatically reduce emissions, which means ranchers and cattle farmers across the world need ample support from governments to facilitate that transition. But, this would also be a transition for consumers. Cutting out meat is one of the most effective and achievable personal solutions to climate change. Project Drawdown models that if 50% of the world adopted plant-rich diets we'd be able to avoid 65.02 gigatons of carbon dioxide-equivalent gases by 2050, which is about the same impact that removing every single form of transportation from the earth for nine years would have. But Americans in particular eat a lot of meat, and it's challenging to stop buying animal products in a world where a full meat-based meal is often cheaper and easier to access than produce or meat alternatives. Which means that government must also subsidize and promoting the practices of operations like Singing Frogs Farm or vegetable farms in neighborhoods experiencing food apartheid. Because, at the end of the day, fostering food systems that create access to nutritious and pleasurable plant-based food means fostering food systems that protect the climate. This video took a while to research because there's so much out there on grazed beef. But honestly, that's one of my favorite parts of the creation process. I love diving into educational content, which is why I'm constantly recommending Brilliant. It's a website and app that uses problem-solving and active learning to make learning accessible and fun. Brilliant is all about seeing concepts visually and interacting with them, and then answering questions that get you to think. Their courses are laid out like a story, and broken down into awesome visual pieces so that you can tackle them a little bit at a time. Take, for example, Brilliant's completely revamped course on the fundamentals of Geometry. I was terrible at Geometry in school, but Brilliant laid out the ideas behind angles, perimeters, and coordinates in such an intuitive way that it made Geometry actually kind of fun to learn. This little interactive triangle is a perfect example. By changing the side lengths, we can easily see that the sum of the triangle's internal angles is always 180. But Charlie, what if I get something wrong? Well, with Brilliant, there's no tests and no grades — if you make a mistake, no big deal. You can just check out the handy explanations to find out why you messed up, which for me, happens often. You can learn at your own pace, and there's something for everybody — whether you want to brush up on the basics of algebra, learn programming, or learn about cutting-edge topics like Neural Networks. So, if you're curious like me and want to learn something new, then go to brilliant dot org slash OCC, or click the link in the description, and sign up for free. As a bonus, the first 200 people that go to that link will get 20% off their annual premium membership. Hey everyone, Charlie here. This video, as always, was made possible by my patreon supporters. They donate a couple of dollars each month to help me grow and build this channel so it can reach an even bigger audience. Thank you so much to my patreon supporters and thank you for watching! I'll see you in two weeks!