Meat And Food Waste Drive Farming's Huge Climate Toll

DRAWDOWN — 100 Ways to Reverse Global Warming

“Drawdown” is a project-style book led by an American writer, with contributions from researchers around the world. It lays out what can be done to bring about “drawdown — the point at which carbon dioxide levels start to decline,” split broadly into two parts: a survey of what is currently being done, and an introduction to future technologies. The “current state of understanding” section in particular was shocking to me personally, since there were many items I didn’t know the details of, or wasn’t even aware of at all. I’d call it required reading for working adults. But at over 400 pages in two-column format, the book is easily the equivalent of three ordinary books, and even for me, a fairly fast reader, it took over a month to finish.

Here I want to extract and organize the essence of it to some degree. In any case, this is a book perfectly suited to grasping the “big picture.”

About the agriculture sector

Personally, I was struck by the enormous potential in the agriculture sector — how much still isn’t being done that should be.

Meat

Livestock-derived greenhouse gas emissions rank second after fossil fuels, and once you add deforestation and food waste, livestock becomes number one. It’s become widely known in recent years that ruminants produce methane, but especially in the US, this is propped up by enormous livestock subsidies. Without them, meat would have been an “occasional treat.” Today, the average person in North America is said to consume 90g of protein per day (the healthy guideline is 50g).

Food Waste

Food waste amounts to a third of production. Despite this, 800 million people are in a state of hunger. Food production naturally involves fossil fuel use and CO2-emitting processes, and a third of that is wasted. Measured against national emissions, this waste is exceeded only by the US and China. Nitrogen fertilizer, for example, becomes a source of nitrous oxide. Fully 1.2% of total global energy use goes into producing nitrogen fertilizer, but most of it remains in the atmosphere as the greenhouse gas nitrous oxide. Or it runs off into the ocean, triggering algal blooms, oxygen depletion, and mass fish die-offs. In low-income countries, unintended waste from underdeveloped supply chains is the main cause. In high-income countries, the waste is intended — avoidable.

Multistrata Agroforestry

Layering multiple crops and plantings increases water retention and raises the efficiency of carbon storage. It also yields food as a bonus. Coffee, for example, is naturally grown in the shade, which produces the best quality. Growing it in full sun yields more, but dramatically degrades the soil. Mixed into a multistrata farming system, though, coffee can achieve a certain degree of permanence. A home vegetable garden can be called a longstanding form of multistrata agroforestry. It makes you realize that you can feed yourself somehow, as long as there’s sunlight, without needing the outstanding knowledge or skill of an expert. Nuclear power and ethanol are not solutions — they only create new problems. Multistrata agroforestry requires land with high moisture, involves high upfront costs since mechanization is difficult, and takes a long time to pay back — it loses out to other farming methods in terms of immediate yield. But once established, it withstands weather variability, curbs deforestation effectively, captures carbon at a high rate, and can produce 1 calorie of nutrition using just 0.02 calories of energy — a level of performance that stands far above the rest. It’s said that “agriculture depends on cheap energy.” Indeed, there are cases where 10 calories of fossil fuel go into producing 1 calorie of food, simply because that makes more economic sense — the energy balance doesn’t add up, but the economic balance does.

Zaï Farming

Farmers in Burkina Faso arrived at agroforestry on their own. By digging larger holes and adding compost, they increased not only yields but also the number of trees. Fallen leaves serve as mulch, a covering that helps retain moisture. Trees come to be seen as assets rather than weeds, and are sometimes sold. The more trees there are, the richer the land becomes, providing feed for livestock and habitat for wildlife. Burkina Faso has a history of Europe repeatedly and capriciously introducing the latest farming methods, but in the end these methods failed, and the local residents’ own approach was proven right. Agroforestry has also become commonplace in places like Mali and Niger.

Regenerative Agriculture and Conservation Agriculture

The basic concept is similar, and in Japan it’s called “natural farming.” When it restores abandoned land, it’s called regenerative agriculture. No tilling. Before the 18th century, fields were mostly not tilled. No-till farming methods emerged in the 1970s. Tilling releases methane from the soil and leaves the land unable to retain carbon. When carbon is absorbed into the soil, microorganisms increase and soil quality improves. Earthworms dig holes, which increases nutrient uptake and water retention. The idea is that well-nourished plants become more resistant to pests, so fertilizer becomes unnecessary. Still, seeds are sown without tilling, and harvest residue is either left in place or a cover crop is planted there. The cover crop blocks sunlight and suppresses weeds. Farmers accept it easily and it produces quick results, but the types of crops planted, the methods of crop rotation and intercropping, and whether herbicides are used a little or not at all vary farm by farm and haven’t been well modeled yet. Conservation agriculture sometimes uses both fertilizer and herbicides. It is already known that regenerative agriculture surpasses current practices in both productivity and profitability. And it’s good for the environment.

Silvopasture

Raising cattle in forests. This has been done on the Iberian Peninsula for 4,000 years. Forests can sequester 5 to 10 times more carbon than the same area of grassland. Treating forest as grazing land actually improves the soil, and eliminates the need for compost and herbicides. It may seem counterintuitive, but it’s true. The bias that trees interfere with grass growth is hard to shake. Silvopasture can be considered a variation of intercropped forestry.

Composting

Composting can prevent methane emissions. It’s a way of turning garbage into treasure. 57% of plant waste is composted in the EU and 38% in the US. The Haber-Bosch process for producing nitrogen fertilizer was revolutionary for agriculture. But at the time, a figure named Sir Albert Howard championed classical composting and opposed the Haber-Bosch method. It’s been 25 years since Denmark stopped landfilling organic matter.

Perennial Crops

Annual crops release carbon into the atmosphere every year. Grapes, bananas, avocados, and the like are perennials. They don’t damage the soil. Annual crops yield higher nutritional value per hectare, but with the right combinations, perennials may be able to match that. No need for tilling, resilience to weather variability, options for drought-resistant varieties, suitability for slopes — the transition to perennial crops costs almost nothing. Cultivation of annual crops and rice dates back to around the end of the last ice age, 10,000 years ago. In annual plants, the roots die off too, leaving only seeds. In perennial plants (sesame, rapeseed, etc.), the roots stay alive and seeds also remain. Perennial plants use less carbon during growth and also sequester carbon. The downside of perennials is that they’re hard to mechanize — you can’t just harvest them roughly with a combine.

Soil Microbes

In the 19th century it was chemical fertilizers and pesticides, and from the 20th century, genetic modification — nothing seemed possible without these. And it’s true that yields increased. But because the activity of microorganisms underground was completely unknown, no one realized the soil was being damaged. Until Jan Baptist van Helmont’s discovery in the 17th century, plants were thought to consume soil. In the early 19th century, Nicolas-Théodore de Saussure discovered photosynthesis. It was mistakenly believed that plants obtained only five essential elements — water, carbon dioxide, nitrogen, phosphorus, and potassium — from the soil, so it was thought all you had to do was supply those. Soil ecology has grasped the reality of perhaps only a tenth of soil microorganisms so far.

Managed Grazing

Overgrazing depletes land. So does driving out the grazing animals help? No — the land doesn’t return to its original state. Without grazing animals, in other words, the land can’t become rich again. Approaches include controlling herd numbers, fencing and rotational grazing, and dividing land into zones that are moved through on a set schedule. Naturally, the cattle’s behavior changes. Instead of eating tough, low-nutrient grass, they actively move around and seek out protein-rich weeds. As a result, herbicides become unnecessary. Ruminants penned inside a fence are just a source of methane, but released into open land, they help sustain the ecosystem. The problem is that this remains very experimental, with no established model. For-profit companies haven’t entered the space; it’s advanced through networks of farm owners and researchers.

Millennium Villages

Eliminating hunger and providing clean water in Africa is good, but it presupposes a continued injection of funds and isn’t sustainable. And the target is always “some one village,” then “some other next village” — it never gets standardized. Relying on agroforestry instead keeps the latest knowledge for solutions in the hands of local farmers, without needing to depend on funding or knowledge assistance from Western developed countries.

Abandoned Farmland

Abandoned farmland becomes a source of greenhouse gas emissions. But once it’s cultivated again, it becomes a carbon sink.

Rice Paddies

Rice paddies are an ideal environment for methane generation (10-20% of global emissions). They sustain a positive feedback loop in which higher temperatures increase methane generation. System of Rice Intensification: a method to increase yield by transplanting rice earlier, periodically draining the water, and adding compost while the field is dry. It’s barely mechanized, but yields double.

Biochar

Terra preta: a method long practiced in Africa of slowly charring organic matter underground in an oxygen-free state. Soil productivity lasts a long time this way. Carbon produced by slash-and-burn, by contrast, is ultimately only surface-level.

Irrigation

Old-style irrigation flooded the fields. Now it’s sprinklers. But agricultural water carries an environmental burden in terms of transport, and small-scale farmers can’t adopt it due to cost. In Asia, irrigated area is a mere 4%.

[New Technologies and New Approaches]

Intensive Silvopasture

In tropical regions, growing a diversity of plants lowers temperatures by 8-13°C. It also provides windbreaks, raises soil moisture, and improves biomass. Leguminous shrubs are planted — leucaena, for example. Leucaena increases the amount of protein absorbable before fermentation, which both increases body weight and reduces methane emissions. Efforts like this are underway in Austria, Colombia, and Mexico.

Seaweed and Ruminants

Cattle are ruminants, and in a stomach chamber called the rumen, microorganisms break down cellulose and other materials. 90% of the methane from this fermentation process is expelled through belching. Methane accounts for 25% of atmospheric greenhouse gases and 10% of all greenhouse gases combined. Dairy farmers in Canada noticed that feeding cattle seaweed eliminates methane production and also increases milk yield (some of their livestock grazed along the coast). A substance called bromoform, contained in Asparagopsis taxiformis, interferes with the enzyme that produces methane. As a result, the cow’s energy expenditure drops and milk production improves. There’s also an idea to combine this with ocean permaculture to mass-produce Asparagopsis taxiformis at sea. Researchers are looking for a method of grazing-style cultivation of Asparagopsis in the ocean.

Microbes for Nitrogen Fixation

Anaerobic bacteria convert atmospheric nitrogen into nitrates. They live in the roots of leguminous plants. The plant protects the bacteria from exposure to oxygen and gives them sugar in exchange for nitrogen.

Soil Microbiome

The potential of bacteria is still not well understood. Mutual support and symbiosis represent the healthy state of a biome.

Bacillus Thuringiensis

Corn, soybeans, and herbicides genetically modified to incorporate bacteria that kill caterpillars, moths, and butterflies are already commercialized.

Hemp

Cotton is the dirtiest crop in the world. 36 kilograms of carbon dioxide are emitted to produce a single T-shirt. Hemp is an excellent fiber-yielding annual crop. It grows fast, suppresses weeds, and can be planted densely without issue. It can also substitute for paper, but costs six times as much as pulp.

Yunnan Academy

Developed a plant that grows like a strawberry and bears rice only once every few years. It grows in highland fields rather than paddies.

Deep-Rooted Wheat

Created through repeated selective breeding. It sequesters more atmospheric carbon underground, passing it to bacteria that acidify rock. The soil becomes rich, eliminating the need for tilling.

Oysters

Oysters absorb not only carbon but also nitrogen.

[Related Link] ・Notes on Drawdown (Energy Sector)

Originally published in Japanese at https://clazytech.com/2021/12/816/. Translated with LLM assistance and reviewed before publication.