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By Albert Bates and Kathleen Draper
Visionary excerpt from the book BURN: Using Fire to Cool the Earth (pages 209-217)
Let us imagine: A coffee-growing village risks being carried away by mudslides that follow brush fires where the forest has been battered by hurricanes and then cut down to open the sky for coffee bushes. What things are scarce? In no particular order:
- cooking fuel
- secure shelter
- productive employment
- birth control
- health care
What things are overabundant?
- unemployed people
- climate change
Let’s see which of these things we can match up and cancel out. What we are about to describe is a carbon cascade.
The design team observes that the hillside needs to be planted with vegetation. It is especially important that the hilltops be forested. A keyline analysis will show where water wants to go when it rains, and how best it can be held high in the landscape and directed both to subsurface flows and to dam storage for the dry season. Alley cropping along the contours follows hand-cut swales, or machine-cut where financial capital substitutes for social capital.
The berms can be planted with successional understory (in this tropical example, pineapple, casava, ginger, allspice, coffee, and medicinal herbs), mid-level canopy (banana, papaya, moringa, cacao, tree legumes of mimosa, cassia, and pea subfamilies), and eventual overstory (coconut, ramon, samwood, mahogany, cedar, breadfruit, bamboo, and peach palm). Between the alleys will be seeded supergrasses like kernza, sunn hemp, pennisitum, pearl millet hybrids, brassicas, amaranth, and others, as well as familiar food crops including maize, yam, and beans where soils and water supply are well suited.
As much as possible, the planting process can be accompanied by biofertilizers having a high percentage of finely pulverized biochar, activated indigenous microorganisms, some immediate food for those microbes (such as composted food wastes and manures), and minerals keyed to redress local soil deficiencies or acidity. If these biofertilizers are not immediately available for the first plantings, they can always be added later.
Water in pond storage on the hillsides is edge-planted with Acoris, a plant that inoculates the water with a mosquito-larva-destroying resin. As the plant matures, pools and dams progress from being mosquito generating to mosquito decimating. In the lowlands, water that overflows from catchments above is directed to chinampas, constructed wetlands composed of alternating islands and channels and rotating between aerobic (horizontal and vertical flow reedbeds) and anaerobic (settling lagoons) seeded with aquatic and semiacquatic plants (taro, Chinese water spinach, lotus, azola, rice) and freshwater fish (aquaculture). Acoris for mosquito control can also be planted here, but the fish do most of that work already, so the plant is only needed in mudflats and places the fish cannot go.
Within the first season, the hillside mud problem is eased, deforestation is halted, and food scarcity begins to be alleviated thanks to the fast-yielding varieties of annuals, perennials, and fish. Productive employment can expand this system as much as available land permits, even on relatively steep hillsides. Resentment diminishes. Hope emerges.
Employing Ostrom’s formula, most resource appropriators participate in the decision-making process, decisions are monitored, violators are sanctioned, conflicts are mediated, and multiple, cooperating layers of nested enterprises are set in motion.
Within the village a regenerative, biological energy system arrives to replace the fossil fuel (diesel electric) grid-based source that previously had supplied electricity only intermittently, occasionally frying phone chargers and boom boxes. This system consists of a biomass furnace, running on the woody wastes from coppice (coffee, moringa, and cassava), coconut, rice or other shell crops, pelletized supergrasses (sunn hemp, leucaena, etc.), and other biomass after extraction of leaf protein.
The loading dock at the biorefinery receives row materials harvested from the farms. Leaves of tropical legumes are taken by conveyor and chopped into 2-centimeter pieces, soaked in 2 percent sodium metabisulfite, disintegrated in a hammer mill, and pressed in a single-screw press. The expressed juice is heated with steam (produced by the furnace) and protein coagulum collected, centrifuged, and pressed, then spread in a thin layer on glass plates and dried in an air-filtered, dehumidified room. It is then collected as a powder and containerized to be used or sold as a feed supplement.
At the most basic level, high-protein, high-quality leaf protein fractionation is simple. Production is geared to consumption by farm animals to reduce food safety, preservation, and storage concerns. Later improvements can produce dried leaf extracts for human consumption, but higher capital costs are incurred and clean-room protocols by workers become essential.
Following leaf protein extraction, the dried mash from the press is used as a feedstock for the gas retort, where it joins other dried agricultural wastes: coppice wood, prunings, bamboo thinnings, pallets, coconut coir, and nut and rice husks. All this is pyrolyzed, the heat captured during the run of the leaf protein process and produce electricity (directly, with a Sterling or Minto heat engine, or indirectly, with an internal combustion, gas, steam, or diesel-fueled engine), and co-products (fractionated volatile gases, wood vinegar) are drawn off before the final product – high-quality biochar – is left.
The biochar is quenched (if destined for soil use, preferably with urine or snuffed with manure because that adds nutrients), pulverized, and charged (blended with microbe-rich aerobic compost) to make a potent “cool” biofertilizer. Alternatively, it is kept at food grade and sold as a dry product for use as a food supplement, animal feed probiotic, water filtration medium, or deodorizer. It could still become biofertilizer, after undergoing one or more of these other uses. At less than food grade it can be used as a litter amendment to reduce smells in animal enclosures, improve the fermentation of silage, or go into various natural building materials – paints, dyes, plasters, wallboard, and bricks.
Styrofoam clamshell food containers, which are ubiquitous from take-out restaurants and shops in the cities and often wind up just floating away on ocean currents, never to be destroyed, are collected and brought to the biorefinery. There they go into an acetone bath, and the dissolved liquid is blended with low-grade biochar and poured into molds to dry. The resulting hard resin is mold proof, waterproof, non-degradable, lightweight, and durable. Depending on the dies and molds, it can become a variety of products – extruded lumber, roofing tile, chalk, surfboards, fishing boats, life vests, doors, bicycles, and ice chests. If there is a surge in demand for a particular product – refrigerator deodorizers or animal feed supplements, for instance – or there is a surplus of some particular feedstock – bamboo knocked down by a storm – the biorefinery can shift its production pattern to take advantage immediately.
This system sequesters more carbon than it emits, so we call it “cool”. By adding biochar, mineral-rich compost, and microorganisms to nutrient-poor or eroded soils, we can jump-start soil productivity and boost farm incomes. The gains in those alley-cropped contours might be anywhere from 30 percent to 300 percent vegetative growth, depending on the type of plants and the quality of the soils; poor soils will likely produce higher performance gains than good soils. Positive results can also be seen for fish and livestock fed the leaf protein and biochar nutraceuticals. Poultry can freely range the alleys to the benefit of both plants and animals. Grazers can be moved through rotational pastures that take advantage of water reservoirs and high-quality supergrasses. Gourmet mushrooms such as morel (Morchella var.) can be preblended with the biofertilizer and seasonally harvested.
Growing nurtient-dense, no-till, organic food and perennial fibers on marginal lands, using bioenergy and biofertilizers, creates a resilient, circular bioeconomy. Like Mother Nature, these systems waste nothing. Nothing need leave the system. Neither raw material nor pollution – representing the depleting wealth of the land – leave the system. What does leave are high-value, locally produced products – providing return on social capital invested. This is the “Cool Farm”.
Transportation presents an energetic challenge in the new solar-based carbon world. Nearly all modern forms of transportation evolved in an era of cheap fossil energy and diminish in economic viability when costed on renewable sources and life cycles. Diesel-powered semi-tractor-trailers and locomotives will need to be re-imagined and likely replaced or retrofitted. There could be new generations of electrified towpaths for barges and gondolas, magnetic levitation rail, and other innovations, but these costly innovations may be fragile in an era marked by overpopulation, resource constraints, and economic contraction. They are unlikely to provide a stable foundation for local commerce. We could see the return of barge, sail, and animal-powered transport.
If taken to global scale – rotational planting an area the size of India each year, converting to Cool Farms and installing Cool Labs in every village – the price of captured carbon per ton would drop from more than $200 to $20. Moreover, while most other forms of carbon capture and storage require uncompensated operating and maintenance costs, the Cool Lab is immediately profitable. It represents continuous and adaptive economic development – antifragile profits, not ongoing expenses – as well as gains in ecological health and biodiversity. It ticks the boxes for sustainable development.
In contrast with the forty-five-year gradual expansion of soybean cropping from early 1960s to reach 200 million hectars (772,000 square miles) today, Cool Farms, employing integrated agroforestry, offer up to five times the protein per hectare of soy while providing a far greater, and more immediate, return on financial investment.
Cool Labs leverage the existing financial and technological landscape of the world today but reimagine the way products are produced. The number of possible cascades is limited only by the imagination, skills, and willingness of local residents. We are at the dawn of a new kind of lean, clean, nature-centered economy. The entire system heals the earth, rebalances carbon, and generates economic security and resilience for more people.
Carbon cascades can turn almost any human settlement into an ecovillage, although the criteria for what defines ecovillage must necessarily include a few more elements than merely having a Cool Lab or permaculturally designed support systems. Ecovillages are based on a cohesive worldview, an abiding respect for the ecological integrity of your home, a circular local economy, and a culture of peace and mutual respect. Depending on your starting point for each of these elements, bringing all of them into harmony can take time and effort.
We asked former NASA engineer Frank Michael to give us the drawdown numbers from the energy and food production system we’ve outlined, taken to global scale (covering 20 global hectares of low-productivity land). Michael said we could sequester carbon from the atmosphere at the average rage of 8 GtC/yr over the first eight years, and reach 13.6 GtC/yr by twenty-four years. We would achieve the cumulative storage of the 600-700 GtC required to bring atmospheric carbon back to preindustrial levels within about fifty years, taking into account the oceans’ Co2 outgasing feedback and other black swans. Carbon would be stored in the world’s soils and living biomass and could therefore provide additional benefits beyond sequestration. Were nations to collectively phase out fossil fuel emissions, the reduction targets would be achieved much sooner. It is possible to recover the Holocene.
In April 2018, Hans-Peter Schmidt, whom we met previously, joined four other authors on a paper published by Environmental Research Letters titled, “Biogeochemical Potential of Biomass Pyrolysis Systems for Limiting Global Warming to 1.5’C.” The authors showed that by adding two other cascades to the biomass-to-biochar-plus-energy process – bio-oil (pumped into geological storages) and permanent-pyrogas (capture and storage of CO2 from gas combustion) – the land requirement dropped by up to 60 percent, while the benefits from yield increases could, in time, diminish land requirement by another 3-38 percent. The equivalent drawdown volume of greenhouse gases Michael had calculated would require 10 billion hectares (38.6 million square miles). Equally careful as Michael to observe biodiversity and cultural guardrails, Schmidt and colleagues estimated to only need 82-362 million hectares. Three hundred sixty-two million hectares (3.6 km2, or 1.4 million square miles) may seem like a lot of land, but we know from standard reference studies that there are at least five times that available in low-productivity, marginal lands in need of soil revitalization and ecosystem regeneration.
Adding one percentage pint of soil organic matter means that around 27 metric tons of organic matter per hectare (12 short tons per acre) enter the soil and remain there. Around two-thirds of organic matter added to agricultural soils will be decomposed by soil organisms and plants and given back to the atmosphere as CO2, CH4, and N2O from that metabolic process. To add permanently 27 tons, a total of 81 tons of arganic matter per hectare (33 per acre) is required. This cannot be done quickly or i just washes or evaporates away and can overwhelm ecosystems. A slow process is required.
An example of how this could play out in Costa Rica, Haiti, Africa, or anywhere else can be seen in the Loess Plateau of northern China where fertile soils were overworked until they had to be abandoned. At the time of abandonment organic carbon concentrations had dropped to under 3 percent. Thirty years later Loess soils had regained concentrations of 6 percent by persistent human effort to aid natural processes. If natural restoration were accelerated by amending soil carbon in both metabolizable forms (including crop litter, manures, food waste) and recalcitrant forms (such as biochar), the process pick up speed. This could happen virtually anywhere.
Coral reef scientist Thomas Goreau told us that at typical current levels of carbon farming it would take thousands of years to draw down excess CO2, but biochar and enhanced mineralization could draw it down in as little as decades. If recuperation of soil carbon became a central goal of agricultural policies worldwide, it would be possible and reasonable to set as an initial goal the sequestration of 1/2 ton per acre-year (1.5 t/ha-y or 500 gram per m2-y).
A farm that switches to organic, animal-powered no-tillage methods can sequester 1-4 tons of organic matter per acre (~2.5-10 per hectare) per year. By employing perennial polycultures, rotated pastures of grazing animals, trees, and wild plant strips, that amount can be doubled or tripled. As soil conditions improve, erosion and pests decline, and the land comes back to into balance, our target goal could be increased, up to a point at which the land itself responds, telling us that further gains are unlikely or marginal. Farming this way globally could sequester about 8 percent of the current total annual human-made emissions of 10 gigatons of carbon. However, the fertility gains (equivalent to more than all current global fertilizer production) would mean that chemical fertilizers could be (and should be) eliminated where this style of carbon farming is practiced. By reducing emissions of nitrous oxide from fertilizer (equivalent to approximately 8 percent annual human-made greenhouse gases) and the transportation and energy impacts of fertilizer production, we shave some additional percentage points off global emissions.
Even a modest start, such as by elevating the soil carbon content of existing farmed soils by 0.4 percent, could have the potential to offset global greenhouse gas emissions by approximately 20 percent per year. By mid-twenty-first century, we could increase the total world reservoir of carbon in the soil by two percentage points, taking that much away from the atmosphere and oceans. In this way it is conceivable to restore our soil carbon reservoir to 10 percent and even to regreen and reforest equatorial deserts and, in so doing, end the climate crisis.
More importantly, it can pay for itself and go anywhere and the social cascades can have as big a payoff as the economic and environmental benefits.