BY DR. MARGARET REEVES
Eric Toensmeier’s book, “The Carbon Farming Solution,” is an encouraging and inspiring presentation of the power of regenerative agriculture to reverse climate change within our lifetime. Deftly integrating explanations of science, local knowledge and public policy opportunities, Toensmeier shows how and why regenerative agriculture can and must be central to collective global action to address climate change. Policymakers, students, consumers, farmers and all those concerned with the future of farming in a changing climate will gain from reading this book.
The book, completed shortly after the 2015 Paris climate talks, examines many of the key issues raised there. With passion and eloquence, backed by solid, scientific evidence, Toensmeier argues that highly diverse agriculture has tremendous potential not only to mitigate the effects of climate change, but even to reverse the trajectory of the climate change processes already underway. We are at a crucial tipping point with a need to draw back down some 200+ billion metric tons of carbon dioxide (CO2). That’s a LOT, but if there’s any chance of reversing course, regenerative agriculture must be front and center. From practice to policy, Toensmeier shows how we can protect the planet and nourish 9.5 billion people (noting that we currently produce enough to feed 14 billion but fail to do so). In short, we need to “place carbon farming firmly in the center of the climate solutions platform” by allocating climate mitigation funds to the millions of people around the world who are already doing the work and thereby help ignite a massive movement to transform global agriculture.
This well referenced, easy-to-read textbook is a toolkit of principles and practices of regenerative agriculture around the globe and across millennia — from tropical home gardens to temperate permaculture, from well-established to experimental. Climate mitigation potential, as measured by carbon sequestration and reduction in greenhouse gas (GHG) emissions, is presented for multiple systems, ranging from modest potential of the best managed annual cropping systems, to great potential of complex, highly diverse, multifunctional, multifaceted systems characterized by the inclusion of perennial herbs, woody species and livestock. Importantly, Toensmeier also characterizes practices by the relative ease and readiness of their implementation. Book chapters are organized by crop types (e.g. food, fiber, fuel) and cover about 700 different crops across all climates and geographic regions in which agriculture occurs.
Multiple benefits of carbon farming
Carbon farming can potentially sequester more than 100 billion tons of carbon (equal to 367 billion tons of CO2). In addition, Toensmeier shows, carbon farming is multifunctional, producing combinations of food, fiber, building materials and biofuel; protecting water resources and pollinators; and improving soil quality and productivity. For every 21 tons of carbon sequestered per hectare (2.5 acres) of cropland or pastureland, there is an increase of about 1 percent of soil organic matter — the lifeblood of soil health and productivity. About 70 percent of the world’s 5 billion hectares of farmland are in pasture. “Improved pasture” practices are relatively easy to adopt but sequester only low to medium amounts of carbon. Nevertheless, even small increases in soil carbon on 70 percent of the Earth’s farmland can make a huge difference; intensive silvopastoral systems can sequester much more.
In contrast, most annual cropping systems are net GHG emitters. These constitute about 89 percent of non-pasture farmland. Only four crops occupy the vast majority of cropland: wheat, maize, rice and soybeans. Though conservation practices already exist on 10 percent of cropland, they generally have low carbon sequestration rates, with the possible exception of regenerative organic farming. A more robust solution is offered by agroforestry systems that sequester by far the greatest amount of carbon at 10-40 times the best annual or managed grazing systems. Agroforestry is described in some detail in the book, not as a random incorporation of trees on farms, but rather as “intentional, intensive, integrated, and interactive.” Furthermore, in addition to carbon sequestration, agroforestry systems provide added benefits including reduced need for fuel, fertilizers and pesticides. Agroforestry is currently practiced on about 100 million hectares globally.
Perennial crops constitute the core of agroforestry systems and the heart of carbon farming. There are about 20,000 edible perennial crops, 6,000 of which are cultivated for food, fodder, materials, chemical, and energy with only about 100 fully domesticated for food along with about 30 industrial crops. Many perennial staple crops — cereals, pulses (including beans), oilseeds, tubers — are economically competitive with annual staples, especially in humid and tropical climates. In colder drier climates, the yields of most perennial staples still fall below those of annual crops, although current efforts to improve perennial grains show promise.
Moving forward: From practice to policy
From practice to policy, Toensmeier presents a necessary and dramatically different vision of the future of agriculture. Enabling policies include carbon farming financial systems such as carbon taxes, rather than carbon offset programs (typical of cap and trade policies) in which polluters still pollute but pay others for implementing carbon-sequestering practices. Most such policies do not actually reduce GHG emissions; and most do not fund agriculture. Furthermore, despite higher productivity of small farms, most offset projects require huge amounts of land; and there are currently no effective mechanisms for aggregating small farms for joint financing. Concomitant with policies that support carbon farming must be the removal of national and international policy barriers that continue to promote carbon- or GHG-emitting industrial-scale farming practices at the expense of regenerative, community-based practices.
The technologies to be promoted must be scale-neutral with potential for viable small-scale and medium-sized operations. Yet more important than the technical tools, are the social systems in which they are applied. Toensmeier argues, rightly so, that farmers and farm organizations must be the leaders in implementation of practices and in the identification of enabling policies necessary to drive the process of transforming agriculture locally, regionally and globally. Such policies must be rooted in community development, community self-reliance and food sovereignty. Encouragingly, he points to well-established farmer movements such as Brazil’s Landless Workers’ Movement (MST) and the International Peasant Movement (La Via Campesina) that are already leading the way.
Toensmeier provides a practical understanding of the science of carbon farming, the power of regenerative farming to reverse climate change and the endless possibilities for transforming global agriculture. Innovative farmers around the world are demonstrating every day how this can be done.
Margaret Reeves, Ph.D., is senior scientist at Pesticide Action Network, a not-for-profit focused on fostering just and productive food systems. Prior to joining PAN in 1996, Reeves worked in Central America to improve productivity of low-input, ecologically sound agriculture. For more information go to: www.panna.org.