Climate Change Achieving Climate Resilient Farming Systems Through Regenerative Organic Agriculture
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May 24, 2023
Andrew Smith | Perry World House
Andrew Smith is the Chief Operating Officer of the Rodale Institute. This thought piece was written for the 2023 Perry World House Global Shifts Colloquium, “Living with Extreme Heat: Our Shared Future.” The colloquium was made possible in part by a grant from Carnegie Corporation of New York.
As the scientists, consultants, and farm managers of Rodale Institute meet with farmers across the United States and the globe, it is becoming clear that the challenges of farming, which have always been great, are becoming more difficult due to climate uncertainty. Most notable are increased heat—leading to higher evapotranspiration rates—and shifts in rainfall, with higher intensity rains during the dormant season and little to no rain during the crop-growing season. Both result in drought-like conditions during typical periods of crop growth, even with standard average annual rainfall. This variation in climate patterns makes it difficult to plan and jeopardizes food security. However, changing the way we farm and putting atmospheric carbon back in the soil may be the most practical short-term solution to not only mitigate the global climate crisis, but also manage the risk farmers face from climate uncertainty.
An excerpt from Regenerative Agriculture and the Soil Carbon Solution [white paper]
A decade ago, the United Nations Environment Program (UNEP) said we needed to limit greenhouse gas emissions to 44 gigatons of carbon dioxide equivalent (44 GtCO2e) by 2020 . If we did nothing new to mitigate the climate crisis, projections suggested that by 2020 annual emissions might be 56 GtCO2e, leaving a gap of 12 GtCO2e between the carbon already in the atmosphere and our desire to continue living normally on Earth.
In 2018, total global emissions were 55.3 GtCO2e—approaching the worst-case scenario (A seven percent reduction every year for the next decade is needed to limit warming to 1.5°C). What’s more, “accelerated soil erosion may be the second largest source of anthropogenic emissions of greenhouse gases, and its credible estimates are not known." We spent the last decade walking a path to a precipice. The emissions cuts needed now “may seem impossible,” says Inger Andersen, the executive director of the UNEP, “but we have to try” . And yet, there is hope right beneath our feet. There is a biotechnology for massive planetary rehabilitation that is tested and available for widespread dissemination right now. The cost is minimal, and it is adaptable to local contexts the world over. It can be rolled out tomorrow, providing multiple benefits beyond climate stabilization.
The solution is farming.
Not just business-as-usual industrial farming but farming like the Earth matters. Farming in a way that restores the quality of soil, water, air, ecosystems, animals, and ultimately, humanity. Farming that improves our soil’s natural ability to function so the planet and all of its life can also function. This kind of farming is called regenerative agriculture.
Regenerative agriculture revitalizes land. It is a systems approach where farmers work with nature, not against it. It is a biological model based on principles of ecology. With the farmer’s help, farm- and rangeland can lock carbon underground, thereby restoring degraded soils, addressing food insecurity, and mitigating the impacts of the climate crisis on food production. Regenerative agriculture is also our best hope for a quick drawdown of atmospheric carbon dioxide. Let us learn from regenerative farmers who have been cooperating with nature, and who have “solved for pattern." Their results are the inspiration that will fuel a wholesale shift away from the failed era of sustainability to a golden age of regeneration.
Agriculture as practiced across most of the world is not yet part of the solution—it’s part of the problem. Rather than mitigating the climate crisis, it is a net producer of greenhouse gas emissions—both directly through conventional industrial farming practices, and indirectly through land-use change and the greater food system. Agriculture production accounts for around ten percent of annual emissions (6.2 Gt CO2e). The food system at large, including fertilizer and pesticide manufacture, processing, transportation, refrigeration, and waste disposal, accounts for 30 percent or more of total annual emissions. With the widespread industrialization of farming in the mid-20th century, contemporary agricultural practices, such as synthetic fertilizers, pesticides, intensive tillage, monocropping, and yield-based management systems, accelerated the depletion of soil carbon stocks. Most agricultural soils have lost from 30 percent to 75 percent of their original organic carbon to the atmosphere due to conventional farming practices. Two-thirds of the world’s corn and wheat cropland now have less than two percent soil organic carbon. Nitrous oxide emissions have been rising due to nitrogen fertilizer overuse, and the intensification of livestock and rice production has exacerbated the release of methane (CH4).
Yet, there is hope.
These degraded soils hold the promise for regeneration. Degraded farm soils are some of the best soils on the planet to achieve carbon drawdown: they are already highly managed, they are accessible, and they have the capacity to hold a lot of carbon—all it takes are management changes to make this happen. While soils are inherently different, agricultural soils were chosen because they are productive, and they have the natural capacity to store carbon over long timescales. The Intergovernmental Panel on Climate Change (IPCC) reports “high confidence” in the evidence for soil carbon sequestration as an atmospheric carbon dioxide removal strategy.
Regenerative agriculture, with its focus on achieving positive ecosystem outcomes, can be practiced under many names: agroecology, organic, biodynamic, holistic, conservation, permaculture, management intensive grazing, agroforestry, and more. Regardless of the name, farming that sequesters carbon is already happening all over the world. Most examples come from annual cropping in temperate regions such as the US and Europe, and highlight the potential of cover crops and organic amendments in a diverse crop rotation to draw down carbon. Fewer studies of perennial systems in Mediterranean, sub-tropical, and tropical climates exist. But those studies illustrate an even higher carbon sequestration potential than annual cropping systems, especially with highly diverse, multi-strata crop patterns that mimic the local ecosystem. And we are just starting to understand the ecological and climate benefits of livestock, managed using holistic, adaptive grazing that reflects the natural behavior of large ungulates inhabiting vast rangelands. This is of special interest considering that the majority of the world’s soils are unsuitable for growing crops but can be utilized by domestic or wild animals. There will not be a one-size-fits-all approach for regeneration of degraded farm and rangeland, but the vanguard of regenerative farmers and researchers know enough now to provide guidance for each farm given its specific physical, environmental, social, and economic contexts.
Research At the Rodale Institute
Most of what we have learned at the Rodale Institute concerning soil carbon sequestration and climate resiliency comes from our forty-two-year long Farming Systems Trial. The Farming Systems Trial is the longest running side-by-side comparison of conventional and organic farming systems. The systems tested include a conventional grain crop system, which represents close to 70 percent of crop production across the United States, and two organic grain systems: low-input using only leguminous plants as a source of fertility, and a diversified and regenerative system that includes composted manure and perennial forage crops grown in rotation with grain crops.
In the first fifteen years of the trial, the organic systems sequestered carbon at a rate of ~0.85 Mg C ha-1 yr-1 (3.12 Mg CO2e), while no change was found in the conventional system. In a similar study, replacing synthetic fertilizer with different forms of compost resulted in an even higher rate of 2.36 Mg C ha-1 yr-1 (8.66 Mg CO2e). In the Farming Systems Trial, differences in soil health are most pronounced between the conventional and diversified organic systems and include significant differences in biological and physical soil health indicators. The combination of higher soil carbon and improved soil structure in the organic systems leads to greater water holding capacity and water infiltration rates. Thus, during low rainfall and drought years, yields are 30 percent to 100 percent higher in the organic systems, leading to higher economic returns to management, even without the benefit of organic price premiums in the case of the diversified, regenerative organic system. Globally, a positive relationship exists between soil carbon levels and crop yields. Crop resilience in a changing climate is an important economic co-benefit as “climate-resilient soil can stabilize productivity, reduce uncertainty, and produce an assured yield response even under extreme weather conditions”.