Carbon farming is a suite of agricultural practices and crops that sequester carbon in the soil and in above-ground biomass.
A third of the carbon dioxide in our atmosphere has been released through deforestation and agricultural practices such as ploughing and using synthetic herbicides, pesticides and fertilizers. Plants can reverse that by taking in carbon dioxide, then by photosynthesizing they send the carbon down through their roots as sugars to where living organisms such as arthropods, nematodes, fungi, protozoa and bacteria turn it into stored carbon. Bacteria and fungi play a crucial role, combining minerals found in rocks, clay and sand with the carbon in the sugars, creating pea-sized aggregates, multi-surfaced lumps with spaces between them. Those spaces act as a sponge, holding water in times of drought and preventing runoff and erosion in times of heavy rain. If the soil isn’t tilled or saturated with synthetic chemicals, so retaining its living organisms and its structure, tons of carbon can remain there for centuries.
Scientists indicate that, in addition to cutting carbon emissions, afforestation and widespread application of carbon farming techniques could dramatically slow and even reverse global warming. After the oceans, soil is the next best carbon sink.
Carbon farming can take many forms. The simplest practices involve modifications to annual crop production. Although many of these modifications have relatively low sequestration potential, they are widely applicable and easily adopted, and thus have excellent potential to mitigate climate change if practiced on a global scale. Likewise, grazing systems such as silvopasture are easily replicable and don’t require significant changes to human diet. But by far, agroforestry practices and perennial crops present the best opportunities for sequestration. While many of these systems are challenging to establish and manage, and would adjustment of diets to unfamiliar perennial crops, they also offer huge potential that has been almost entirely ignored.
Project Drawdown (Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming by Paul Hawken) released their comprehensive list of solutions for reversing climate change; three of the top 17 solutions listed were specifically agroforestry practices: Silvopasture, Tropical staple trees, and Tree intercropping. Their analysis projected that these three practices alone could contribute to a net operational savings of over $1.3 trillion while drawing down nearly 70 Gigatons of CO2 equivalents.