How Soil Microbes Store Carbon

So, how does the process of soil carbon drawdown function? In simple terms, microbes are responsible for absorbing and retaining carbon. Plants play a crucial intermediary role by photosynthesizing: they take in carbon dioxide from the atmosphere and, with the help of water, sunlight, and minerals, convert it into sugars and carbohydrates. Remarkably, plants then exude approximately 30–40% of these sugars into the soil as nourishment for their microbial partners.

The microorganisms—primarily soil fungi, along with some bacteria, protozoa, and nematodes—utilize this carbon and store it as organic matter or within their own bodies, especially in fungal networks. Through this ancient ecological mechanism, carbon is drawn down from the atmosphere and sequestered in the soil. For a more detailed explanation of this intricate process, check out my comprehensive article on the science of soil carbon sequestration in accessible language.

Incentivizing Farmers to Combat Climate Change?

Soil is finally receiving the recognition it deserves, and it's encouraging to see both ecological farmers and soil scientists taking notice. However, there's a significant gap in understanding among the general public and policymakers regarding soil's role in climate solutions. The Biden Administration has suggested offering carbon credits to farmers as an incentive to lower carbon emissions and enhance carbon sequestration on agricultural lands.

The challenge? Scientists have yet to develop a dependable method for measuring soil carbon sequestration across extensive areas. Moreover, it's often overlooked that many farms—especially those operating under industrial monoculture practices—must radically alter their farming methods just to offset their carbon emissions, let alone achieve a net drawdown from the atmosphere. This is largely because most soils have been degraded to the point of becoming mere dirt, which is incapable of sequestering carbon.

Living Soil vs. Lifeless Dirt

Conventional agriculture is far from sustainable, much less regenerative. The widespread use of synthetic pesticides, fertilizers, herbicides, and fumigants has decimated soil life, leading to dire health and ecological consequences. According to the United Nations, an alarming 30 soccer fields' worth of topsoil is lost every minute due to erosion, chemical degradation, and tillage. As a result, modern conventional farming practices are rapidly transforming fertile soil into lifeless dirt.

Additionally, tillage itself releases carbon emissions back into the atmosphere—not just from the fuel used by tractors, but also by disrupting the microbially rich organic matter that has sequestered carbon for centuries. Simply put, conventional farming methods that rely on heavy machinery and chemicals are obliterating soil health, rendering it incapable of storing carbon due to a lack of microbial activity. Thus, transitioning to organic, ecological, and regenerative farming methods is essential for achieving our carbon drawdown objectives.

Assessing Soil’s Carbon Storage Potential

Currently, atmospheric carbon levels hover around 410 ppm, the highest recorded in the past 450,000 years, according to ice core samples. The United Nations suggests that a "safe" level would be 350 ppm, meaning we need to remove approximately 60 ppm—or around 450 billion tons of CO2—from the atmosphere. Can soil help achieve this goal?

The truth is, we don’t have a definitive answer yet. As previously mentioned, scientists have not fully mastered techniques for measuring soil carbon sequestration due to the dynamic and expansive nature of soil ecosystems. However, a 2019 report from the Intergovernmental Panel on Climate Change indicated that global croplands and grasslands could potentially capture and store up to 8.6 gigatons of CO2 annually.

Dr. David Johnson from New Mexico State University demonstrated that using biological farming techniques could sequester up to 20 tons of carbon per hectare each year with fungal-dominated compost. Furthermore, Dr. Elaine Ingham’s Soil Food Web, Inc. claims that if soil regeneration techniques were adopted globally, we could reverse climate change through soil carbon sequestration in as little as 15 years. There is considerable optimism surrounding the potential of soil!

The Power of Small Changes

To truly make a difference, we need to think small—microscopically small. Change is feasible if consumers, scientists, producers, and policymakers collaborate on genuine solutions rather than superficial “band-aid” fixes funded by agrichemical companies. It is crucial to recognize that one cannot promote “regenerative” farming while relying on tillage or chemical applications, as this is either misguided or disingenuous.

The good news is that regenerating soil ecosystems is relatively straightforward and quick if farmers are willing to shift their perspectives. Leading soil scientists and researchers, such as Dr. Elaine Ingham, Nicole Masters, the Rodale Institute, John Kempf, and the Savory Institute, have convincingly demonstrated that authentic soil regeneration and carbon sequestration are indeed achievable.

Now is the time to educate ourselves, share knowledge, and make conscious choices with our purchasing power. A simple way to support this movement is by buying food from organic and regenerative farmers who are actively rejuvenating our soils.

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