Soils: The Underdog of Carbon Capture

By: Gabrielle Bastien (c) 2021

If you’re reading this, you probably need no convincing of the existence of climate change and its impacts. 

Most people are currently aware that burning fossil fuels has led to increased levels of carbon dioxide in the atmosphere, that the heat-trapping nature of this gas means our climate is warming, and that this is all happening at an unprecedented rate, causing more frequent and severe extreme weather events, etc. There’s much more to this story, of course – and I’ll bring important nuances to it later in this article – but overall, this is the narrative that’s now part of public consciousness.

What many people still don’t know, however, is that one of the solutions to this existential crisis lies beneath our feet: it’s the soil. 

This handful of soil contains an intricate ecosystem of countless micro-organisms, more numerous than the human population on the planet.

Most climate solutions we hear of focus on emissions reductions, and that’s problematic. Don’t get me wrong, they are absolutely necessary: if we are to reverse the current warming trend, we imperatively need to reduce the rate at which we are adding greenhouse gases into the atmosphere. Do you see what’s wrong with this concept? Even if we reduce our emissions as much as we can, we’re still accumulating more heat-trapping gases around our planet. Unless, of course, we simultaneously focus on solutions that capture these greenhouse gases. 

When developing solutions to such global/existential issues, many people rush to include technology. However, like for any good solution, one needs to ask themselves certain questions before jumping on the technology bandwagon: How much energy and resources would this take? How much would it cost? What’s the life cycle impact of this technology and what does it achieve? Who benefits from it? Could a natural solution do the same at a lower cost and with fewer resources? In this case, we’re lucky to benefit from the most effective and democratic ‘technology’ for carbon capture we currently have available: photosynthesis, which enables plants to channel carbon into soils.

Soils are one of the things that make our planet unique. They’re a combination of mineral elements, air, water, and biology. Yes, biology; soils are alive. They host an intricate ecosystem of countless micro-organisms, more numerous in one handful of soil than the human population on the planet. These micro-organisms break down previously living tissue to make nutrients available to plants, and excrete gooey matter that creates clumps which give soil its unique structure, enabling air pockets for roots to grow and allowing water to infiltrate. 

Healthy living soils provide countless ecosystem services, some that we take for granted every day: growing plants and sustaining above-ground biodiversity, filtering water, and regulating droughts and floods. Additionally, as the biggest terrestrial carbon reservoir – containing 3 times more carbon than the atmosphere in its first three meters – soils also regulate the climate.

Before settlers arrived at Turtle Island (North America), the prairies were diverse ecosystems with rich topsoil that reached several feet deep. With industrial agriculture, this incredible resource we had has largely gone up in dust. Heavy tillage disrupted the soil biome’s habitat and exposed it to sunlight, wind and rain, causing erosion, leaching and oxidation. Heavy applications of chemical fertilizers and pesticides inhibited soil biology and contaminated soils and groundwater. Along with deforestation and urban sprawl, industrial agriculture has caused intense degradation of our most valuable resource – our soils. And as soils degrade, they lose their carbon content which is largely emitted into the atmosphere as CO2. Since its very beginnings 12,000 years ago, agriculture has caused the loss of 133 Gigatonnes of carbon from our soils.

So here is a first clarification on the common climate narrative I mentioned above: CO2 accumulation in the atmosphere is not just due to burning fossil fuels and forests. Soil degradation caused by land use change has been a major contributor to human-caused climate change as well. 

Degrading soils are not just devastating due to their impact on the climate; Soils are the source of most of our foods. If we want to sustain our ever-growing human population, we cannot afford for soils to shrink in size and functionality over time. Yet at this stage, we lose about the equivalent land surface of Pennsylvania – 12 million hectares, or 120,000 km2 – to desertification, every year. Degraded soils have also led to heavy leaching of toxic chemicals and nutrients into our water bodies, generating severe water pollution issues globally. As our soils have steadily become poorer in quality over time, the foods they grow contain less and less nutrients, leading to further health issues in addition to those caused by the toxic pesticide residues we ingest.

ONE THIRD of our soils are degraded worldwide.

Before we get to the good news – because they are coming, I swear! – I want to point to a process that is rarely discussed. As soils degrade, they also lose their capacity to absorb water. It is well understood that this means less resilience to droughts and floods: if precipitation is scarce, degraded soil won’t have a water reserve to rely on; and under a heavy rainfall, much of the water wouldn’t be absorbed and would simply runoff, bringing with it soil and toxins into waterways. What is less understood is that soil health actually impacts the water cycle, and that this is the main reason why it influences the climate. 

Picture a degraded area: with less water stored in the ground and fewer plants growing upon it, there will be reduced evaporation, and thus fewer clouds, and less precipitation. Evaporation from plants has a cooling effect – just think of how cool it feels in a forest, as opposed to in a desert under the scorching sun. This is just one piece of the significant impact of hydrology on our climate. In fact, water cycles govern 95% of the heat dynamics of the planet. And given that evaporation from land is responsible for 40% of the water cycle (the rest being evaporation from the oceans), soil health and vegetation have a tremendous effect on hydrology in a given area, and therefore, on the climate.

So here is my second clarification regarding the climate narrative: the planet isn’t warming only because of a broken carbon cycle. More importantly, the planet is warming because of a broken water cycle. 

We’ve gotten to the good news: this vicious cycle of soil degradation, broken water cycles and climate change can be reversed. By regenerating the health of our soils, we mitigate climate change by absorbing atmospheric carbon and restoring water cycles; enhance our resilience to extreme climate events by increasing the soil’s capacity to absorb water; improve the cleanliness of our waterways by restoring the soil’s ability to filter water; enhance biodiversity; and increase the nutritional quality of our foods. A win-win-win solution, across the board.

How do we do this, then? Surely this must be complicated? Well, it isn’t, and it is. Like many solutions to complex issues, the principles of regenerative agriculture – or, more broadly speaking, regenerative land management – are remarkably simple. Overcoming the barriers to implementation is, of course, a different story. Unsurprisingly, the principles of regenerative agriculture – which we define as a set of agricultural practices that regenerate the health of the soil and improve its ecosystem functions – mimic nature. Many professionals say it comes down to working with nature instead of against it. This means covering the soil, disturbing it as little as possible, feeding it with organic inputs as opposed to chemical ones, fostering biodiversity in and around agricultural systems, integrating perennial plants with deep roots such as trees where possible, and integrating animals who play an important role in all ecosystems. In simple terms, this is what regenerative land management comes down to.

These regenerative practices have the ability to enhance carbon sequestration into soils through different pathways. Through photosynthesis, plants take in carbon dioxide from the air and convert it to liquid carbon which is secreted through their roots. This liquid carbon feeds soil microorganisms which help to cycle nutrients from organic matter in the soil and build biomass through plant growth. In an industrial system, biomass is largely harvested and taken out of the cycle, so little stable soil carbon remains. In a regenerative system, more long-lasting forms of carbon remain in the earth, hence the excitement about it all. Regenerative agriculture not only leads to tremendous environmental, economic and social benefits as listed above, but it even mitigates climate change by offsetting our global emissions.

Many farmers are already putting these land management principles into practice across Canada. Take Brooks and Jen White, for example, who run Borderland Agriculture in Pierson, Manitoba. Diversity is the name of the game on their 5000-acre farm. On many parcels, they grow two different crops in an intercropping system, to increase the beneficial relationships the two plants might have. They trial different combinations of crops in their multiple fields to see what works best. On other parcels, they’ll plant a cover crop between rows of their main crop, to keep the soil covered and foster biodiversity. They also have several fields of native perennial grasslands, on which they graze a large herd of bison. And they even graze their bison in some of their crop fields, after harvesting, so that these fields benefit from the manure, trampling and grazing activity of the livestock. 

Borderland Agriculture – a farm that puts regenerative practices into place.

Through these practices, Borderland Agriculture has been able to cut down on expensive chemical inputs, while also reducing their fuel consumption. “We have reduced our fertilizer use by 75%, and we have reduced our chemical applications by 50%,” Brooks said. They have also seen increased microbial activity and improved water infiltration in their soil.

So innovative regenerative farmers are out there and have been seeing great results – on the health of their agricultural system, resilience, profitability, and sometimes even yields. If implemented on a large scale globally, this could be a tremendous contribution to alleviating many of our world’s most pressing issues. Yet regenerative agriculture is certainly still not the norm in Canada, due to different barriers.

For one, there is a lot to be done to raise awareness and provide access to knowledge about regenerative practices for farmers in the current system. Agronomists are generally not sufficiently trained in soil health and regenerative practices, and transfer channels for these techniques are rarer. There are also important economic barriers for farmers wanting to make a transition, both in terms of time and resources invested to learn new ropes and redesign their system, as well as in initial investments needed for new equipment. And there is currently a lack of institutional support for farmers undergoing this transition. For instance, farmers implementing certain regenerative practices aren’t eligible for certain crop insurance, and there has also been a lack of government programs and policies to support these innovative practices. That’s without mentioning the social pressure and cultural barriers farmers face that might bring resistance to change.

At Regeneration Canada, we work to overcome some of these barriers. By engaging with a diverse network of farmers, agronomists, researchers, businesses, non-profits, policymakers, and citizens, notably through our Living Soils Symposium, we’ve contributed to raising awareness about this solution across the country and to provide farmers and agronomists with access to technical knowledge on regenerative practices. By making citizens aware that their food choices can play a role in mitigating climate change and by connecting them to regenerative farmers, we’ve helped set the stage for farmers to build regenerative markets. And by building a movement of citizens eager to see this solution implemented on a large scale, we’ve helped set the stage for policy change.

Excitingly, the winds have started shifting. In the past two years, we’ve seen a drastic increase in mentions of regenerative agriculture in mainstream media. The recent budget announcement by the federal government of Canada, which included an investment of $260 million dollars towards practices that help regenerate the health of the soil and recognition of these practices as climate solutions, was a tremendous win. We’re proud to have been a part of advancing policy proposals with Farmers for Climate Solutions which have resulted in concrete investment from our government. 

Much more work is to be done. But we’re hopeful that the right elements are starting to be in place for a major shift. After all, regenerating our soils is a win-win-win for all of us, so there’s no reason not to do this. 

How beautiful is it to think that we could leave our planet in a better state than we inherited it in?