Nature’s technology enables reliable carbon drawdown at a scale that matters. - Grassroots Carbon

Nature’s technology enables reliable carbon drawdown at a scale that matters.

June 19, 2023
Carbon drawdown technology can be natural

Dr. Henk Mooiweer

There are two main pathways to address atmospheric carbon dioxide levels, and thus climate change. The first pathway is to reduce or prevent CO2 emissions, which is essential for stemming the level of atmospheric CO2 and thus slowing the pace of climate change. The second pathway is to draw down the carbon dioxide currently present in the atmosphere.

Carbon drawdown technology

Considered a key factor in reducing or even eliminating climate impact, carbon drawdown aims to remove CO2 from the atmosphere and ensure it is securely stored for many years. Academics and startups are leading innovation on a variety of carbon removal and direct air capture technologies. This latter approach often uses machine-based technologies to separate CO2 present in the air, where it is captured and can be turned into materials or stored as compressed CO2 deep in the earth’s sub-surface.

Some of these carbon drawdown solutions are already attracting significant investments, but most of them are still in a technology demonstration phase. A closer look at many of these engineered carbon drawdown solutions shows that they have enormous hurdles to overcome, such as energy and material use, intensive logistics, community externalities, and often an astronomical cost to scale to any level of impact. Nevertheless, these engineered solutions stand in the limelight because they are associated with technology innovation and engineering sophistication.

To restore our climate, we need carbon drawdown technologies that are not only impactful, reliable, and affordable, but also have the ability to scale today.

This might seem like an unachievable set of requirements, unless we pause for a moment and reframe our definition of technology.

A well demonstrated carbon drawdown technology

Nature has been managing carbon flows for quite some time and has developed a sophisticated system that handles CO2 and carbon reliably, efficiently, and at a scale that matters. It starts with photosynthesis. Atmospheric CO2 and water react in the green parts of plants, using sunlight as energy, to form oxygen and sugars. This process captures solar energy and stores this energy in the chemical bonds of sugar molecules.

Photosynthesis left the demonstration phase eons ago and has been functioning effectively for at least 3 billion years. Atmospheric carbon derived plant sugars fuel many other processes that drive plant growth. Plants are well equipped to capture atmospheric CO2 .

Sophisticated and reliable carbon capture and storage

To appreciate the reliable carbon storage technology, we need to dive into the soil where plants are rooted. Healthy soil is a thriving living system. There are more microbes in a teaspoon of soil than there are people on our planet. These microbes are an essential part of the carbon cycle and play a key role in synergy with plants in storing carbon in exchange for other nutrients.

The major types of living species in soil are an ecosystem of bacteria, fungi, protozoa, nematodes, earthworms, and arthropods. Most of these species require a source of carbon for their energy and growth.

Reliable carbon drawdown at scale

Of particular importance for carbon storage is the 400-million-year relationship between mycorrhizal fungi and plants. Mycorrhizal fungi penetrate plant roots and have a strong symbiotic partnership. The root provides carbon in the form of sugar to the fungi, in exchange for minerals and water. Mycorrhizal fungi form very large underground “pipeline” networks that connect plant root systems that exchange sugars and other molecules over relatively long distances. Plants and soil have sophisticated technologies to capture and store atmospheric carbon.

It’s estimated that the total global length of mycorrhizal networks in the top ten centimeters of soil on our planet is around 280 quadrillion miles — nearly half the width of the Milky Way galaxy. In a meta-analysis published June 5 in the journal Current Biology, scientists made a conservative estimate that as much as 13 gigatons of carbon dioxide equivalents (CO2e) fixed by terrestrial plants is allocated to mycorrhizal fungi annually.

This is approximately 36% of yearly global fossil fuel emissions. The United Nations Intergovernmental Panel on Climate Change has estimated that there is more carbon stored in the first 3 feet of soil than all atmospheric carbon and global biomass carbon combined (IPCC Fifth Assessment Report 2014). The bottom line: Nature stores atmospheric carbon in soil at a scale that matters.

But how can we rely on the carbon to remain sequestered in the soil?

Nature has some experience with this technology and has optimized it over hundreds of millions of years. While the formation of the soil fungi networks is influenced by natural factors such as soil type, resource availability, plant type, soil disturbance and seasonal variation, human activity plays a key role in keeping carbon sequestered in the soil.

Human impact and detrimental land management, including mechanical tilling, overuse of synthetic fertilizers and chemicals, overgrazing, lack of cover crops and monocultures, have led to massive destruction of fungi networks and soil life. This in turn has negatively impacted soil carbon storage. It is estimated by the UN FAO that approximately one-third of the world’s productive topsoil has been depleted and contains eight times less organic matter.

Humans can influence soil carbon storage, either negatively or positively. This creates an
amazing opportunity to unlock nature’s technology to “recarbonize the soil” and reduce
atmospheric CO2 levels.

Soil carbon storage is proven and reliable if land managers work with nature rather than against it. If regenerative land management practices are used, depleted soils can rapidly transition into thriving soils that store vastly more, additional atmospheric carbon.

Some of these agricultural management practices include planting native species and cover-crops, using minimal chemicals, and employing regenerative grazing management that allows land to rest and natural forage to re-grow. Depending on the local circumstances, organic matter content, and soil type, the start of this regeneration process along with increased additional soil carbon storage can be relatively fast: think years, not decades.

Permanent impact

We exist in a living natural system that has successfully been storing organic carbon for hundreds of millions of years, and we need to expand our engineering mind beyond a quantification of machine based technologies to encompass an objective assessment of living systems.

Soil carbon storage is incredibly stable when considered at an aggregate bulk level, with land management that maintains soil health. Bulk soil carbon is, for instance, wild-fire resistant. When individual carbon-containing molecules are followed, there is very little permanence in a living system, because these molecules are continuously exchanged between, and utilized by, microorganisms. This might mean that a carbon atom present in a CO2 molecule that was captured today by plants and soil microorganisms, might be released back into the atmosphere tomorrow as part of natural carbon cycling processes.

Carbon is the currency continuously traded in healthy, living, and thriving soil, similar to money moving throughout a thriving economy. As long as the aggregate soil carbon content increases, then atmospheric carbon content decreases.

When many land managers implement regenerative practices across millions of acres of land, it doesn’t matter if a few landowners stop these regenerative practices as long as the portfolio of acreage increases its overall soil carbon content.

Carbon drawdown with impacts far beyond just carbon

When land managers manage for soil health, they create impacts far beyond just carbon. Healthy and carbon rich soils can store ten times more water and are therefore more drought and erosion resistant. Thriving ecologies with abundant and diverse vegetation, insects, birds, and wildlife re-emerge. Regenerative farms produce more nutrient-dense and therefore healthier food. Over time, land managers can also reduce their operating costs and improve the economics of their farms and ranches.

Addressing climate change requires investments in an array of carbon drawdown technologies that can succeed at a scale. Nature’s carbon drawdown technology is a sophisticated system that is readily proven and available. Land managers choosing to work with nature to regenerate and recarbonize their soils do create impact at a scale that matters.

Nature makes it easier for us to reverse the climate change we created. It is not the lack of technology that hinders the progress we need; it’s our narrow definition of what technology encompasses. We need to open our minds and appreciate the sophisticated natural technology right under our feet and give it a prominent role in eliminating climate change.