Biochar Has Potential To Enhance Agriculture In California & Mitigate Climate Change

The COVID-19 pandemic shut down large sections of global commerce in 2020, causing economic disruption worldwide. Industry slowed tremendously, which yielded significant declines in global economic output and a substantial drop in greenhouse gas emissions. As preliminary data rolls in for 2021, it is clear that international commerce is recovering. In the US, greenhouse gas emissions and GDP remain below pre-pandemic levels, but are trending upward as the economy reopens. According to an analysis by Rhodium Group, greenhouse gas emissions are up 6.2% from 2020, but are still 5% below pre-pandemic levels. Year-to-year GDP growth is 5.7%, which indicates that greenhouse gas emissions are rebounding faster than the economy. This trend is likely to continue through 2022.

Carbon dioxide makes up the lion’s share of greenhouse gas emissions produced by human activity. The pie chart above illustrates the distribution of emissions by economic sector in the US. Agriculture is the smallest producer of greenhouse gases, but will be most affected by climate change as drought and severe weather intensifies.

Following the recent report from the Intergovernmental Panel on Climate Change, it is resoundingly clear that reducing emissions by phasing out fossil fuel reliance is critical for securing a liveable future for generations to come. Renewable energy tech is here; it’s getting more affordable and needs to be widely adopted. However, is a rapid decrease in global emissions enough? Scientists say no; the creation of carbon sinks must occur in tandem with emissions reductions. The recent IPCC report doubled down on the importance of conserving existing and creating new carbon sinks worldwide. Afforestation, reforestation, and conserving wetlands and bogs are central focus points for carbon sinks. A lesser-known method for large-scale carbon capture is the application of biochar.

Human production of biochar, or Terra Preta, has been around for a long time. It has a rich history in places like the Amazon basin, where it was used to improve soil quality in areas of human habitation drastically. It is relatively easy to make, and its benefits are pretty astounding, but what is biochar, and how can it be used?

Biochar is organic matter that undergoes pyrolysis, a process where plant material is burned in a low oxygen environment to create a very stable form of carbon, bio-gas, and vapor. Biochar is porous and has a large surface area, which increases water retention in soil. Studies have shown that it increases microbial activity and nutrient availability which stimulates plant growth when added as an amendment to soils. This makes it quite valuable for agriculture operations in drought-prone or nutrient-deficient areas.

The remarkable thing about biochar is its ability to sequester and retain atmospheric carbon; because of its stability, it resists degradation and can keep carbon in soils for hundreds of years. However, the wide range of possible feedstock to create biochar creates a spectrum of quality. Not all biochar is the same, and using different materials yields different qualities of biochar. Adding high-quality and certified biochar to soils creates stable carbon sinks that last a long time. Although the biochar industry is still young, it is alive and well in the Golden State. With 27 million acres of cropland, California holds promising potential for a wide-scale application of biochar and the creation of significant carbon sinks.

Pacific Biochar, a company based in Northern California, is working to scale production by modifying biomass facilities to make biochar. By using existing infrastructure, it can scale production and produce biochar at a fast rate. Pacific Biochar uses forest biomass (debris) as the primary fuel source for its biochar production; this simultaneously mitigates wildfire risk and produces a viable soil amendment for agriculture operations in California. According to a report published in 2015 by the UC Davis Biomass Collective, the total amount of technically available biomass in California is estimated to be 35 million BDT/y (bone dry tons per year), with forest biomass constituting 14 million BDT/y. That is quite a bit of usable debris.

Pacific Biochar created a comprehensive and open-source plan called the Big California Biochar Model, which describes a scalability strategy for agriculture operations in California. The company predicts that if 100% of available forest biomass were used for biochar production at a 10% conversion efficiency, it could produce 1,430,000 BDT/y of biochar with an annual application rate of 158,209 acres of agricultural land. This has a CO2 sequestration potential of 4,207,251 tons per year, which is a significant dent in annual CO2 emissions. While using 100% of available forest biomass is unrealistic in the short term, Pacific Biochar has created a calculator where you can input different percentages to visualize the biochar production rates and CO2 drawdown potential. As of 2019, it has a near-term plan to utilize 17.5% of available forest biomass.

Corigin, a company based in California, goes a step beyond the production of biochar by using state-of-the-art technology to leverage all of the products from the pyrolysis reaction. Like Pacific Biochar, its reactor separates biogas from the reaction and uses it as an energy source, making the system carbon neutral. However, its technology can also target and whisk away vapors created during pyrolysis and condense them to create liquid bio-distillates. These distillates combine plant phenols and other biomolecules that are used as non-toxic alternatives to fertilizers. The results are exciting. The company’s products have significantly increased crop yield in field trials and cut fertilizer loads by 50%. Corigin uses agricultural waste, such as nutshells, tree trimmings, husks, pits, and other low-value residues, as the feedstock for pyrolysis. This use of agricultural feedstock creates a circular economic model that turns waste into usable and effective products that stimulate crop growth, decrease the need for fertilizer, and increase water retention in drought-prone California.

A significant obstacle that biochar companies and farmers face is the economic viability of the biochar market. It’s expensive to produce, distribute, and apply biochar, especially on large scales. However, carbon removal platforms like Carbonfuture offer an additional revenue stream to the process by issuing carbon credits to certified biochar producers and carbon-sink owners (i.e., farmers). Until state-enforced regulations are in place, the carbon credit market relies on voluntary remuneration from individuals, companies, and public institutions seeking net-zero emissions. The carbon credits minimize the financial bottleneck, ensure the people providing this vital service are paid appropriately, and drive the biochar industry forward.

Prolonged drought in the western United States has significantly stressed food production. Biochar, and the companies trying to scale it, help farmers use substantially less water, increase yields, and sequester CO2 from the atmosphere. Whether it’s Pacific Biochar’s dual approach of making biochar and mitigating fire hazards by burning forest debris or Corigin’s circular model of using agriculture waste, biochar brings beneficial changes to California agriculture and the industry’s ability to adapt to climate change.

By Jacob Tidwell