Transforming A Standard Farming Practice Into A Form Of Climate Action

For centuries farmers have used various naturally occurring minerals to correct the pH balance of their soils when they become too acidic. The practice is called “liming” and while it is particularly important for regions with high rainfall, it can also be needed on irrigated land. There are a number of sources of liming agents (e.g. dolomite, marl, chalk, slag, limestone, burnt lime…), but there is a particular liming material called Olivine that can be quarried in various locations including from major deposits in Norway. Chemically speaking the parent rock for this is Magnesium Iron Silicate and particularly pure versions are a source of the green gemstone peridot which is the traditional birthstone for August.

When finely ground, Olivine can be spread on fields for liming to serve the farmers’ soil health needs and simultaneously serve to capture carbon dioxide from the atmosphere and store it permanently in the soil. There is a company called Eion Carbon which is working to enable large scale use of this liming agent under it CarbonLock(tm) brand.

This means of “carbon sequestration” is good for the planet and for society, but it is particularly appropriate for a farming connection because agriculture is one of the most vulnerable industries in an age of climate change. Extreme climatic events like droughts and floods are becoming more common and inflict serious economic losses on farmers. Generally warmer temperatures speed up the life cycle of pests while warm nights drain yield because more of the day’s energy capture from the sun is metabolized away in the dark. Irrigation resources are shrinking in many regions. Even in the face of those challenges, farmers have some unique opportunities for climate action – ways to be a part of the solution. There are farming practices such as “no-till”, double cropping, and planting of cover crops that can lead to net carbon sequestration in farmed soils. Those same practices allow those fields to more efficiently capture and store rainfall giving them a greater degree of resilience during climate extremes. There are programs in place to allow farmers who farm this way to participate in markets for carbon credits, but it is challenging to accurately measure the amount sequestered and what has been captured could be re-emitted to the atmosphere if the land is later returned to a traditional tillage system. In contrast, CarbonLock offers a fully measurable and permanent means of sequestration. Fortunately, both the no-till/cover crop approach and CarbonLock liming can be implemented on the same fields to maximize climate-action impact.

After the Olivine is quarried it is ground down to small particles in order to speed up the carbon dioxide binding process. This is known as “enhanced weathering” since the mineral component of all soils began as rock reduced to small particles over time. The quarrying and grinding process is contracted by Eion with the Norwegian company which uses geothermal energy that is also available at its location. The material is then ocean freighted to the New Orleans which is also an energy efficient means of transport.

In the US the CarbonLock material is distributed through existing farm coops or other entities that store and deliver many products to farmers such as fertilizers and crop protection products. Typical farm level lime application rates are in the range of 1 to 4 tons per acre. For each ton applied as CarbonLock approximately one ton of CO2 equivalents are sequestered. Factoring in all the elements of the life cycle the final ratio is around 0.85 tons CO2 equivalents per ton applied.

Farmers will be able to get this product at subsidized prices that are lower than for those for other liming materials. The quantities transported sold and applied can all be tracked. Eion then sells a corresponding number of carbon credits to companies wanting to meet carbon reduction goals. The main sponsor is Stripe which is the company behind the technology used for credit and debit card data management in stores.

This technology is in the very early stages of commercialization and there are independent researchers from US agricultural universities that are confirming the details of field efficacy across multiple settings, but the basic chemical premise for how it works has been confirmed by relevant experts. Eion’s goal is to be sequestering over a billion tons of carbon dioxide per year.