Biochar for Carbon Sequestering

Carbon dioxide is a greenhouse gas that anthropogenic activities contribute to. Power plant and vehicle emissions are activities that account for most of this carbon output. These activities are carbon positive. Legislation is being discussed to create a cap and trade system for CO2 in the US. Certified emission reduction (CER) credits for tons of output are issued in an open market system, allowing companies to trade un-needed credits. Capped point source emitters can choose to offset carbon outputs by participating in carbon negative projects. As CO2 increases in the atmosphere, global warming will increase and cause detrimental results. Both decreasing production of GHG and sequestering carbon will be an integral part of decreasing global warming.

One example is to sequester carbon in the form of biochar inside soil for use by microorganisms and plants. Biochar has also been shown to increase crop yield, nutrient retention, and water retention. Research has found that in combination with tilling, biochar additives to soil can actually increase the release of carbon from soil by reducing anaerobic microbial activity. However, by reducing tillage over a five year period after addition of biochar, carbon is held in the soil attached to particles. In areas of historical farming (where nutrients have been depleted and soil compacted) biochar reintroduces carbon and nitrogen and increases pore space for roots to grow deeper. This can increase yield, which will decrease the use of chemical fertilizer, land use for food production, and increase profits for farmers while reducing the progression of GHG.

“Soil already holds 3.3 times as much carbon as the atmosphere, according to a submission by the United Nations Convention to Combat Desertification (UNCCD).” Soil can hold much more than this amount. Recent proposals to UNCCD have submitted biochar as a carbon offset strategy to be included in the Kyoto Protocol. Under the Kyoto Clean Development Mechanism, point source emitters could sell credits they reduce by using biochar.

Other federal biochar legislation includes the Research and Demonstration of Biochar Program in the Farm Bill of 2008. This provided federal grant money to those promote biochar technology. State CO2 reduction measures include projected plans to use biochar to sequester carbon as well. In North Carolina, objectives include increasing biochar research, cost share for no-till practices for five years, and increased organic production by 2030. If biochar is approved as a carbon sequestering process, legislation creating a carbon cap and trade system will promote use of this technology.