Climate-Change Mitigation Potential of Biochar: A Review and Framework for Carbon Accounting

Climate change presents one of the greatest challenges facing humanity. The anthropogenic emissions of heat-trapping greenhouse gases are widely considered to be the primary driver of global warming and climate change. Climate change mitigation strategies are being considered and implemented by government and non-government organizations worldwide. One practice that has attracted attention as a tool to offset and reduce emissions of greenhouse gases is the manufacture and application to soil of charred biomass, commonly referred to as biochar. As a soil amendment, biochar can stabilize carbon belowground and potentially increase agricultural and forest productivity. It is also resistant to decomposition when incorporated in soil, and can serve as a significant carbon sink. Researchers have examined the potential of biochar to produce multiple environmental benefits including energy production and agronomic improvements, while simultaneously sequestering carbon and reducing net greenhouse gas emissions. This paper reviews current scientific literature to evaluate biochar's potential to stabilize carbon belowground, all while producing a number of other environmental and economic benefits. The feasibility of implementing biochar systems is considered in the context of carbon-market incentives that may be adapted to motivate investment in biochar production. A framework for carbon accounting of biochar projects is also presented.