Emissions Trading and Certification Methodologies for Biochar

The 2006 IPCC Inventory Report Guidelines, which proposed a calculation method for determining the carbon sequestration (greenhouse gas reduction) of biochar input into the soil, were revised in 2019. Furthermore, the IPCC Assessment Report (AR6) on mitigating climate change, released in April 2022, states that biochar can contribute to offsetting greenhouse gases by removing atmospheric carbon dioxide, thus aiding in achieving net-zero greenhouse gas emissions. Specifically, biochar has been identified as an economically efficient resource with significant potential for carbon removal, making it a viable option for greenhouse gas reduction in national inventory reports. Moreover, international efforts are underway to develop methodologies for certifying this reduction, thereby facilitating greenhouse gas emission trading. For instance, Japan has developed a national-scale methodology, while the European Union has devised a methodology for certifying the greenhouse gas reduction of biochar in the carbon trading market. These certification methodologies encompass general considerations, such as system boundaries, methodologies for baselines, and monitoring methodologies. In the case of biochar, two factors must be considered when using the life cycle assessment methodology: soil inputs and concrete additives. Regarding soil inputs, a nationally intrinsic value must be derived for a parameter (the proportion of biochar remaining after 100 years) representing the change in organic carbon stock. For carbon sequestration using biochar as an additive in concrete products, etc., a value must be determined based on the product’s lifespan. Ultimately, this study advocates for governmental measures to develop emission-trading methodologies for disseminating carbon removal technologies that utilize biochar.