One of the most critical characteristics of biochar as a climate change mitigation technology is its long-term stability in soil. Quantification of the stable carbon component of biochar can facilitate the participation of biochar projects in international carbon markets, providing an additional revenue stream to projects delivering greenhouse gas emissions reductions through soil carbon sequestration. The Biochar Carbon Offset Methodology—currently under review at the American Carbon Registry (ACR), a leading carbon offset registry—includes a quantification methodology for this purpose (for additional information on the climate benefits of biochar please visit http://www.biochar-international.org/biochar/carbon).
The Biochar Carbon Offset Methodology quantifies the stable carbon component of biochar as well as the avoided emissions from feedstock that would otherwise undergo combustion or decomposition. Critical to the methodology is identification of a cost-effective, scientifically valid test to measure the stable carbon component of biochar when applied to soils. IBI led an effort to identify a test methodology to assess and quantify the stable carbon component of biochar–the Biochar Carbon Stability Test Method (available for download below). The objective of this Test is to measure the recalcitrant, stable component of carbon in biochar that will exhibit at least a 100-year residence time in soil (100 years being the pro forma definition of permanence in the Kyoto Protocol and applied to most other carbon exchange programs, including ACR).
To develop the Biochar Carbon Stability Test, IBI convened a group of world-class experts (the Expert Panel) in different fields of biochar relevant to stability and representing the research and commercial sectors. The goal was to identify a simple, yet reliable and verifiable measure for biochar stability. Important requisites were defined for the test, including cost, repeatability, and availability. The Biochar Carbon Stability Test Method agreed upon by the Expert Panel involves measurement of certain physico-chemical properties of the stable carbon in biochar that exhibits stability in soil for a minimum of a 100-year time span.
The full citation of the Test Method is below. To read the document, please click here.
Budai, A., Zimmerman, A. R., Cowie, A. L., Webber, J. B. W., Singh, B. P., Glaser, B., Masiello, C. A., Andersson, D., Shields, F., Lehmann, J., Camps Arbestain, M., Williams, M., Sohi, S. and Joseph, S. (2013). Biochar Carbon Stability Test Method: An assessment of methods to determine biochar carbon stability. International Biochar Initiative document; http://www.biochar-international.org/sites/default/files/IBI_Report_Bioc....
IBI wishes to thank the members of the Expert Panel, who voluntarily agreed to devote their time to this collective effort, for which we express our gratitude in the name of the global biochar community. The Members of the Expert Panel include: