Biochar (usually classified as a geoengineering option) is charcoal produced through the thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen. The process has been touted by some proponents as a potentially important component of climate policymaking over the course of this century. Because biochar can sequester carbon in soil for hundreds to thousands of years, supporters argue that it constitutes a “carbon negative” process:
Ordinary biomass fuels are carbon neutral — the carbon captured in the biomass by photosynthesis would have eventually returned to the atmosphere through natural processes — burning plants for energy just speeds it up. Sustainable biochar systems can be carbon negative because they hold a substantial portion of the carbon in soil … (International Biochar Institute)
Biochar has been fulsomely characterized by climate activist Bill McKibben as “the key to the New Carbon Economy,” and received prominent coverage in the Working Group III report of the IPCC’s Fifth Assessment Report as one of the technologies that could effectuate negative emissions scenarios that might be critical to avoiding the passing of critical temperature thresholds. However, an article by Melissa Leach, James Fairhead and James Fraser in 2012 in the Journal of Peasant Studies (subscription required) sounds a cautionary note in terms of potential implications of a full-scale commitment to biochar for farmers, with a focus on Africa. It would be an excellent reading in a module on climate geoengineering, or one discussing equity and human rights issues associated with climate policy responses.
Among the conclusions of the article:
- Analyses that contemplate large draw downs of carbon from biochar (e.g. one study projecting a potential sink of 5.5-9.5 GtC/year by 2100) “suppose an enormous growth in the resources and land areas devoted to the production of biochar feedstocks . . .” Some advocates have proposed dedicating somewhere between 200 million-1 billion hectares of forests, savannah and croplands to biochar projects. Such opponents have invoked the specter of large-scale “land grabbing” that they contend could threaten agricultural, pastoralist, collecting and other livelihoods;
- Foreign deals for biochar feedstock land could ultimately result in competition between biofuels and biochar projects;
- While some have argued that small farmers in developing countries could develop a substantial new income stream from sequestering carbon in biochar systems, many proponents of biochar as a climate solution are advocating development of new technologies to produce “clean char” that are different than indigenous practices in this context. Moreover, in contrast to REDD+, very little attention has been devoted to ascertaining how farmers could financially benefit from biochar projects;
- “The logic of the market” is likely to gravitate against small-scale projects that conducive to local priorities and livelihoods;” the need for verification and standardization protocols are likely to lead to large-scale industrialized biochar projects.
In contrast to the rather dry rendition of the potential socio-economic threats posed by biochar projects in the IPCC’s Fifth Assessment Report, this article is a stark reminder of how such projects pose the threat of exacerbation of existing inequalities associated with climate change. Moreover, while some proponents of carbon dioxide removal approaches argue that they are more benign than solar radiation management approaches because they allegedly don’t threaten transboundary impacts, this article is a palpable reminder that this is not necessarily the case.