Biochar as multi-purpose sustainable technology: experiences from projects in Tanzania

摘要

Biochar was recently included as a promising negative emissions technology (NET) in the Special Report on Global Warming of 1.5 degrees C published by the Intergovernmental Panel on Climate Change. Unlike other NETs, it can potentially be used to mitigate global climate change while adding to local resilience in countries highly exposed and sensitive to impacts of climate change, such as least-developed countries (LDCs). The study is as an empirical contribution to the, as of yet, underdeveloped literature on deployment of negative emissions technologies in LDCs in general and on biochar use in developing countries and LDCs specifically. Nine historical and existing biochar projects in Tanzania are mapped in order to analyse problems, goals and common trade-offs associated with small- to medium-scale biochar production in LDCs. The mapping is based on a literature and document study, interviews with project actors, and on-site visits to biochar projects during 2019. The paper gives support to the observation made in the biochar literature that while biochar has many potential socio-economic and environmental benefits, combining them in one single project is difficult. It is concluded that implementing biochar projects in Tanzania will likely involve trade-offs between the development and subsistence strategies and needs of local communities, the motivational forces of different project participants, and the uneven regulatory capacity of the state. We end by reflecting on the use of biochar projects to offset carbon emissions made elsewhere.