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Biochar was recently included as a promising negative emissions technology (NET) in the Special Report on Global Warming of 1.5 °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. [ABSTRACT FROM AUTHOR]

Most mitigation scenarios compatible with a likely change of holding global warming well below 2 °C rely on negative emissions technologies (NETs). According to the integrated assessment models (IAMs) used to produce mitigation scenarios for the IPCC reports, the NET with the greatest potential to achieve negative emissions is bioenergy with carbon capture and storage (BECCS). Crucial questions arise about where the enormous quantities of biomass needed according to the IAM scenarios could feasibly be produced in a sustainable manner. Africa is attractive in the context of BECCS because of large areas that could contribute biomass energy and indications of substantial underground CO2 storage capacities. However, estimates of large biomass availability in Africa are usually based on highly aggregated datasets, and only a few studies explore future challenges or barriers for BECCS in any detail. Based on previous research and literature, this paper analyses the pre-conditions for BECCS in Tanzania by studying what we argue are the applications of BECCS, or the components of the BECCS chain, that are most feasible in the country, namely (1) as applied to domestic sugarcane-based energy production (bioethanol), and (2) with Tanzania in a producer and re-growth role in an international BECCS chain, supplying biomass or biofuels for export to developed countries. The review reveals that a prerequisite for both options is either the existence of a functional market for emissions trading and selling, making negative emissions a viable commercial investment, or sustained investment through aid programmes. Also, historically, an important barrier to the development of production capacity of liquid biofuels for export purposes has been given by ethical dilemmas following in the wake of demand for land to facilitate production of biomass, such as sugarcane and jatropha. In these cases, conflicts over access to land and mismanagement have been more of a rule than an exception. Increased production volumes of solid biomass for export to operations that demand bioenergy, be it with or without a CCS component, is likely to give rise to similar conflicts. While BECCS may well play an important role in reducing emissions in countries with high capacity to act combined with existing large point sources of biogenic CO2 emissions, it seems prudent to proceed with utmost caution when implicating BECCS deployment in least developed countries, like Tanzania.The paper argues that negative BECCS-related emissions from Tanzania should not be assumed in global climate mitigation scenarios. [ABSTRACT FROM AUTHOR]

Biochar may contribute to both agricultural productivity and atmospheric carbon dioxide removal. However, despite the many potential upsides of adding biochar to amend carbon-depleted soils in sub-Saharan Africa, deployment is largely lacking. This paper explores the socio-economic factors that can explain tendencies to avoid action. Based on a survey of 172 farming households, key informant interviews, and focus group discussions in the Mbeya and Songwe regions of Tanzania, which were targeted for a biochar aid program in 2014, several socio-economic drivers behind the continued use of biochar deployment were identified in this follow-up study. A key deployment driver was the increased crop yields, perceived to be the result of adding biochar to soils, increasing yields from 1 metric ton per hectare to 3 metric tons per hectare. Food security and family income were cited as the main reasons to engage in biochar production and use. Climate change mitigation and increased resilience were other key reasons that motivated adoption. In terms of socio-economic factors, farmers with low education and income, the majority being males aged 40–60 years, contributed to low adoption rates in the study area. Respondents often cited the alternative usage of biochar feedstocks, lack of government involvement or extension services, traditions, and farming customs as the main constraints limiting biochar deployment. [ABSTRACT FROM AUTHOR]