Potential of Land‐Neutral Negative Emissions Through Biochar Sequestration

Abstract

Negative emissions (NE) are under discussion as elements of mitigation strategies aiming to achieve the climate targets of the Paris Agreement. However, biomass‐based NE technologies such as bioenergy with carbon capture and storage (BECCS) require vast land areas in order to meet the targets projected by climate economic optimization models, thereby competing with food production and ecosystem protection. Here we assess feasible NE contributions of alternative, more sustainable pyrogenic carbon capture and storage (PyCCS) based on land‐neutral biomass production using biochar‐mediated yield increases to maintain calorie production while realizing net CO2 extraction from the atmosphere. Simulations with a biosphere model indicate that such a land‐ and calorie‐neutral PyCCS approach could sequester 0.44–2.62 Gt CO2 yr−1 depending on the assumed biochar‐mediated yield increase achievable on (sub‐)tropical cropland (15%, 20% and 30%, respectively). Cumulatively, by the end of the century, 33–201 Gt CO2 could be sustainably supplied by such an approach, equaling 6%–35% of the NE demand projected for trajectories likely to limit climate warming to 2°C or lower. Furthermore, additional areas dedicated to BECCS in integrated assessment scenarios could instead be used to increase global calorie production (by 2%–16%), or spared for nature protection (up to ∼ 100 Mha). Thus, land‐ and calorie‐neutral PyCCS may, within limits, contribute to lessening the additional land use pressure of biomass‐based NE technologies.

Developing a Sustainability Vision for the Global Wine Industry

“…The primary "removal" is carried out by photosynthesis while pyrolysis slows down the return to the atmosphere. Pyrolysis with carbon capture and storage (PyCCS, in biochar) has cobenefits for food and fiber production ([101] and metastudies therein); yield improvements have particularly been found in subtropical and tropical soils which could make this form of CDR land-neutral [102]. Adding biochar to organic waste treatment such as composting can reduce gaseous N emissions [103,104].…”

Biochar from animal manure: A critical assessment on technical feasibility, economic viability, and ecological impact

“…Pyrogenic carbon capture and storage, which includes the production and pyrolysis of biomass and the application of biochar to soils and materials, has been identified as one of the most promising negative emission technologies (Smith et al, 2019;Werner et al, 2018Werner et al, , 2022. To establish a carbon sink, CO 2 must be removed from the atmosphere, transformed into a stable form, and stored for a verifiable long time.…”

Research to Industry and Industry to Research

“…In fact, the storage of carbon is successful in the long term, i.e., it is not released into the air as CO 2 . Therefore, in the case of biogenic feedstock, it is removed from the atmosphere, achieving a "negative emission" (Werner et al, 2022).…”

“…V reiro et al 2018;Werner et al 2022) or as biochar-functionalized materials in other sectors. The risk of heavy metal contamination in soils and their potential transfer to the food chain may also be reduced following conversion to biochar, which makes it safer for land application (Marchuk et al, 2021).…”