Mitigating trade-offs between global food access and net-zero emissions: the potential contribution of direct air carbon capture and storage

"Net-zero greenhouse gas emissions in the second half of this century" affirmed by the Paris Agreement is one of humankind's common targets. Many scenario analyses suggest that negative emission technologies (NETs), such as bioenergy with carbon capture and storage and afforestation, are required to achieve this target, but their large-scale deployment has a trade-off relationship with food security. We considered an innovative NET, direct air carbon capture and storage (DACCS), and analyzed its impact on global food access based on an indicator defined by food expenditure per GDP. We found that the scenario considering DACCS mitigates the adverse impact on food access in regions such as Sub-Saharan Africa compared to the scenario not considering DACCS by alleviating food expenditure increase and GDP loss associated with emission reduction efforts. In the former scenario, DACCS becomes a mainstream NET instead of bioenergy with carbon capture and storage, mitigating the food price increases associated with land use intensification. Furthermore, the implementation of DACCS allows the use of gas and oil without CCS in regions and sectors where emission reduction is difficult, contributing to the mitigation of the GDP loss associated with emission reduction. DACCS may be evaluated as a worthful option to pursue the simultaneous achievement of net-zero emissions and favorable food access.