Potential of land-based climate change mitigation strategies on abandoned cropland

Natural revegetation, afforestation, and lignocellulosic crops for bioenergy, possibly coupled with a developing technology like carbon capture and storage, are the most common land-based climate change mitigation options. However, they can compete for land and threaten food security or nature conservation. Using abandoned cropland for their deployment can minimize these risks, but associated potentials are unclear. Here, we compare alternative land-based mitigation options by integrating historical and future (up to 2050) abandoned cropland with site-specific biomass yields and life-cycle emissions. Considering natural revegetation in biodiversity priority areas and different measures in the remaining land can achieve a mitigation potential of 0.8–4.0 GtCO2-equivalents yr−1 (2–11% of 2021 global CO2 emissions). Afforestation generally provides larger climate benefits than bioenergy, but bioenergy with carbon capture and storage delivers the highest mitigation in most locations. Overall, these results offer refined estimates of mitigation potentials from abandoned cropland and highlight opportunities for context-specific mitigation measures.