A regional assessment of land-based carbon mitigation options: Bioenergy, reforestation, forest management

Current scenarios assume that in addition to a rapid reduction in greenhouse gas emissions, land-based carbon mitigation will also be necessary to achieve the targets of the Paris Climate Agreement. Possible measures are increased carbon sequestration via planting new forests, the cultivation of bioenergy crops, possibly in combination with carbon capture and storage (BECCS), or increasing the carbon storage of existing forests. However, currently available scenarios that are in line with IPCC storylines (SSPs, Shared Socioeconomic Pathways and RCPs, Representative Concentration Pathways) usually have  a global  perspective, while in practice mitigation projects have to be realized regionally or locally. Here, we investigate the carbon mitigation potential via alternative management of Bavarian ecosystems using an ecosystem model with an explicit representation of climate impacts and land management. Bioenergy cultivation on existing agricultural land has a larger mitigation potential than reforestation only if combined with carbon capture and storage (BECCS).  The mitigation potential in the forestry sector via alternative management is limited (converting coniferous into mixed forests, nitrogen fertilization) or even negative (suspending wood harvest) due to decreased carbon storage in product pools and associated substitution effects. Overall, the potential for land-based mitigation in Bavaria is limited because the majority of current agricultural lands will still be needed for food production and the forestry sector offers only small per-area carbon mitigation potentials.