The effect of land-based mitigation technologies on the carbon cycle and climate

Carbon dioxide removal (CDR) strategies are critical to meet the Paris Agreement and, in addition to emission reductions, are key to reach the Sustainable Development Goals (SDGs). All current IPCC scenarios that achieve the Paris Agreement’s objectives rely on CDR, and implementing CDR into coupled Earth System Modelling systems will be key for CMIP7 scenario development and simulations. Here we present results from the LANDMARC project which aims to explore the efficiency of carbon dioxide removal as well as risks associated with land-based mitigation technologies (LMTs). We employ a coupled modeling system consisting of the EC-Earth3-CC Earth System Model with the LPJ-GUESS dynamic vegetation model, and the LandSHIFT-G land use model, and simulate six different LMTs, specifically i) fixing carbon in vegetation and soils by afforestation; increasing soil carbon by ii) no/reduced tillage agriculture and iii) combining fossil fuel substitution; medium to long-term storage of carbon by iv) bioenergy and carbon capture and storage (BECCS) and biochar as well as v) reducing deforestation through agro-forestry and agro-pastoral practices. Based on the simulations, we estimate the efficiency of the LMTs, and highlight regions with particularly high or low potential. We also present a brief assessment of potential risks associated with LMTs, analyzing global and regional impacts on simulated vegetation function and composition, and feedbacks with the atmosphere.