Comprehensive Earth system models (ESMs) are essential for gauging long-term carbon removal potentials and storage, for example, through biochar-mediated soils. They complement point information from experiments and field studies with regional-to-global scale assessments, and allow investigating biochar-carbon cycle interactions and sensitivities under a changing climate. However, the ESMs lack explicit accounting for biochar carbon pools and biochar-mediated turnover of soil organic carbon. We leverage our experience on modeling spatially explicit CDR to integrate these insights and core carbon cycle dynamics of BC-amended croplands into a comprehensive ESM. In addition, advances in understanding of geodiversity impacts on soil processes within the new Cluster of Excellence TERRA will yield new insights into carbon removal potential under future climate pathways. We establish the modeling framework, evaluate parameter sensitivities, and identify model parameterizations that bracket the uncertainties reported from lab and field experiments. Our modeling platform enables the integration of diverse biochar approaches to study their implications for global carbon removal efficacy.