Fig. 2: Spatial land allocation for CDR deployment within climate refugia resilient to 1.8 °C.

The figures are based on the focus scenario SSP2-26 and show the results for an annual CO₂ removal of 6 GtCO₂. The remaining climate refugia at 1.8 °C are shown in grey in the left column. a–c, The spatially explicit (left column) and country-level (right column) allocation of climate refugia for CDR deployment is shown for the three model frameworks AIM (a), GLOBIOM (b) and IMAGE (c). Global warming of 1.8 °C roughly corresponds to the median peak warming of the focus scenario SSP2-26 across the five model frameworks and is therefore chosen as the warming level for climate refugia. The CDR land allocation in all maps in this figure corresponds to the CO₂ removal of 3 GtCO₂ via forestation (afforestation, reforestation and forest restoration) and 3 GtCO₂ via crop-based BECCS as this is the highest CO₂ removal level reached by both CDR options across all three model frameworks in SSP2-26, allowing for a consistent comparison across CDR options and models. GCAM and REMIND-MAgPIE were not considered for this analysis component as these two models do not report the required AR6 CO₂ removal data. The robustness of the results presented here is evaluated in the Supplementary Information. Information on CO₂ removal scaling and related land requirements is provided in the Supplementary Information. Basemaps were generated in Cartopy using Natural Earth data⁸⁹.