Corresponding system configurations are shown for all cases shown in Fig. 3. The four levels of net negative CO2 emissions to be achieved by the end of the century are for identification purposes only and are not visible on this figure as they will only be achieved after the point of reaching net zero CO2 emissions. In the cases selected here, net zero CO2 emissions are reached in 2050. Five illustrative system variations are shown per level (labelled A–E, defined in Extended Data Tables 3, 4). NA, scenarios did not solve under the imposed CDR and bioenergy constraints (Extended Data Table 4). Fossil fuel and industry CCS contributions (white hatched areas) represent CO2 that is generated but not emitted to the atmosphere. Net negative CO2 emissions are the sum of gross positive CO2 emissions from energy and industrial sources and gross positive land-use CO2 emissions, and are zero by design in this time step. Gross negative CO2 emissions comprise gross negative land-use CO2 emissions and CDR through BECCS. The combined size of all bars per scenario gives an indication of the overall size of the remaining CO2 producing system by the end of the century. Because the timing of CDR upscaling and amount of CDR at the time of reaching global net zero CO2 emissions was not explicitly varied in the set of illustrative scenarios developed for this study, it would be wrong to interpret the narrow degree of variation and general agreement across scenarios as a robust feature. Variations could be explored through additional dedicated studies (Extended Data Table 2).