Fig. 1: Impact of model differences, climate targets and other scenario assumptions on the projections of electricity generation sources.

a, Scenario spread in sources of electricity generation (secondary energy) is attributed to three drivers, depicted in the three corners: model differences, climate targets and other scenario assumptions. For example, fossil fuel use (red) being in the top corner indicates that the climate target dominates the scenario spread projected in fossil fuel use and that it is less affected by model differences and other scenario assumptions. Analogously, variables can instead be dominated by model differences (bottom left) or other scenario assumptions (bottom right). Dashed lines mark the 50% values in each of these three axes. The three main categories of sources of electricity generation are indicated using different colours: fossil fuels without CCS (red), sources involving CCS (blue), and renewables, including biomass (green). The totals in each category are shown with large dots marking the years 2030, 2050 and 2100. Individual carriers or technologies in each category are shown with smaller dots and are annotated in the figure (in analogous colouring, and with 2030 shown using a black border). b–g, Projected 2050 values of individual sources of electricity generation, split by model (where models are identified by the three-letter abbreviations, defined in Extended Data Table 2) or climate category, based on the dominant driver (that is, we do not analyse other scenario assumptions in these subpanels): solar energy (b), hydroenergy (c), biomass with CCS (d), gas with CCS (e), gas without CCS (f) and coal without CCS (g). In box plots, centre line is the median, boxes the interquartile range, and whiskers the minimum and maximum values within ±1.5 times the interquartile range; a total of 1,152 individual scenario entries are shown in dots. The same figure using fractions of the total electricity generation (instead of absolute values) is shown in Extended Data Fig. 4.