Fig. 1: GHG emissions allocations across various fairness principles.
From: Navigating the black box of fair national emissions targets
a, Global emissions trajectories for various temperature targets and historical and baseline emissions pathways (in Gt CO2-equivalents). 2030 reduction percentages with respect to 2021 are indicated (Supplementary Information D). b, Principle that allocates most to the country (dots, sized by population) indicated in colours, with historical emissions per capita on the vertical and GDP per capita on the horizontal (logarithmic axes). Only countries with more than 1 million inhabitants are shown. c,d, Emissions allocations over time (c) and for 2030 only (d) across a variety of allocation rules (see Table 2), with respect to 2021 emissions (= 1) for comparison. Markers and lines are based on default assumptions (1.6 °C, 50% chance, Supplementary Table 4), areas indicate distribution of estimates based on varying parameters. Upper and lower bounds of NDC emissions estimates are shown in c,d in green; fair allocations below NDCs indicate a combination of NDC ambition increase and foreign mitigation investment. Bold lines are based on default values (Supplementary Table 4), and shaded areas indicate minimum and maximum allocations across all global parameters (in a, for climate sensitivity only 50–67%) or allocation rule parameters (in c,d, convergence year only 2050–2080).
