Fig. 1. GrIS SMB under low and high-end warming by 2100.

a Downscaled GrIS surface mass balance (SMB) from CESM2-forced RACMO2.3p2 at 1 km under SSP5-8.5 in 2080–2099. Black contour and hatching outline the equilibrium line altitude (ELA; SMB = 0) for the historical period 1950–1990 and for SSP1-2.6 in 2080–2099 respectively. The GrIS is divided in seven sectors⁷ including north (NO), northwest (NW), northeast (NE), central west (CW), central east (CE), southwest (SW) and southeast (SE). b Time series of GrIS area fraction situated in the ablation zone (SMB $<$ 0) from CESM2-forced RACMO2.3p2 for the historical period (1950–2014), SSP1-2.6 and SSP5-8.5 (2015–2099) scenarios. The coloured bands in b span the minimum and maximum ablation zone fraction of individual GrIS sectors. c and d Time series of GrIS integrated SMB and components including runoff, total precipitation including snowfall and rainfall, melt and refreezing for the period 1950–2099 under SSP1-2.6 and SSP5-8.5 respectively. Linear and quadratic fits are represented as coloured dashed curves. The black line in b and green lines in c, d represent the RACMO2.3p2 simulation forced by ERA reanalyses (1958–2020)¹⁰.