Projecting the response of Greenland's peripheral glaciers to future climate change: glacier losses, sea level impact, freshwater contributions, and peak water timing

Abstract. Greenland's peripheral glaciers are significant contributors to sea level rise and freshwater fluxes, yet their future evolution remains poorly constrained. This study projects the response of these glaciers to future climate change using the Open Global Glacier Model (OGGM) forced by CMIP6 climate data under four emission scenarios. By 2100, the glaciers are projected to lose 19 ± 6 % (SSP126) to 44 ± 15 % (SSP585) of their area and 29 ± 6 % (SSP126) to 52 ± 14 % (SSP585) of their volume (ensemble mean ± 1 SD across 10 GCMs), contributing 10 ± 2 to 19 ± 5 mm to sea level rise. Solid ice discharge is projected to decrease, while liquid freshwater runoff will peak within the 21st century. The runoff composition is projected to change drastically, with shares of glacier ablation decreasing from 92 % in 2021–2030 to 72 % by 2091–2100 and shares of rainfall and snowmelt increasing 8-fold and 15-fold, respectively, suggesting a shift in the hydrological regime. Timing of the maximum runoff varies across scenarios (2050 ± 21 for SSP126; 2082 ± 9 for SSP585) and subregions, with the projected maximum runoff reaching 214–293 Gt yr−1, implying significantly increased future freshwater fluxes. These changes will impact fjord water characteristics and coastal hydrography, and potentially influence larger ocean circulation patterns.