Glacier preservation doubled by limiting warming to 1.5°C versus 2.7°C.

Abstract

Glaciers adapt slowly to changing climatic conditions, with long-term implications for sea-level rise and water supply. Using eight glacier models, we simulated global glacier evolution over multicentennial timescales, allowing glaciers to equilibrate with climate under various constant global temperature scenarios. We estimate that glaciers globally will lose 39 (range, 15 to 55)% of their mass relative to 2020, corresponding to a global mean sea-level rise of 113 (range, 43 to 204) mm even if temperatures stabilized at present-day conditions. Under the +1.5°C Paris Agreement goal, more than twice as much global glacier mass remains at equilibration (53% versus 24%) compared with the warming level resulting from current policies (+2.7°C by 2100 above preindustrial). Our findings stress the need for stringent mitigation policies to ensure the long-term preservation of glaciers.