Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes

TLDR

Earth’s ice sheets are melting, raising sea levels, and understanding the climate processes driving mass loss is essential. The study used ICESat and ICESat‑2 satellite laser altimetry to estimate grounded and floating ice mass change in Greenland and Antarctica from 2003 to 2019. Grounded‑ice loss averaged ~320 Gt yr⁻¹, contributing 14 mm of sea‑level rise, with regional variations driven by ice flow, melting, and precipitation. Smith et al., Science, this issue p.

Abstract

Taking stock of our losses Earth's ice sheets are melting and sea levels are rising, so it behooves us to understand better which climate processes are responsible for how much of the mass loss. Smith et al. estimated grounded and floating ice mass change for the Greenland and Antarctic ice sheets from 2003 to 2019 using satellite laser altimetry data from NASA's ICESat and ICESat-2 satellites. They show how changing ice flow, melting, and precipitation affect different regions of ice and estimate that grounded-ice loss averaged close to 320 gigatons per year over that period and contributed 14 millimeters to sea level rise. Science , this issue p. 1239