Mass Loss of Greenland and Antarctic Peripheral Glaciers From ICESat and ICESat-2

Greenland and Antarctica's peripheral glaciers are an important but often overlooked element in the global sea-level rise budget. Here, we use satellite laser altimetry from ICESat and ICESat-2 to assess the mass loss from Greenland's and Antarctica's peripheral glaciers for three periods: February 2003 to October 2009, October 2009 to April 2018, and October 2018 to April 2023. Over these periods, Greenland's peripheral glacier mass loss has increased from 27.3 ± 7.9 Gt yr⁻¹ during 2003–2009, to 35.8 ± 5.3 Gt yr⁻¹ during 2018–2023. The ice loss from Antarctica's peripheral glaciers underwent a more complex change during this time, with a mass loss −4.2 ± 1.3 Gt yr⁻¹ during 2003–2009, sharply rising to −16.0 ± 5.9 Gt yr⁻¹ during 2009–2018, and subsequently declining to −9.0 ± 0.7 Gt yr⁻¹ during 2018–2023. This temporal pattern of mass loss is observed across all Antarctic regions. Notably, the Antarctic Peninsula experienced a mass loss of 2.6 ± 3.1 Gt yr⁻¹ during 2003–2009 followed by gains of 2.7 ± 3.8 Gt yr⁻¹ and 11.9 ± 1.7 Gt yr⁻¹ during 2009–2018 and 2018–2023, respectively. This shift toward mass gain during 2018–2023 can be attributed to exceptional levels of precipitation during the winters of 2019 and 2020. We conclude that increased snowfall played a crucial role in mitigating glacier mass loss during this later period. Overall, our findings show accelerating mass loss of Greenland and Antarctica's peripheral glaciers with complex variability, both spatially and temporally, with certain regions experiencing mass gains through increased snowfall.