Geology topics
Publications and source records attributed to Matthias Huss.
Glaciers lost 408 ± 132 Gt of mass during the hydrological year 2025, equivalent to 1.1 ± 0.4 mm sea-level rise. Since 1975, glacier mass loss has totalled 9,583 ± 1,211 Gt, equivalent to 26.4 ± 3.3 mm of sea-level rise, with six of the highest mass-loss years on record occurring in the past seven years.
Over the period 2021–2024, glaciers in Western Canada and the conterminous US (WCAN-US), and Switzerland respectively lost mass at rates of 22.2 ± 9.0 and 1.5 ± 0.3 Gt yr −1 representing a twofold increase in mass loss compared to the period 2010–2020. Since 2020, total ice volume was depleted by 12% (WCAN-US) and 13% (Switzerland). Meteorological conditions that favored high rates of mass loss included low winter snow accumulation, early-season heat waves, and prolonged warm, dry conditions. High transient snow lines, and impurity loading due to wildfires (WCAN-US) or Saharan dust (Switzerland) darkened glaciers and thereby increased mass loss via greater absorbed shortwave radiation available for melt. This ice-albedo feedback will lead to continued high rates of thinning unless recently exposed dark ice and firn at high elevations is buried by seasonal snowfall. Physical models that simulate impurity deposition and movement through firn and ice are needed to improve future projections of glacier mass change.
Glaciers are indicators of ongoing anthropogenic climate change 1 . Their melting leads to increased local geohazards 2 , and impacts marine 3 and terrestrial 4 , 5 ecosystems, regional freshwater resources 6 , and both global water and energy cycles 7 , 8 . Together with the Greenland and Antarctic ice sheets, glaciers are essential drivers of present 9 , 10 and future 11 , 12 , 13 sea-level rise. Previous assessments of global glacier mass changes have been hampered by spatial and temporal limitations and the heterogeneity of existing data series 14 , 15 , 16 . Here we show in an intercomparison exercise that glaciers worldwide lost 273 ± 16 gigatonnes in mass annually from 2000 to 2023, with an increase of 36 ± 10% from the first (2000–2011) to the second (2012–2023) half of the period. Since 2000, glaciers have lost between 2% and 39% of their ice regionally and about 5% globally. Glacier mass loss is about 18% larger than the loss from the Greenland Ice Sheet and more than twice that from the Antarctic Ice Sheet 17 . Our results arise from a scientific community effort to collect, homogenize, combine and analyse glacier mass changes from in situ and remote-sensing observations. Although our estimates are in agreement with findings from previous assessments 14 , 15 , 16 at a global scale, we found some large regional deviations owing to systematic differences among observation methods. Our results provide a refined baseline for better understanding observational differences and for calibrating model ensembles 12 , 16 , 18 , which will help to narrow projection uncertainty for the twenty-first century 11 , 12 , 18 .