Wang et al. (2026) The impact of 75 years of climate change on Mediterranean glacier mass balance

Identification

• Journal: Global and Planetary Change
• Year: 2026
• Date: 2026-02-09
• Authors: Bingdian Wang, Philip D. Hughes, Christopher M. Darvill, Jamie Woodward
• DOI: 10.1016/j.gloplacha.2026.105370

Research Groups

• Department of Geography, School of Environment, Education and Development, The University of Manchester, Manchester M13 9PL, UK.

Short Summary

This study investigates the impact of 75 years of climate change on Mediterranean glacier mass balance and snowpack dynamics, revealing a dominant control by rising summer temperatures and a limited influence of the North Atlantic Oscillation (NAO). It highlights that local topoclimatic factors, such as avalanching snow, are critical for the survival of the region's remaining small, warm-wet glaciers.

Objective

• To analyze how temperature and precipitation have varied regionally across the Mediterranean over the last 75 years.
• To determine the trends in snowpack and glacier dynamics in the Mediterranean region.
• To establish the relationship between climate change and glacier/snowpack changes.
• To assess the extent to which the North Atlantic Oscillation (NAO) influences glacier change in the Mediterranean.

Study Configuration

• Spatial Scale: The Mediterranean region, focusing on 20 research mountain areas (0.5° × 0.5° grid squares) categorized into five groups: The Western Mediterranean (High Atlas, Picos de Europa, Sierra Nevada, West Pyrenees, Central Pyrenees, East Pyrenees), The Central Mediterranean (Maritime Alps, Bernese Alps, Mount Cinto, Calderone, Julian Alps), The Balkans & Greece (Durmitor, Prokletje, Mount Olympus, Pirin Mountains), Western & Central Turkey (Uludağ, Mount Erciyes), and Eastern Turkey (Kaçkar Mountains, Mount Cilo, Mount Ararat). The study also included 20 glaciers from the Alps and 3 Mediterranean glaciers with mass balance records for comparison.
• Temporal Scale: Primarily the last 75 years (since 1950, up to 2024 for some climate data). Snow cover analysis covers 2001–2023.

Methodology and Data

• Models used:
  • Multiple Linear Regression Model: Used to calculate annual glacier mass balance based on monthly solid precipitation and mean air temperature, adapted from Marzeion et al. (2012a) and Marzeion and Nesje (2012).
  • Simple Degree Day Model (SDDM): Applied to simulate glacier melt for glaciers without historical mass balance data.
• Data sources:
  • Climate Reanalysis: ERA5-Land (0.1° × 0.1° resolution) and ERA5 (0.25° × 0.25° resolution) datasets for temperature and precipitation (since 1940/1950).
  • Meteorological Stations: Data from stations in Switzerland and Andorra for validating ERA5-Land data and determining regional temperature and precipitation lapse rates.
  • Snow Cover: MODIS Terra CGF (Cloud-Gap-Filled) Snow Cover Daily L3 Global 500 m SIN Grid (MOD10A1F) dataset (2000–present).
  • Glacier Mass Balance: World Glacier Monitoring Service (WGMS) Fluctuations of Glaciers (FoG) Database for observed annual, summer, and winter mass balance data, and Equilibrium Line Altitude (ELA) data.
  • Atmospheric Oscillation: North Atlantic Oscillation (NAO) index data from NOAA CPC.
  • Topographic Data: ETOPO 2022 Global Relief Model (15 arc-second resolution) for bedrock elevation.
  • Glacier Inventory: Randolph Glacier Inventory (RGI) 7.0 for glacier classification.

Main Results

• Summer temperatures in the Mediterranean region have increased significantly since 1976, with an average rise of >1.9 °C by 2024 relative to the 1991–2020 mean, and multiple extreme heat events recorded (e.g., 2003, 2012, 2024).
• Winter precipitation in the Mediterranean has shown a statistically significant slight declining trend over the last 75 years, with considerable interannual and regional fluctuations.
• Snow cover duration generally declined across most of the Mediterranean from 2019 to 2023 compared to the 2001–2023 baseline, with exceptions in the central Iberian Peninsula and eastern Alps attributed to extreme snowfall events.
• Temperature is a more significant driver of snow cover area variations than precipitation in most Mediterranean regions, though precipitation plays a comparable or stronger role in parts of the Western & Central Mediterranean (e.g., High Atlas, Pyrenees, Maritime Alps).
• The North Atlantic Oscillation (NAO) has a limited influence on Mediterranean glacier mass balance and snowpack, with R² values for snow cover area below 0.30 and for winter mass balance around 0.03, indicating a weaker relationship compared to glaciers further north in Europe.
• Mediterranean glaciers (e.g., Calderone, Maladeta, Ossoue) exhibit an overall negative annual mass balance trend over the past 75 years, with summer temperature being the dominant climatic control.
• Local topoclimatic factors, such as excess snow accumulation from avalanching and windblown snow, are crucial for the survival of small Mediterranean glaciers (e.g., Debeli Namet, Mount Cilo), estimated to contribute around 150% of the measured annual precipitation.
• Warm-wet glaciers, characteristic of the Mediterranean, are found to be more sensitive to changing temperatures than cold-dry glaciers.

Contributions

• Provides the first comprehensive, long-term (75-year) analysis of climate change impacts on glacier mass balance and snowpack dynamics across the entire Mediterranean region, filling a significant knowledge gap compared to more studied regions like the Alps or Scandinavia.
• Quantifies the dominant role of summer temperature in Mediterranean glacier retreat and highlights the critical, region-specific importance of local topoclimatic factors (e.g., avalanching snow) for glacier survival.
• Offers valuable insights for water resource management in the Mediterranean and serves as an important comparative study for other mid-latitude mountain regions globally, such as the Tibetan Plateau and the American Cordillera.
• Demonstrates the higher sensitivity of warm-wet Mediterranean glaciers to temperature changes, aligning with global observations.

Funding

Not explicitly stated in the provided text.

Citation

@article{Wang2026impact,
  author = {Wang, Bingdian and Hughes, Philip D. and Darvill, Christopher M. and Woodward, Jamie},
  title = {The impact of 75 years of climate change on Mediterranean glacier mass balance},
  journal = {Global and Planetary Change},
  year = {2026},
  doi = {10.1016/j.gloplacha.2026.105370},
  url = {https://doi.org/10.1016/j.gloplacha.2026.105370}
}