Climate Change and Glacial Environments

Climate change is transforming glacial and periglacial environments at an unprecedented rate. Glaciers are retreating, ice sheets are losing mass, permafrost is thawing, and the consequences for sea levels, water resources, ecosystems, and human communities are profound. This lesson examines the evidence for change, the processes driving it, and the implications for the future.

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Evidence of Glacier Retreat

Global Trends

The evidence for global glacier retreat is overwhelming and comes from multiple independent sources:

• Direct measurement — stake surveys, GPS, and satellite altimetry show that the vast majority of the world's glaciers are retreating. The World Glacier Monitoring Service (WGMS) reports that the global average glacier has lost approximately 28 m of ice thickness since 1970.
• Satellite imagery — repeat photography and satellite monitoring (e.g., Landsat, Sentinel) document changes in glacier extent over decades.
• Mass balance measurements — continuous monitoring of accumulation and ablation on reference glaciers worldwide shows consistently negative mass balances since the 1980s.

Specific Glacier Case Studies