In their paper, published in Proceedings of the
Glaciers cover close to 10% of the Earth's land surface but are shrinking rapidly across most parts of the world. The area of land occupied by glaciers will decrease significantly by the end of the present century. The largest individual contributions to global glacier mass loss come from the glaciers of the Gulf of Alaska, the Canadian Arctic, and the ice sheet peripheries of Greenland and Antarctica.
However, the glaciers with the most negative mass balances are located in the European Alps and at low latitudes in the South American Andes. In the European Alps, atmospheric warming has been pronounced in the last 30 years, especially during the summer months, which when combined with decreased snowfall, has led to a 54% loss of ice area since 1850. Current projections suggest that just 4-13% of the 2003 European Alps ice area will remain by 2100.
The changes in river hydrology and morphology due to climate-induced glacier loss are projected to be the greatest of any hydrological system. There will be significant changes to flow regimes in glacierised watersheds, with a shift to greater stochasticity as glacial runoff decreases and flow becomes more dependent on unpredictable precipitation events and snow melt. Glacier shrinkage will alter sediment transport, and biogeochemical and contaminant fluxes from rivers to oceans.
An unexpected impact of glacier shrinkage is the liberation of contaminants including emission products from industrial activity, such as black carbon and associated compounds, mercury, pesticides, and other persistent organic pollutants. There is uncertainty in the release of these legacy contaminants from glacierised areas, though their transport to downstream systems by meltwater will eventually reduce as glacial ice volume shrinks.
