Over the past several decades, the rapid melting of mountain glaicers has been a primary contributor to rising sea levels. Estimates of the long-term contribution of non-polar glacial melting to sea level rise vary substantially, but most experts agree that the contribution will fall somewhere between a tenth and a third of a meter. A recent Nature Geoscience report used the World Glacier Inventory, a repository of information on >120,000 glaciers, to predict changes this century in all 19 non-polar regions containing mountain glaciers and ice caps. This study predicts that total glacial volume will reduce by 21 +/- 6% by 2100, though in certain areas the reduction may be as high as 75%. This will lead to dramatic changes in regional hydrology and serious water problems for people who depend on seasonal glacial melting for freshwater and irrigation (see my December post, “Fog harvesting for a thirstier world”).
Water shortages, sea level rise, and erosion and hydrologic changes resulting from mountain glacial melting all pose real and very apparent problems for human populations. Another fascinating result of glacial melting will not incite new environmental dangers, but is already leading to social unrest and conflict between scientists and indigenous populations. It turns out that in certain regions, tombs, bodies and ruins from ancient civilizations, once buried deep beneath the ice, are now thawing. The most prominent example of this is in the Central Asian Altai mountains, where over 700 tombs have been preserved for 2,500 years by ice or permafrost. Increasing ground surface temperatures are causing these tombs to thaw. Another example is the huge coastal cemetery near Barrow, Alaska, where sea ice loss is causing the coastline to erode at rates of up to 20 m/year, exposing generations of human remains. It is becoming apparent that glacial thawing will impact frozen archaeology worldwide, and will potentially lead to both great discoveries and great unrest.
Globally, some of the most fascinating human archaelogical discoveries have involved frozen remains. Freezing allows preservation of human tissue that would otherwise decay in several decades, and archaelogists are now using advanced molecular techniques to date such tissue and even extract ancient DNA samples. Archaeologists across the world are now clamoring to take advantage of newley exposed human remains that may only be valuable for a short period of time. This has already stirred anger amongst many indigenous populations, who do not wish to see their ancestor’s remains and a part of their cultural heritage uprooted and shipped off to a lab thousands of miles away for chemical analysis.
The problem essentially arises from the fact that there is currently no standard legal framework to mediate the interests of scientists, governments and indigenous people with respect to these precious archaeological repositories. Glacial retreat necessitates the creation of new laws and policies to address these concerns- and soon, if our mountain melting rate predictions are at all accurate.
Radick and Hock. 2011. Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise. Nature Geoscience. In press.
Molyneaux and Reay 2011. Frozen archaeology meltdown. Correspondence . Nature Geoscience. In press.