Glacial retreat

Glacial Retreat Melting polar icecaps are a serious problem but it starts much closer to home. From the French Alps to the Rockies to the Andes, glaciers are retreating at alarming rates. 1931 1898 Sir Donald/ Perley Rock Trail Great Glacier Trall The photo above was taken in Great Glacier National Park by Dr Dan McCarthy of Brock University. We got it from www.nichols.edu/departments/glacier/glacier_retreat.htm. The white lines show historical glacier extents. Nichols University also shows this photo, from the Parks Canada Collection. It's the same shot, taken around 1898. In Europe the images are similar. On the left, there's an old postcard of Maladeta Glacier in the Pyrenees, and a photo taken in 2005. Smaller glaciers are worst affected. Some, like Bolivia's Chacaltaya Glacier, have vanished completely. BALBERTRAND - ALTA VALLE SUSA SHIACCIAIOE LASO GALAMA According to World Glacier Monitoring Service data from 2000 to 2005, the vast majority of monitored glaciers are in retreat. Ratios for four sets of European glaciers are given below. Italy: 50/53 Switzerland: 115/115 France: 7/7 Italy: 115/115 Glacial growth and shrinkage is usually measured in mm we (milimetres water equivalent). This is the thickness lost, expressed as a water volume. Other WGMS data shows that losses are accelerating over time. -2000 -4000 -6000 -8000 30 'reference' giaciers --- subset of 'reference glaciers -10000 --- all glaciers -12000 14000 1980 1985 1990 1995 2000 2005 2010 time lyears] A global problem Iceland USA The chart to the right shows average glacier mass losses (in mm we) for six countries and one continent. There isn't much good news but some areas, like the Ecrins in France, are very badly affected. France Canada Peru Antarctica According to the BBC, total ice- covered area in the Mont Blanc area Austria has fallen by more than 25% since 1970. -2600 -1800 - 1000 -200 2010s: 275 square kilmetres 1970s: 375 square kilometres So, what are we losing, apart from glaciers? Spring and summer meltwater from glaciers is used to generate hydroelectric power. It provides crucial water for crop irrigation. If the glaciers go, so does the water, the sustainable power source, and the crops. Fish and ther species that rely on Alpine ver systems will inevitably suffer. As the glaciers are melting, their valleys are becoming increasingly stable. Loose rock has caused the closure of popular tourist attractions in Switzerland and there are concerns that the combination of unstable rock and meltwater could cause 'dam bursts', endangering communities in Alpine valleys. Many of those communities rely on tourism. The popular Bossons Glacier above Chamonix has retreated about 1.2 kilometres since Victorian visitors enjoyed the views. What can we do? Glacial retreat is a symptom of climate change. There is no easy fix. If we do nothing the global climate continues down the path it's on now, the glaciers will continue to shrink. "In the worst-case scenario, by the end of the century glaciers in the Alps will be reduced to 5-10% of what we have now" -Michael Zemp, World Glacier Monitoring Service Piktochart cumulative mean annual mass balance (mm w.e.]