Glacier Ablation
Another consequence of global warming is glacier ablation, which is (in simpler words) the retreating of glaciers. There are 2 types of glacier which are retreating: ice sheets and valley glaciers. The difference between these 2 types are that ice sheets cover a whole land mass whereas valley glaciers only cover a small river valley. Ice sheets that are retreating are Greenland and Antarctica whereas valley glaciers that are retreating are the Jungfrau glacier ( Switzerland) and the Rhone glacier (France). They are retreating because less ice is added to the glacier than is melting from the glacier and this is caused by global warming: more ice is melting due to higher temperatures in alpine areas and less iced is added to the glacier from snowfall due to unreliable snowfall in the winter.
There is a lot of evidence to back-up that glaciers are retreating all over the world.
For example, I will use the study of the Rhone Glacier in France to demonstrate this to you. Firstly, the length of the glacier has decreased from 1870 until 2010 by 1300m, showing that it has retreated at a fast rate.
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Secondly, there is a lot of photographic evidence to show how the position of the snout (end) of the glacier has retreated up the river valley. Lastly, there is evidence to show this is due to global warming as the temperature of the the local area has increased by 1.8 degrees Celsius since 1870, which is greater than the average global temperature increase. Furthermore, there is a general agreement among many scientists that this is caused by global warming. On the next column, there is a graph showing the decrease in length of the Rhone glacier, situated in France.
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Yet there are many negative effects to the retreating of these glaciers in alpine and polar regions of the earth. Firstly, the sea level will rise because meltwater from the glaciers will flow into the sea. This will threaten to flood low-level areas across the world.Moreover, many fish species which live in the meltwater ( output) of the glacier will become extinct in the future when all the glacier melts, affecting many alpine ecosystems. Finally, many harmful pollutants which were trapped in the ice will be released when the glacial ice melts and these contribute to global warming.
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