because that is not real data, its proxy data. and we are legislating and worrying about temperature and co2. the proxy data depends on unvalidated assumptions.
in order to make it real data and understandable to scientists, you would have to do the following:
count how many glaciers there are. record location. try to figure out a testable measure to determine how big a glacier is and validate that measurement, which means do an experiment to prove that you are in fact measuring glacier size. This would be like doing a clinical trial for obesity: you need to validate your measurement device and show it does measure fat or obestity.
then start measurement at every glacier. determine the natural history of that individual glacier and other glaciers in the area, for example the glaciers in glacier national park started melting around 1870. try to integrate the degree of melting or growing bigger and then adjust for sunlight exposure, mining operations nearby, gps coordiantes etc.
this has never been done. recording devices are not even on most glaciers, and no one knows what the natural variability in nature is.
its like saying a stock is going up or down, you need to look at the time lenght. like stock prices, biological measurements "up " or down" depend on the time frame
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