Various news media articles claim that Two-thirds of glacier ice in the Alps 'will melt by 2100' https://amp.theguardian.com/environment/2019/apr/09/two-thirds-glaciers-alps-alpine-doomed-climate-change-ice
That means 33% melts in 40 years.
So my question is how much did it melt in the last 40 years?
1980 to 2020
According to a report by the US Climate Change Program "virtually all the glaciers in the mid-latitudes are in a state of negative mass balance and are retreating" (2008). By how much each year and specifically in the last 40 years, is presented in the following study as being −5.2 ± 2.2 Gt¹ (metric gigatonnes) per year during the full 1975–2016 interval (2019).
