Glacier changes

Glaciers are naturally subject to changes in line with the Earth's climate variability. Area and length changes of glaciers which are not influenced by debris cover, calving, or dynamic instabilities show a filtered and delayed climate signal while the glacier mass balance can be more directly linked to climate. Glaciers retreated on average strongly since the end of the Last Glacial Maximum about 19 000 years ago with several periods with glacier advances especially during the Holocene. Clearly visible moraines of the Little Ice Age indicate the maximum glacier extent occurring between the seventeenth to the late nineteenth century. The glaciers retreated again strongly and lost mass since then with an accelerated rate since the 1980s. However, glacier changes are not homogeneous throughout the globe but local deviations and even regions with stable glacier conditions exist. Further significant reduction of glacier mass is projected for the twenty-first century