Retreat of glaciers since 1850

The retreat of glaciers since 1850 is well documented and is one of the effects of climate change. The retreat of mountain glaciers provide evidence for the rise in global temperatures since the late 19th century. Examples include mountain glaciers in western North America, Asia, the Alps in central Europe and tropical and subtropical regions of South America and Africa. Since glacial mass is affected by long-term climatic changes, e.g., precipitation, mean temperature, and cloud cover, glacial mass changes are one of the most sensitive indicators of climate change. Retreat of glaciers is also a major reason for sea level rise. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26-year period from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per yr.

Quotes

 * It is now clear that climatic and environmental disruptions played a major part in the break-up of the Indus civilization. No one can deny anymore that we are now undergoing another major climatic change; a just published study predicts that at least 70 per cent of the volume of Himalayan glaciers in the Everest region may disappear by the end of this century. With human interference (deforestation, excessive damming, etc.) compounding the problem, there have been warnings that Ganga and the Brahmaputra may turn into seasonal rivers even before. This may spell the end of the 3,000-year-old Ganges civilization in its mother-region. We must hope that mitigating steps will be urgently taken to save Ganga from becoming another Sarasvati. The Late Harappans had some time and plenty of space to relocate, fall back on rural lifestyles and adapt themselves to new situations; if Ganga and the Brahmaputra disappear, we may have neither. How will the tens of millions dependent on the Gangetic system survive when Prayag’s triveni sangam consists of three invisible, ‘mythical’ rivers?
 * Michel Danino, "Discovering the Sarasvati River: From 1855 to 2014," in B.R. Mani, (ed.), Indus-Sarasvati (Harappan) Civilization vis-a-vis Rigveda, B.R. Publishing Corporation & Draupadi Trust, New Delhi, 2016, pp. 15-28