MS Science-Climate Change: Glacial Melting

Scientists have described more than one hundred thousand glaciers in the World Glacier Inventory, but only a small fraction of these have been consistently monitored for long enough to measure climate-related changes in their size or mass. Scientists refer to this collection of about 40 glaciers as "reference" glaciers.

Photos documenting the disintegration of Italy’s Careser Glacier between 1933 (top) and 2012 (bottom). Careser is one of ~40 climate reference glaciers in the World Glacier Monitoring Service's inventory. Photos courtesy of Luca Carturan, University of Padova.

In the 2018 State of the Climate report (edited by NOAA NCEI scientists and published by the American Meteorological Society), scientists reported that in 2017 (the most recent year with complete data), the 42 reference glaciers tracked by the World Glacier Monitoring Service lost an amount of ice equivalent to 921 millimeters (3 feet) of water, while the full network of 142 glaciers lost 951 millimeters (3.1 feet). 
https://www.climate.gov/news-features/understanding-climate/climate-change-glacier-mass-balance

• Worldwide, most glaciers are shrinking or disappearing altogether.
• Between 1980 and 2018, glaciers tracked by the World Glacier  Monitoring Service have lost ice equivalent to 21.7 meters of liquid water—the equivalent of cutting a 24-meter (79-foot) thick slice off the top of each glacier.
• Melting glaciers and ice sheets are the biggest cause of sea level rise in recent decades. 
• Glacier loss is a serious threat to ecological and human water supplies in many parts of the world. 

https://www.climate.gov/news-features/understanding-climate/climate-change-glacier-mass-balance