The recent IPCC report discussion of the cryosphere noted medium confidence among experts in the belief that as much as one quarter of the world's mountain glacier mass would disappear if climate projections for 2050 were realized.
Current trends show little change in some mountain glaciers and significant change in others.
The report goes on to describe possible impacts associated with this and other cryosphere-related changes to include changes in seasonal water availability, altered landscapes, and changes in carbon dioxide and methane released to the atmosphere. To improve confidence in the understanding of the dynamic nature of glaciers and the impacts of changes in them, the NASA Pathfinder Program is using existing satellite-based data sets to study global change. Careful reprocessing of existing data from these instruments is paramount to ensure the greatest accuracy possible for comparison of changes in glaciers over time. Landsat images have been used to measure ice flow rates, as well as glacier advance and retreat. SAR data enables monitoring unencumbered by cloud cover and solar illumination conditions.