There are around 7 metres of potential sea-level rise locked up in the Greenland icesheets and 57 metres in the Antarctic icesheets.
The mass balance of a glacier or ice sheet is the net balance between the mass gained by snow deposition, and the loss of mass by melting (either at the glacier surface or under the floating ice shelves or ice tongues) and calving (production of icebergs). A negative mass balance means that a glacier is losing mass, and, for grounded glaciers and ice sheets, this mass loss directly contributes to sea level rise (the melting of floating ice shelves and ice tongues does not contribute to sea level rise, because of the lower density of ice as compared to water, which determines the floating portion of the ice). This is one of the reasons why it is important, under a warming climate, to have accurate estimates of the mass balance of glaciers and ice sheets.
The ISMASS group was formed orginally as a SCAR group, then became bipolar when cosponsored by IASC. Now it is also co-sponsored by the Climate and Cryosphere (CliC) project of WCRP.