ice sheets contain enormous quantities of frozen water if the Greenland ice sheet melted. scientists estimate that sea level would rise about 6 meters (20 feet). if the Antarctic ice sheet melted. sea level would rise by about 60 meters (200 feet)
Roughly 20,000 years ago the great ice sheets that buried much of Asia. Europe and North AMERICAN stopped their creeping advance. within a few hundred years sea levels in some places had risen by as much as 10 meters- more than if the ice sheet that still covers Greenland were to melt today. This freshwater flood filled the North Atlantic and also shut down the ocean currents that conveyed warmer water from equatorial regions northward. The equatorial heat warmed the precincts of Antar4ctica in the southern Hemisphere instead, shrinking the fringing sea ice and changing the circumpolar winds. As a result- and for reasons that remain unexplained - the waters of the southern Ocean may have begun to release carbon dioxide, enough to raise concentrations in the atmosphere by more than 100 parts per million over millennial - roughly equivalent to the rise in the last 200 years. That c02 then warmed the globe, melting back the continental ice sheets and ushering in the current climate that enabled humanity to thrive.
