Where are the ice sheets in the present-day climate? In the northern hemisphere, Greenland is covered by an enormous ice sheet which is a few kilometers thick and more than five times larger than the state of California in area.  If this ice sheet were to melt, global sea level would rise by about 7 meters. This is all that remains of the huge ice sheets that covered North America and Eurasia during the last glacial maximum, about 20,000 years ago.