The EarthΓÇÖs polar ice sheets, which cover most of Greenland and Antarctica, contain about 77 percent of the world's fresh water. If these ice sheets were to melt, sea levels would rise worldwide and flood hundreds of coastal cities. Even small changes in global ice sheets can have serious effects on global sea levels and, therefore, coastal regions.
Temperature records in the Antarctic Peninsula indicate a warming trend over the past few decades. Some scientists are concerned that the West Antarctic ice sheet, most of which lies between the Antarctic Peninsula and the Transantarctic Mountains, may suddenly increase its discharge of ice into the oceans as a result of the warming. Such an increase could cause rapid increases in sea levels.
