Melting Ice in Greenland
greenland, the world’s largest island, has a population of about 60,000 people. Glaciers as deep as 3.2 k ilometers (2 miles) cover about 80% of this mountainous island, which is roughly onefourth the size of the continental United States. Greenland’s ice is a result of the last ice age and survives only because of its huge mass. Its glaciers contain about 10% of the world’s freshwater—enough water to raise the global sea level by as much as 7 meters (23 feet) if the glaciers all melt. This would flood many coastal cities and much of the earth’s farmland. The large moving ice mass in a glacier scrapes along very slowly, but it can pick up speed when meltwater flowing downward through its crevices lubricates its bottom, which sits on bedrock. As the thickness of the glacier decreases, its grip on the land weakens, further accelerating its movement toward the sea. Recent satellite measurements show that Greenland’s net loss of ice more than doubled between 1996 and 2007 and is not being replaced by increased snowfall (Figure 19-C). According to glacial ice expert Konrad Steffen, the record amount of ice melted from Greenland’s ice sheet during
Figure 19-C Areas of glacial ice melting in Greenland during summer increased dramatically between 1982 and 2007. If this net melting of Greenland’s land-based ice continues over a number of decades, the world’s average sea level will rise sharply. (Data from Konrad Steffen and Russell Huff, University of Colorado, Boulder)
the summer of 2007 was equivalent to two times all of the ice in the Alps of south-central Europe. If this trend continues throughout much of this century, more of Greenland’s land-based ice will melt, helping to raise the world’s average sea level
Critical Thinking List three ways in which the rapid melting of ice in Greenland over the next few decades could affect your lifestyle or that of any children or grandchildren you might have.