Between the Arctic and the Atlantic Ocean lies the largest island in the world at 810,000 square miles. The terrain is an icy expanse; all of the land is covered by an icecap gradually sloping upward, except for its narrow, mountainous, rocky coast. That ice is over 100,000 years old and extends almost 2 miles underground. It is so massive that its weight presses the bedrock of this island below sea level.
To give you an idea of the magnitude of this degree of ice coverage, only recently was it discovered that this island has a Grand Canyon and geologically, may even be three separate islands. Of course, this is all covered by ice, or at least it was.
If all of the ice on Greenland melted today, it would cause sea level to rise 24 feet. This would erode 440,000 square miles of land along the coastlines of the world and displace about 375 million people. Effectively, wiping out major cities like Shanghai, New York, Charleston, and essentially the whole southern tip of Florida (Miami, Pembroke Pines, St. Petersburg, Coral Springs, etc.).
This large expanse of ice is the island of Greenland, and it has had a record-breaking rate of melting this summer. In July alone, Greenland’s ice sheet lost 197 billion tons of ice. That’s equal to around 80 million Olympic swimming pools. In just one single day, on August 1st of this year, the Greenland ice sheet lost over 11 billion tons of surface ice to the ocean, a record for the volume lost in a single day. That would equate to about 4.4 million Olympic swimming pools.
In fact, recent research suggests that the ice sheet is melting at its fastest rates in centuries, if not thousands of years and the melting seems to be speeding up. Since 2002, Greenland has been losing an average of around 270 billion tons of ice each year. This due in part because as warming increases more precipitation is falling as rain rather than snow, speeding up the melting process.
Greenland is an important component in the global climate system. If a large degree of ice melts not only will sea levels rise but it will exacerbate climate warming. As the sun’s rays enter the earth’s atmosphere, the ice sheet that covers 80% of this island reflects most of the rays back into the atmosphere by what is called the ‘albedo effect’. On the contrary, since water is dark in coloration it absorbs the sun’s rays, subsequently warming the water (and the climate). Light surfaces reflect more heat than dark surfaces.
Another issue with the melting ice comes from what’s been trapped beneath it, frozen organic matter, like animals and plants. The layer of soil that remains frozen throughout the year is known as ‘permafrost’ and can contain organic materials that have been frozen for centuries, unable to decompose. When ice melts and these organisms begin to thaw, they rot and release large amounts of methane, a very potent greenhouse gas.
Climate is a complex system, regulated by a multitude of environmental components. The activity of the ice sheet in Greenland has a large impact on the rest of the world;. to be aware of how Greenland’s ice sheets are changing is to be aware of the future effects of climate change globally and a good place to start in mitigating risks for the future.
Article by Tatiana Eaves.
- Greenland (thumbnail) © Túrelio (via Wikimedia-Commons), 2006
- Greenland ice loss map and graph – National Snow and Ice Data Center (NSIDC)