Posted by admin | 12.27.2012 | Marine Science
Climate change has been identified as a chief environmental villain for years; there are so many philosophies, theories, and conflicting scientific studies involved sometimes it is hard to separate fact from fiction. However, as we watch the polar ice melt and crumble after surviving thousands of years intact it’s clear that something about the planets climate has changed dramatically in the last few centuries.
The melting and refreezing of arctic ice in a natural process that happens with the changing seasons and changing climactic conditions. Unfortunately there has been a lot more melting going on as of recent and not too much of that oh-so-important refreezing.
According to NASA permanent polar ice is melting at a rate of 9% per decade. Now unless you’re an expert meteorologist that statistic can be difficult to visualize. Luckily a study conducted by the United Nations makes that percentage a bit more tangible. According to experts from the World Meteorological Organization between March and September of 2012 the Arctic region lost 11.83 million square kilometers of ice (an area larger than the United States) during record-breaking warm weather patterns. At this rate the Arctic will be iceless by the end of the century.
Average temperatures are rising all over the globe from the ocean to the atmosphere and the resulting effects will not only be felt in the Arctic but worldwide.
The icecaps themselves play a very important part in regulating global temperatures. These huge ice sheets reflects sunlight back out in to space. Albedo (Latin for white) is the term used to measure the refection of solar energy or shortwave radiation from earth back to space. Ice, especially snow covered ice, has a high albedo because it is extremely reflective where as the surface of the ocean does the opposite and absorbs the suns energy. As we lose more and more ice cover, the earth absorbs additional solar radiation and as a result becomes warmer, therefore setting up a potentially life-threatening continuous cycle. Furthermore, shrinking icecaps result in significant changes in the feeding and migration patterns of many animal species including polar bears, walrus, and whales.
The Jet Stream has in the past been a constant regulator of most of the world’s weather. Operating between the arctic and the mid-latitudes this stable energy exchange has become more and more erratic with warming arctic zones. As the jet stream becomes inconsistent severe weather phenomena have increased worldwide. Storms are stronger, longer, and more severe. Droughts, freezes, rainfall, and flooding persist for longer periods as wild temperature swings occur.
Sea level rise is just another side effect of increased global temperatures, but a side effect that will have massive repercussions on humankind.
Sea level is not, in fact, affected by melting floating ice (icebergs and sea ice) as the ices weight displaces a similar amount of water (much like melting ice cubes won’t make your soda overflow your glass). It is a major misconception that as the ice caps melt they add more water to the ocean, thus causing the sea to rise. In actuality, thermal expansion and melting land-ice are the two major contributors to this rise.
Thermal expansion is defined as the tendency of matter to change volume in response to changing temperatures. Plainly put, as the ocean warms it expands. Therefore, melting ice caps contribute to sea level rise by decreasing the amount of solid water (ice) locked in the earth’s surface. The increased percentage of liquid (ocean) begins to warm and thus expand; resulting in sea level rise. At the current rate the oceans are rising at an average of 3.28 feet per decade. According to the Department of Geosciences, a 9 foot increase in sea level will cause major cities like New York and Boston to lose 10% of their land mass and will affect 40.5 million people in the U.S alone.
Land-ice (glaciers and ice sheets) pose another problem, as landlocked ice melts it does actually increase the amount of water in the ocean. If the planet were to lose the ice sheet covering Greenland alone the sea would rise and estimated 19 to 23 feet, devastating coastal cities.
Mankind better start make some changes to global environmental policy soon or else we are going to need to find a really, really big boat.