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Melting of Polar Ice Caps. Changes in the Arctic. Temperatures in the Arctic region are rising twice as fast as they are in other parts of the world. The ice caps in the Arctic are getting thinner because they are melting. Changes in the Arctic.
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Changes in the Arctic • Temperatures in the Arctic region are rising twice as fast as they are in other parts of the world. • The ice caps in the Arctic are getting thinner because they are melting.
Changes in the Arctic • Images from NASA satellites show that the polar ice cap region as a whole is getting smaller at a rate of 9% each decade. • If this trend continues, It is predicted that summers in the Arctic could become ice-free by the end of the century.
Possible Causes for Polar Ice Cap Decline • Geological changes • MilankovitchCycles affect the conditions on the planet over long periods of time and results in ice ages at different times in Earth’s history. • Eccentricity • Obliquity • Precession of the Equinoxes
Possible Causes for Polar Ice Cap Decline • Seasonal changes • Are medium-term changes and they occur every year • Spring • Summer • Autumn (fall) • Winter
Possible Causes for Polar Ice Cap Decline • Global warming (Climate change) • is the gradual increase in the earth's surface temperature • there is much debate on whether this increase in Earth’s temperature is natural or a result of human activities.
Possible Causes for Polar Ice Cap Decline • Average temperatures have climbed 1.4 degrees Fahrenheit (0.8 degree Celsius) around the world since 1880, much of this in recent decades, according to NASA's Goddard Institute for Space Studies.
Possible Causes for Polar Ice Cap Decline • The rate of warming is increasing. • Arctic ice is rapidly disappearing • Glaciers and mountain snows are rapidly melting • Glacier National Park in Montana is an example of glacier melting
Effects of Melting Polar Ice Caps • Contributes to rising sea levels • threatens low-lying areas • erosion • flooding • Will affect weather patterns which has the potential to affect food production around the world. • Example is wheat farming in Kansas. • Kansas would be 4 degrees warmer in the winter without Arctic ice. The arctic ice creates a cold air mass that frequently slides southward into the United States. • Warmer winters would have an affect on winter wheat which needs freezing temperatures to grow. • Warmer summer days would result in a decrease in soil moisture.
Effects of Melting Polar Ice Caps • Loss of habitat and disruption of an ecosystem • the shrinking of the ice caps results in less habitat for the animals, plants, and people that rely on it. Chionodraco hamatus, an Antarctic ice fish, can withstand temperatures that freeze the blood of all other fish types.
Effects of Melting Polar Ice Caps • Warming of the planet • the Polar Ice Cap reflects sunlight (heat) energy back into space, this is called albedo (which is the amount of sunlight reflected by an object) • loss of polar ice means that more of the sun’s energy (heat) is being absorbed by the land and seas
Effects of Melting Polar Ice Caps • Possibility of Rising Sea Levels • “Less ice means more open water. More open water means greater absorption of solar energy. More absorption of solar energy means increased rates of warming in the ocean, which naturally tends to yield faster rates of ice loss.” • Change in salinity of the oceans • the melting of the polar ice caps releases freshwater into the oceans. • Since the northern pack ice is already floating its melting would not independently cause ocean levels to rise. But, with less ice comes less reflectability. • With the warming of the planet due to less polar ice, this could lead to the melting of the ice sheets covering Greenland and southern polar cap, neither of which is floating. • This would result in an increase in sea levels.
Student Activity • Students will select an organism that relies on Polar Ice for survival. • They will write a 2-page report. • Students will use the Grading Rubric for guidance. • Grading Rubric
Sources • http://www.nrdc.org/globalwarming/qthinice.asp • http://www.divediscover.whoi.edu/polar/impact.html • http://www.windows2universe.org/earth/polar/polar_life_intro.html • http://maps.grida.no/go/graphic/climate-change-ice-and-snow-and-the-albedo-effect • http://www.thegeminigeek.com/why-are-the-polar-ice-caps-melting/ • http://www.learner.org/jnorth/images/imageshtml/earth-tilt.gif • http://news.nationalgeographic.com/news/2004/12/1206_041206_global_warming.html • http://www.nasa.gov/centers/goddard/news/topstory/2003/1023esuice.html