Bears on Thin Ice

Over 200,000 years ago, Polar Bears evolved from the Brown Bear (Ursus actos) found in Asia. It is thought that a group of these bears became isolated from the majority of the population by glaciers and ice in Siberia. They adapted to the freezing weather and hunting grounds (seals are their number one source of food). Their light colored fur allows them to camouflage themselves in order to sneak on unsuspecting prey. Polar Bears are designed to live in harsh weather conditions. They can even enter a state of hibernation at any time in the year (unlike other bears who can only do this in the winter).
Polar bears rely on the sea ice as their hunting grounds. 1.5% of this ice is disappearing every decade that passes by. 10% of the pack ice is decreasing each decade as well (this is where the Polar Bear makes his den). Increased ice drift can be very dangerous for these animals, especially for the cubs. Polar bears have to spend more and more time swimming and even though they are avid swimmers, the prolonged time in the water can chill the small cubs and even lead to the drowning of the polar bear. Some Polar Bears off the coast of Alaska have already resulted to Cannibalism.
With the sea ice gone, the Polar Bear's natural habitat will have disappeared along with their way of life. Moving northward is not an option because the polar basin is "deep, cold and unproductive". The sea ice isn't just a hunting ground for Polar Bears. It is a colossal marine ecosystem that supports countless different species of animals from small phytoplankton to Orca Whales.




http://www.arctic.noaa.gov/essay_schliebe.html

http://www.actionbioscience.org/environment/derocher.html

http://www.polarbearsinternational.org/bear-facts/climate-change/

http://www.timesonline.co.uk/tol/news/uk/article767459.ece

Boiling Water

Global climate change not only effects specific animals and habitats, but also large ecosystems. The world’s oceans as a whole are constantly changing due to rising temperatures. There are two factors effecting the ocean: melting land ice (like polar ice caps and glaciers) and “thermal expansion” of the ocean water.

Mount Kilimanjaro ice cap is predicted to melt within twenty years. 82% of this colossal ice cap has disappeared since it was measured in 1912. Ice in the artic that lines the ocean is also melting and thinning. Not only does this lead to ocean expansion, which is harmful to many environments, but it is also threatening to different animals such as the polar bear. Polar bears use the sea ice to hunt for sea lions and other prey. Not only does the sea ice provide hunting grounds for polar bears, it also provides sanction for animals such as the ribbon seal.

As temperatures rise, sea levels follow. This is because increased temperatures cause oceans to become less dense and in turn, they spread out. Sea level today has already risen over 120 meters since then last ice age, which was 18,000 years ago. Studies show that global sea level in the 20^th century rises at a rate of 1 to 2 mm/yr. For many coastlines, this means that there is an average 1.5 meters of land being submerged each year.

Small pacific islands are also being affected. It’s predicted that the small islands known as Tuvalu will be submerged within 50 years. Its water and food production is already being effected today due to the invading saltwater. Global climate change effects a wide variety of ecosystems, but one as large as the ocean is sure to have a devastating chain reaction. There’s no immediate fix to global warming but there are many different ways in which you can reduce your carbon footprint.

Source: http://www.actionbioscience.org/environment/chanton.html