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From: Elizabeth Lackey
Date: 10/30/02
Time: 7:41:10 AM
Remote Name: 24.159.72.249
Here are some causal links I came up with.
CAUSAL LINKS:
A>E>B: Intense global warming of more than 0.5 degrees Celsius per decade over the last thirty years has lead to the decline of sea ice. Computer generated models suggest that if greenhouse gases continue to warm the Earth, permanent ice packs will likely melt and will be replaced with seasonal winter ice. Arctic marine animals that depend on sea ice will die out. (“http://archive.greenpeace.org/~climate/arctic99/reports/seaice3.html”)
A>E>B: A lengthening warm season is also contributing to sea ice decline. When there are open areas of water, called “leads“, darker areas of the ocean reflect less sunlight, therefore, warm up and melt even more ice. Many species of marine life are dependent upon sea ice for survival. Arctic animals such as walruses, polar bears, and species of seal would disappear. (“http://archive.greenpeace.org/~climate/arctic99/reports/seaice3.html”)
E>A>B: According to a recent study, higher concentrations of greenhouse gases in the atmosphere will not only warm the lower atmosphere, but will also prevent heat from rising into the upper atmosphere. These lower stratospheric temperatures will increase the depletion of the ozone and delay any recovery. Reduction in the ozone layer means higher rates of ultraviolet radiation, which may have considerable effects on ice-dependent micro-organisms. (“http://archive.greenpeace.org/~climate/arctic99/reports/seaice3.html”)
E>A>H: Sea ice helps modify the transfer of heat, mass, and momentum between the atmosphere and the ocean. It acts a physical barrier to the exchange of gases, such as carbon dioxide, oxygen and water-vapor. Sea ice behaves as an insulating cover between the cold atmosphere and the considerably warmer ocean. During the winter, the loss of heat to the atmosphere over sea ice is “two orders of magnitude smaller” than loss of heat over open ocean. Sea ice also reflects solar radiation back to space rather than allowing the ocean surface to absorb it. This transferring of momentum influences ocean currents. Because sea ice is less salty than sea water, deep vertical convection may be induced. (“http://www.antcrc.utas.edu.au/aspect/seaiceintro.html”)
E>A>H>B: Removal of permanent ice packs would significantly increase precipitation in the Arctic Ocean and North Atlantic. Such precipitation, combined with melted sea ice, would result in the reduction of salinity of the ocean water. The North Atlantic Conveyor, which is the main driving force for the Gulf Stream and global ocean circulation, could be severely reduced by these changes in salinity. Furthermore, northern Europe’s climate would be cooled, global marine life would be disrupted, and the ocean would have a reduced ability to remove greenhouse gases from the atmosphere. (“http://archive.greenpeace.org/~climate/arctic99/reports/seaice3.html”)
RESOURCES:
“http://archive.greenpeace.org/~climate/arctic99/reports/seaice3.html”
“http://encarta.msn.com/encnet/refpages/refarticle.aspx?refid=761559991”
“http://www.antcrc.utas.edu.au/aspect/seaiceintro.html”