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GLACIERS AND CLIMATE CHANGE VIGNETTE
Greg Kientop - Illinois State Geological Survey
January 28, 2012
Thirty people signed up to learn about glaciers and what is contributing to climate change today.
Greg opened his study group presentation with a slide showing an existing glacier in Antarctica. Much of our region of Illinois might have looked like this lifeless landscape as recently as 15,000 years ago. But even though the surface of a glacier appears motionless, actions are taking place beneath the ice. Glaciers are like conveyor belts, dragging rocks and materials in front of them called wasting. Rocks deposited at Wolf Road Prairie when the last glacier receded are still located here.
The next Ice Age is unlikely for at least 1,500 years according to a study conducted at Cambridge University, the University College London, the University of Florida and the University of Bergen in Norway.
Greg shared this information with the group:
There have been five periods of warming in the last million years. Warming occurs through natural processes and most recently with human contribution.
The sun's radiation has increased by .05% per decade since the late 1970's when satellite observations began gathering data. An increase of only .02% in solar output results in warming.
Two shields protect the Earth's biosphere from solar energy.
The first is the Ozone shield which absorbs ultra violet light and prevents it from reaching Earth's surface where it can cause harm to human life and damage the environment. In the 1990's, Ozone depletion was at its worst. Ozone levels are now improving, but Ozone depletion in the southern hemisphere is greater than in the northern hemisphere. Ozone depletion can cause an increase in melanoma cases. The Ozone shield is at its weakest in October.
The second is the Van Allen Belts which intercept charged particles and shoot radiation particles back into space. These belts can interfere with radio signals and communications.
More warming occurs in the northern hemisphere than in the southern hemisphere because of its greater land mass and less water buffering, more populated areas, more pollution and more greenhouse gasses.
Twice as much warming occurs at night than during the day. As night temperatures stay higher, heat is retained in the land longer.
The Urban Heat Island Effect contributes to a warming environment. Since concrete retains more heat than vegetated surfaces, temperatures remain higher as heat is retained in the world's developed cities and regions.
Warm water increases in volume and results in the expansion of ocean levels. Some areas of the oceans rise higher than other ocean areas due to this warming. Warmer seas cause increased wind speeds which are now reaching 80 mph regularly. Jet stream cells are larger and result in more frequent hurricanes affecting coastal developments and shipping. Roads are washed away and structures built near coastlines are lost, causing billions of dollars in damage each year. New Orleans, Florida and now the Carolinas and the northern East Coast are experiencing greater storm events and damage as a result of these changing weather patterns. 80% of the worldwide population lives within 100 miles of a coastline. El Nino is an example of ocean changes impacting weather conditions.
Greg Kientop shows mastodon tusk demonstrating extinct species.
Sea levels rise one to two millimeters a year and tidal fluctuations are effected by lunar cycles. The cold water in floating ice or icebergs does not contribute to raising sea levels as warm water does. Frozen water does not expand as gases in water dissolve when it freezes. These gases are released into the atmosphere, leaving bubbles in the ice.
Snow cover reflects energy and results in temperature cooling. As snow cover melts, more energy is absorbed by the darkened ground and temperatures go up.
In Alaska, roads are built on permafrost. As the climate warms and permafrost thaws, roads sink and must be constantly repaired at great cost.
89% of the world's energy consumption today relies on fossil fuels which produce carbon dioxide when burned. As populations grow, energy needs increase around the world. By the 2030's, the world's fossil fuel supplies will not be able to meet demand. Since world economies are driven by energy, the development of new fuel alternatives is critical.
The blue color of Earth's sky and rainbows are reflected light from the sun's energy. Light energy is complex and changes composition of the atmosphere. CFC's found in aerosol additives, carbon dioxide and methane released into the atmosphere lead to warming, depletion of the Ozone layer and melting glaciers. As carbon dioxide ppm (parts per million) goes up, temperatures rise. There is an approximate 200 year lag time in this process as results manifest. It will take an equal amount of time to reverse and remedy these impacts.
The world's stable temperature of the past 1,000 years is now rising as of the late 20th Century. As a result, about a week has been added to the growing season in our area.
Growing plants absorb and hold carbon dioxide during the summer season acting as carbon sinks. This results in a reduction of carbon dioxide released into the atmosphere. This is reversed during the winter when plants go dormant and more carbon dioxide is released.
Greg concluded his fact-packed program by showing an excavated mastodon mandible and partial tusk. He gave the group the opportunity to hold these ancient bones and experience their enormous weight. He asked us to try to image how strong these animals must have been to be able to plod through the icy tundra with long, curved tusks weighing hundreds of pounds protruding from the fronts of their heads.
So much was learned and we all gained a greater awareness of our world's climate, the natural processes of the planet and the role humans play upon the stage.
Photos by Dave Waycie
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