The Polar Ice Caps Created by Diane McDonough March 2012 What is happening to the polar ice caps? Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent. Why are the ice caps shrinking? The polar ice caps are undergoing a physical change. MELTING MELTING is a change in state from a solid to a liquid. MELTING occurs when the the water molecules gain enough thermal energy……….. Causing them to vibrate faster which raises their temperature. Eventually the water molecules Break free from their position in the the ice crystals. As a result the ice caps shrink. Walruses, seals, and polar bears are affected by the loss of the ice caps. The overall sea water level rises. The melting of the ice caps is affecting my family. The ice is freezing later in the fall and melting earlier in the spring This shortens our hunting season. Where is all the food? The average bear’s weight has dropped 15% Where will we go for food? We have to swim to larger sea ice to hunt. Which is further off the shore. Many are unable to make the swim, Especially the cubs. Our population is declining! Why is this happening to our home? The melting of the ice caps is caused by GLOBAL WARMING Causes of GLOBAL WARMING CAUSES OF GLOBAL WARMING Include the following chemical reactions • Depletion of the ozone layer • Production of greenhouse gases: carbon dioxide, methane, and nitrous oxide CHEMICAL REACTIONS Occur when one substance breaks down into two or more substances OR Two or more substances combine, forming one or more new substances. The Ozone Layer is a layer in the Earth’s atmosphere that protects the Earth from the sun’s harmful ultra-violet rays. OZONE DEPLETION Occurs because of a Chemical Reactions involving Chlorofluorocarbons The chemical reaction involved……. Then……. Finally…… Chemical reactions also produce greenhouse gases That trap heat in Earth’s atmosphere Sources of greenhouse gas Carbon dioxide is produced through combustion of 1.Fossil fuel 2.Trees and Wood products 3.Solid waste The chemical reaction for burning wood is Methane is produced • During the production and transport of coal, natural gas, and oil • From livestock and other agricultural practices • By the decay of organic waste in landfills Landfill Chemical Reaction: CO2 + 4H2 = CH4 + 2H2O LIVESTOCK Nitrous oxide is produced • During agricultural and industrial activities • Combustion of fossil fuel HOW CAN YOU CHANGE THE WORLD? Stop using or reduce the use of ozone depleting chemicals Chlorofluorocarbons, halons, methyl bromide Carbon dioxide is also removed from the atmosphere (or “sequestered”) when it is absorbed by plants as part of the biological carbon cycle. Plant a tree Ride a bike, walk, or take public transportation Drive a hybrid or more fuel efficient car Use alternative energy sources Use ENERGY STAR appliances and light bulbs Turn off lights and appliances Be part of the solution! Global Warming Theories Presented in this content trailer is one of the theories on Global Warming. The other theory viewed by scientists is that Global Warming is a natural phenomena that has occurred in cycles throughout Earth’s history. NASA Data Reveals 'Average' Ozone Hole in 2007 Music: John Mayer: Waiting for the World to Change David Bowie: Changes Michael Jackson: Man in the Mirror Created by: Diane McDonough Special thanks to Dan Williams References http://www.nrdc.org/globalwarming/qthinice.asp http://ecocentric.blogs.time.com/2010/09/09/climate-change-a-slowdown-onpolar-melt/ http://www.carbonme.org/globalwarming.php http://www.moreinterestingfacts.com/global-warming-facts http://epa.gov/climatechange/emissions/index.html http://www.bom.gov.au/lam/Students_Teachers/ozanim/ozoanim.shtml http://www.theozonehole.com/images/ozoned2.jpg http://earthobservatory.nasa.gov/Features/ChemistrySunlight/chemistry_sunlight3. php http://www.nwf.org/global-warming/effects-on-wildlife-and-habitat/polarbears.aspx