Transcript The Polar Ice Caps - Ahern236Science

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