Transcript Arctic Ice - Helena High School

• Notes: The Global
Warming Issue
• If you were gone, get a copy of the
handout and then view the presentation.
Take notes on the handout as you do this.
Notes on Handout: Global Warming
Compared to Ozone Issue
Global Warming is often referred to as . . .
• 1. Is the world getting warmer?
• Overwhelming majority of scientists think it is.
• Evidence?
• Increasing: temperatures, humidity, sea level
• Decreasing: sea ice, glaciers, snow cover
Arctic Ice
Arctic Ice Cover Summer 1973
Arctic Ice Is Melting
Arctic Ice Cover Summer 2003
• 2. Why is the world getting warmer?
•
•
•
•
Skeptics:
think it is a natural climate change.
Proponents:
think it is caused by human activity.
(Greenhouse Theory)
A. Greenhouse Theory
(controversial)
Burning
of fossil
fuels
More CO2
into air
(10-min of DVD)
Increases
Earth’s
greenhouse
Effect (cat in car)
CO2
World
gets
warmer
• Mercury: over 700 F to less than -300 F
• Venus: average temp. is 900 F
• Why is Venus hotter than Mercury?
• Earth: average temp. is 59 F
• Mars: average temp. is -67
B. Greenhouse Gases:
•
•
•
•
Water vapor and clouds
#1 Greenhouse gas
Methane
Swamps, permafrost, termites, cows, coal
mines, landfills, rice fields
• Carbon dioxide (CO2)
• Burning of fossil fuels
• Cement production
• Deforestation
1975
1989
2001
C. Fossil Fuels
• Coal
• Burned to generate electricity
• Natural Gas
• Burned to heat homes and water
• Oil (petroleum)
• Fuel for trains, planes, autos., etc.
CO2 levels were in balance for hundreds of years
prior to our Industrial Revolution
Year
With the burning of fossil fuels, CO2
emissions grew larger than removal.
American
Chinese
(Biomass)
Near Colstrip
3. What will be the consequences of
climate change (controversial)
• Rising sea level
• Ocean acidification
3. What will be the consequences of
climate change (controversial)
•
•
•
•
•
•
•
Rising sea level
Ocean acidification
Desertification
More frequent and more severe storms
Changes in water resources
Extinctions
More disease and infestations
4. What should we do about it?
It’s very complicated!
• A. Cap carbon? Carbon tax?
• Limit the amount of CO2 a nation or business can
emit
• The problem with this?
• Economic impact
B. Carbon Capture and Sequestration
• Collecting CO2 emissions and storing them
underground
C. Reduce your carbon footprint
• estimate of how much carbon your
activities/lifestyle puts into the air