2. GREENHOUSE GASES REGULATE OUR CLIMATE BY
TRAPPING HEAT AND HOLDING IT IN A KIND OF
WARM-AIR BLANKET THAT SURROUNDS THE
PLANET. WITHOUT IT, OUR AVERAGE
TEMPERATURE WOULD BE COLDER BY 54 DEGREES
FAHRENHEIT
WAAAAAAAAAAAAAAY TO COLD TO SUSTAIN OUR
CURRENT ECOSYSTEM!
The Greenhouse Effect is a
GOOD THING!
3. An increase in the concentration of
greenhouse gases leads to an increase in
the magnitude of the greenhouse effect.
(Called enhanced greenhouse effect)
This causes our atmosphere to heat up
faster than it does naturally.
The Enhanced Greenhouse is a
BAD THING!
4. Global warming refers to a rise in the
temperature of the Earth’s
atmosphere.
What is global warming?
5.
6. THE PROBLEM WITH THE
GREENHOUSE EFFECT IS WHEN
HUMAN ACTIVITIES DISTORT AND
ACCELERATE THE NATURAL PROCESS
BY CREATING MORE GREENHOUSE
GASES IN THE ATMOSPHERE
The “Enhanced” Greenhouse
Effect
7.
8. • CARBON DIOXIDE (CO2)
– Source: Fossil fuel burning, deforestation
Anthropogenic increase: 30%
Average atmospheric residence time: 500
years
METHANE (CH4)
– Source: Rice cultivation, cattle & sheep
ranching, decay from landfills, mining
Anthropogenic increase: 145%
Average atmospheric residence time: 7-10
years
Greenhouse Gases
9. NITROUS OXIDE (N2O)
– Source: Industry and agriculture (fertilizers)
Anthropogenic increase: 15%
Average atmospheric residence time: 140-190 years
WATER VAPOR (H2O)
THE MOST IMPORTANT GREENHOUSE GAS!!
SOURCES: EVAPORATION
ANTHROPOGENIC INCREASE: 35 %
Greenhouse Gases
10. BURNING NATURAL GAS, COAL, OIL RAISES THE LEVEL OF CO2 IN
THE ATMOSPHERE
SOME FARMING PRACTICES AND LAND-USE CHANGES INCREASES
THE LEVELS OF METHANE AND NITROUS OXIDE
MANY FACTORIES PRODUCE LONG LASTING INDUSTRIAL GASES
THAT DO NOT OCCUR NATURALLY
AND THOSE GASES ENHANCE THE GREENHOUSE EFFECT
More greenhouse gases means
more heat trapped which increases
the Earth’s temperature
11. DEFORESTATION: TREES USE CO2 AND GIVE OFF O2 IN
WHICH HELPS TO CREATE THE OPTIMAL BALANCE OF
GASES IN THE ATMOSPHERE. AS MORE FORESTS ARE
LOGGED FOR TIMBER OR CUT DOWN TO MAKE WAY FOR
FARMING, THERE ARE FEWER TREES TO PERFORM THIS
CRITICAL FUNCTION. IN ADDITION WHEN THIS WOOD
IS BURNED IT PRODUCES EVEN MORE CO2 IN THE
ATMOSPHERE.
Even more ways these gases are
added to the atmosphere!
12. AS MORE PEOPLE USE FOSSIL FUELS FOR HEAT,
TRANSPORTATION AND INDUSTRY, THE LEVEL OF
GREENHOUSE GASES CONTINUE TO INCREASE. AS
MORE FARMING OCCURS TO FEED MILLIONS OF NEW
PEOPLE, MORE GREENHOUSE GASES ENTER THE
ATMOSPHERE
Population Growth
13. albedo: ability of the
earth's surface to reflect
light
Greenland and Antarctic-
high albedo - light colored
ice sheets reflect sunlight
back into space-if they
melt, more sunlight
would be absorbed by
oceans and warming
would be accelerated.
What is Albedo?
19. Habitat Damage and
Species Extinction
Changes in water supply;
contamination of fresh
water
Effects of Global Warming due to the increase of
greenhouse gases
20. More severe storms;
hurricanes and floods
Droughts, changes in
weather patterns
Effects of Global Warming due to the increase of
greenhouse gases
23. Just the Facts!
A. Scientifically there is no debate: greenhouse gases have risen in recent
years. This is directly related to human activities such as burning fossil
fuels, deforestation and the use of inorganic fertilizers.
B. There has been a significant increase in Carbon Dioxide levels since
1750 and a huge increase since 1950
C. There is more CO2 in the atmosphere than there has been in the last
420,000 years and is rising at a rate of .5% per year
D. The 20th century was the hottest century on record in the past 1,000
years.
E. Since 1860 the average global temperature near Earth’s surface has
risen by .6-.7 C with most of the increase occurring since 1946.
F. The 15 warmest years on record since 1860 have occurred in the last
two decades. The five hottest years on record before 2000 were 1998,
1997, 1995, 1990, and 1999
24.
25. Dealing with the Threat of Global
Warming
3 schools of thought:
1 No Problem is a minority view- global warming is not a
threat but a hoax.
2. Wait and See- Wait until more info is available about
the global climate system. Why spend hundreds of billions of
dollars phasing out fossil fuels and replacing deforestation
with reforestation to help ward off something that might not
happen.
3 Precautionary principle- take action instead of doing
research
4. As a result of uncertainties in climate models scientists
estimate that the projections from current climate models for
the next 50-100 years could be half wrong or twice the
current projections
26. How can we, as a society, slow Global
Warming?
We must reduce current global CO2 emissions by
66-83%
a. quickest and cheapest way is to use energy more
efficiently
b. increased use of nuclear energy
c. using natural gas- help to make the 40-50 year
transition to an age of energy efficiency and
renewable energy
d. phase out gov’t subsidies for fossil fuels over a
decade/gradually phase in carbon taxes on fossil
fuels
27. Continued..
e. shift to renewable energy sources
f. reduce deforestation
g. slow population growth
h. reduce emissions of methane from
leaking pipes and landfills
i. Increase government subsidies for
renewable resources
28. Economics
• 1997- ECONOMISTS & Nobel laureates signed statement:
• a. sound economic analysis shows that greenhouse
emissions can be phased out without harming American
living standards
• b. calling for carbon taxes as part of an international system
of tradable permits for greenhouse gas emissions
• Carbon tax based on
• polluter- pays principle- requires industries &
consumers to pay directly for the full environmental
costs of the fuels they use
• agree to global & national limits on greenhouse gas
emissions
29. Can Techno-Fixes Help?
Techno-fixes- technological solutions for dealing
with possible global warming
Adding iron to oceans-would remove more CO2
through photosynthesis
Unfurling gigantic foil-surfaced sun mirrors in
space to reduce solar input.
Injecting sunlight - reflecting sulfate particulates
into the stratosphere - mimics cooling effects of
giant volcanic eruptions
Massive reforestation, we need to plant trees in an
area the size of Australia
Injecting CO2 into the ground or deep ocean
30. N
S
-waste less _energy__
-develop ____crops_ that
need less water
-move hazardous materials
(storage tanks) away from the
__coast
-prohibit new construction or
remolding on low-lying coastal
areas
-stockpile 1-5 years supply of
key food
-expand existing wild life
reserves with corridors
31. What can YOU do to help
reduce greenhouse gas
emissions?
34. -TURN OFF YOUR COMPUTER OR THE TV WHEN YOU’RE NOT USING IT. UNPLUG
PHONE/COMPUTER CHARGERS
-TAKE SHORTER SHOWERS. HEATING WATER USES ENERGY.
- KEEP ROOMS COOL BY CLOSING THE BLINDS, SHADES, OR CURTAINS, OR OPEN
SHADES TO USE NATURAL LIGHT.
-TURN OFF THE LIGHTS WHEN YOU LEAVE A ROOM.
- USE COMPACT FLUORESCENT BULBS
-COMPOST!
Today YOU can….
