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Global Warming and Climate Change (PowerPoint download)

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					            CHAPTER 18
  Global Warming, Climate Change,
      and the Debate it Causes




 “We are embarked on the most colossal ecological experiment of all time-doubling the
concentration in the atmosphere of an entire planet of one of its most important gases
                 – and we really have no idea of what might happen.”
                                   Paul A. Colinvaux
                  Key Points and
                 Questions to Ask



• What is the Greenhouse Effect and how
  does it relate to global warming?
• Is global warming actually occurring
• Is temperature change – human caused?
• What factors can affect changes in the
  average temperature?
• What are the possible side effects of a
  warmer earth?
• What can we do to slow or adapt to
  global climate change?
 Past Climate Change and the
 Natural Greenhouse Effect
                                                                                         Average temperature over past

• Over the past                                                                                  900,000 years




                  Average surface tem
                                                           17


  900,000 years
                                                         16




                      perature (°C)
                                                         15

  there have                                             14

                                                         13
  been time                                              12


  periods of                                              10
                                                              11



  cooling and                       900
                                                                           9
                                                                                  800    700    600   500   400   300   200   100Present

  warming                                                                                      Thousands of years ago




                                        Average surface temperature (°C)
                                                                                      Average temperature over past 130 years
• For the past                                                             15.0
  10,000 years                                                         14.8

  we have had                                                          14.6
                                                                    14.4
  the good                                                            14.2

  fortune of a                                                             14.0

                                                                           13.8
  stable                                                                   13.6

  climate                                                                      1860     1880   1900 1920 1940 1960
                                                                                                         Year
                                                                                                                        1980 2000 2020
   What is the Greenhouse Effect
For the earth to maintain a
 constant temperature incoming
 solar energy must be balanced by
 an equal amount of outgoing energy
          Greenhouse Effect:
A natural process in which certain
 atmospheric gases warm the lower
 atmosphere by absorbing some of
 the infrared radiation given off
 from the earths surface.

          Actual effect:
   “Tropospheric Heating Effect”
         The Natural Greenhouse Effect




(a) Rays of sunlight         (b) The earth's surface absorbs much of (c) As concentrations of
   penetrate the lower         the incoming solar radiation and         greenhouse
   atmosphere and warm the     degrades it to longer-wavelength         gases rise, their molecules
   earth's surface.            infrared radiation (heat), which rises   absorb and emit more infrared
                               into the lower atmosphere. Some of       radiation, which adds more
                               this heat escapes into space and         heat to the
                               some is absorbed by molecules of         lower atmosphere.
                               greenhouse gases and emitted as
                               infrared radiation, which warms the
                               lower atmosphere.
The Role of the Greenhouse Effect:
• First recognized in 1896 and now
  widely recognized.
• If the GHE acted by itself the
  average surface temperature
  would be 130o F
• Natural cooling takes place by:

 – Releasing heat through evaporation
 – Water vapor molecules rise to the
   clouds and release heat into the upper
   atmosphere


• Actual average temperature: 590F
      Primary Greenhouse Gases:
1. Water Vapor: Controlled by the
   water/hydrologic cycle
2. Carbon Dioxide: Controlled by the
   carbon cycle




Evaluation of ancient glacial ice reveals:
•   Water vapor levels have been relatively
    constant over the past 160,000 years
•   Carbon dioxide levels have fluctuated
•   Fluctuations in global carbon dioxide
    levels correspond with the fluctuation
    of the global temperature
             Carbon Dioxide Levels
            420
                                                 Muana Loa Readings
                                                 CO2 Levels Since 1958




                                     CO2 (ppm)
            370                                  370
                                                 350
CO2 (ppm)




                                                 330
            320                                  310
                                                     40 30 20 10 0

            270

            220
                  Dome Concordia                    Vostok Ice Core
            170 600000         400000     200000                         0
                                  Time (YBP)
  I. Climate Change and Human
             Activities
A. The Argument PRO Global Warming
The Argument for Global Warming, Supported by Scientists,
goverenment, and international organizations

      Carbon dioxide and CFCs are an greenhouse gases and the
      current civilization is pumping more of them into the air

      The fluctuation of the sun is not one of the causes of global
      warming. If it would, it would be insignificant and would follow
      an eleven year cycle

      Computer models have shown that in an ‘business as usual’
      scenario, global warming will increase drastically to almost 3C


      Ever since the industrial revolution, the earth has been
      warming, this shows that the humans are making an difference

      The IPCC reports that global warming does exist and there is a
      consensus by scientists that it exits

      The chief cause of global warming is humans, all other natural
      causes are insignificant.
   1. Largest Contributors to
          CO2 Emissions

1. Thousands of coal burning power
   and industrial plants
2. 700 million gasoline burning motor
   vehicles (555 million of them are
   cars)

Emissions from US factories and
  power plants produce more CO2
  than the combination of 146
  nations (75% of the world
  population)
   2. The role of additional CO2
       in the Atmosphere:
Some climate scientists believe that the
  increased input of CO2 will…

  1. Enhance the earth’s natural
  greenhouse effect
  2.Raise the average global
  temperature of the atmosphere
  near the surface of the earth…
  “Global Warming”
    3. Evidences of a Warmer
           Troposphere
-The 20th century is the hottest in the
  past 1000 years
-Since 1861 the global temperature has
  risen 1.1 – 0.4o F
-10 hottest years on record have occurred
  since 1990
-Melting of land based ice caps and
  floating ice at the poles and Greenland
-Shrinking of glaciers
-Average sea level rise of 4-8” over the
  past 100 years
-Northward migration of some fish, tree
  and other species to find an optimal
  temperature
-Thawing permafrost
Melting
Ice-Caps
The Effect
 of Global
Warming on
 Glaciers

   1911




   2000
                                    Argentina's Upsala Glacier was
                                    once the biggest in South
                                    America, but it is now
                                    disappearing at a rate of 200
                                    meters per year.




The image on the left is from
an 1859 etching of the Rhone
glacier in Valais, Switzerland,
and shows ice filling the valley.
In 2001, the glacier had
shrunk by some 2.5km, and its
'snout' had shifted about 450
meters higher up.
                                     Rising tides
                                     Some scientists predict that a
                                     warmer climate will trigger more
                                     violent storms, which will cause
                                     increased rates of coastal
                                     erosion. This is a section of
                                     shoreline at Cape Hatteras in
                                     North Carolina in the USA,
                                     pictured in 1999 and 2004. The
                                     southern United States and
                                     Caribbean region were battered
                                     by a series of powerful
                                     hurricanes last year.
The Intergovernmental Panel on
Climate Change (IPCC), a
consortium of several thousand
independent scientists, predicts
that sea levels could rise by
between 9 and 88cm in the next
century.
This would threaten low-lying
islands such as Tuvalu in the
Pacific. These images, taken this
year, show the effects of a higher
than usual tide.
                                  As the climate warms up,
                                  mountainous regions may
                                  experience lower levels of
                                  snowfall. This image shows
                                  Mount Hood in Oregon at the
                                  same time in late summer in
                                  1985 and 2002.




More pests

Tree-eating wood beetles are
likely to benefit from a warmer
climate and reproduce in ever-
increasing numbers.
These images show damage to
White Spruce trees in Alaska
caused by the pests.
“DRUNKEN FOREST”
 AND DECREASING
  PERMAFROST
    Food For Thought
• How can these images be
  denied?
• Why would anyone deny these
  images/facts?
• Who would benefit from the
  denial?



• Why would they be falsified?
     B. The Argument AGAINST Global
                Warming
The Argument against Global Warming, Supported by Scientists as they
believe that global warming does not exist


        Water is the main greenhouse gas, carbon dioxide accounts to
        one to five percent of the greenhouse effect

        About half of the people who prepared the IPCC report does not
        agree with it, which is not an consensus. Also it does not take
        in account that water is the major greenhouse gas.

        Computer models are unreliable, 17 different models were given
        the same information and they came up with 17 different
        answers



        The sun’s magnetism is also helping global warming

        There was a little Ice Age just before 1900 and we are just
        simply coming out of it.

        Most of the drastic predictions by global warming leaders are
        simply ploys to get money.
    1. Other possible Factors
     Affecting Global Temps.
A. Solar Output


B. Earths                                Clouds 50–55%

   Reflectivity
                  City 10–15%
                                                    Snow 80–90%

  -Albedo;
  ability to                    Grass 15–25%             Forest 5%

  deflect light                            Bare sand 30–60%

                    Oceans 5%
C. Oceans

• Removes 29% of the CO2, but water
  is less capable of dissolving gas as
  the temperature increases
• As the temperature increases CO2
  will bubble out of the oceans.
• Oceans store heat energy deep in
  the water and may release it into
  the atmosphere
• There is a conveyor belt that
  transfers heat around the world
  that runs based on differences in
  water density. Fresh water from
  melted ice may throw the system
  off
Main Ocean Currents




              Adapted from IPCC SYR Figure 4-2
D. Air Pollution
    -Soot is the second biggest
   contributor to global warming
    -Produced as a product of
   burning of coal and diesel fuel

    -Aerosols (tiny droplets and
   solid particles) actually help
   reduce global warming
    -Serve as condensation nuclei
   that lead to increased cloud cover
   and increased reflection of light
E. Mini Ice Age
F. EARTHS ECCENTRICITY, OBLIQUITY,
PRECESSION
Based on the Milankovitch theory - an
explanation of long term climate change
based on mathematical equations.
II. Effects of a Warmer World
 - Changes in water
 distribution patterns
                             Present

                             Future
 - Changes in plant/animal
                             Overlap
 distribution

 -Ocean currents and sea
 level
 Projected image
of Florida with a
18- 20 foot rise in
     sea level.
  -Possible extreme
  change in weather
  patterns.




-Possible Health Risks
            Agriculture                 Water Resources                                   Forests

•   Shifts in food-growing areas      • Changes in water supply           •     Changes in forest composition and
•   Changes in crop yields
                                      • Decreased water quality                 locations
•   Increased irrigation demands
                                      • Increased drought                 •     Disappearance of some forests
•   Increased pests, crop diseases,
    and weeds in warmer areas         • Increased flooding                •     Increased fires from drying
                                                                          •     Loss of wildlife habitat and species


            Biodiversity
                                                                                    Sea Level and Coastal Areas

•   Extinction of some plant and                                      •       Rising sea levels
    animal species
                                                                      •       Flooding of low-lying islands and
•   Loss of habitats                                                          coastal cities
                                                                      •       Flooding of coastal estuaries,
•   Disruption of aquatic life                                                wetlands, and coral reefs
                                                                      •       Beach erosion
                                                                      •       Disruption of coastal fisheries
                                                                      •       Contamination of coastal aquifiers
                                                                              with salt water

        Weather Extremes                                                                Human Health
                                                 Human Population
•   Prolonged heat waves and                                              •    Increased deaths from heat and
    droughts                                                                   disease
                                      • Increased deaths
                                                                          •    Disruption of food and water supplies
•   Increased flooding                • More environmental refugees       •    Spread of tropical diseases to
•   More intense hurricanes,          • Increased migration
                                                                               temperate areas
    typhoons, tornadoes, and                                              •    Increased respiratory disease
    violent storms
                                                                          •    Increased water pollution from coastal
                                                                               flooding
III. Dealing With Climate Change
•FOUR schools of thought:
   - Do Nothing


   - Do more research


   - Act now to reduce risks of
     climate change.


   - Act now as part of no-
     regrets strategy.
 A. Ways to Reduce the Climate
        Change Threat

1. Improve energy efficiency
2. Increase practices that emit
    less GH gases
3. Switch form coal to more
    renewable energy alternatives.
4. Promote various forms of
    legislation toward the goal of
    decreasing GH gases
(carbon credits, Kyoto Treaty)
5. Find ways to sequester CO2 gas
  What is Being Done to Reduce
  Greenhouse Gases? (469-471)

Kyoto Treaty:
• Kyoto Japan 1997: Meeting to
  negotiate a treaty to slow
  global warming
Requirements:
1. 38 developed nations to 5.2%
   below 1990 levels by 2012
2. Developing nations did not
   have to participate at first
3. Allowed emissions trading
   Should the USA ratify the Kyoto Protocol?
Point 1:                   Counter Point 2:
• Failure to require 81%   • Could be met with no
  of world population        net cost by
  (Developing nations         – Tax breaks for efficiency
  including China) to           and renewable energy
  participate                 – Cutting tax breaks and
Counter Point 1:                subsidies for the fossil
                                fuels
• 19% of the world         • Point 3:
  population makes
  63% of greenhouse        • Does little to slow global
  gas                        warming
Point 2:                   Counter Point 3:
• Devastating impact       • It is not a 50-100 yr
  on US economy &            treaty, rather a starting
  workers                    point
B. What
 can we
   do?

				
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posted:4/7/2012
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