Global Climate Change PowerPoint

					                        Global Climate Change
                         Fiction, Facts, Uncertainties,
                            Challenges & Impacts


                              David D. Houghton
                          Atmospheric & Oceanic Sciences
                                 UW – Madison
                           Email: ddhought@facstaff.wisc.edu




                            UW-Superior     April 9, 2003




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                                        Lecture Outline

                  1.    Introduction

                  2.    What the unconvinced people are saying

                  3.    Facts

                  4.    Uncertainties

                  5.    Challenges

                  6.    Human impacts on climate change

                  7.    Climate change impacts on humans & the environment

                  8.    What can we do about it?

                  9.    Concluding remarks


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                        What the unconvinced people are saying…


                   1.    ―Theory remains entirely unproved.‖

                   2.    ―One-in-three chance … that experts are wrong.‖

                   3.    ―Models are incapable of handling … water vapor.‖

                   4.    ―Troposphere should be warming faster than the
                         surface.‖

                   5.    ―If the weather folk can’t figure out what’s happening
                         for the rest of the week, how can they tell us what the
                         climate will be for the next 50 years?‖

                   6.    ―Guess what? Antarctica’s getting colder, not warmer.‖

                   7.    ―Global warming is still just a theory.‖



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                                            Facts…


                   1.   Global mean temperature has been going up in the last
                        140 years.
                   2.   The magnitude of this variability does not exceed natural
                        variability.
                   3.   Concentration of carbon dioxide has been going up as
                        well as other greenhouse gases.
                   4.   Radiative theory of atmospheric gases (greenhouse) and
                        aerosols is important.
                   5.   Climate change involves the entire ―earth system‖ not
                        just the atmosphere.
                   6.   Future projections face uncertainties in emission
                        production, modeling, and impacts.
                   7.   Several thousand scientists from 40+ countries all over
                        the world have been involved.




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                                   Global Mean Temperature
                                                   (140 year record)




   Combined annual land-surface air and sea surface temperature anomalies (C°) 1861 to 2000 relative to
   1961 and 1990. Two standard error uncertainties are shown as bars on the annual number.



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                        Regional and Seasonal Temperature Trends




                                                            Temperature trends
                                                              over 1977-2001

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                                                1,000 Year Temperature and Instrumental Data
                                    1.0
 Northern Hemisphere anomaly (°C)
   Relative to 1961 to 1990 mean




                                    0.5




                                    0.0




                                    -0.5




                                    -1 .0
                                         1000         1200      1400          1600   1800      2000

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                                                                       Year                           7
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                                 Overview of Past Climate Temperatures




                                       2 x CO2
  Temperature (K)




                          Decades                                       Millions of Years
                    Schematic comparison of possible future greenhouse warming with estimates of past changes
                    in temperature. Pleistocene glacial-interglacial cycles are more numerous than shown. The
                    characteristic amplitude of global temperature change during glacial-interglacial cycles in 3-4 K.
                    Note that pre-Pleistocene changes are not well fixed in magnitude, but their relative warmth is
                    approximately correct. Maximum warming in the Cretaceous is based on estimates by Barron
                    and colleagues.

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                Carbon Dioxide
                                    Indicators of the Human
                                 Influence on the Atmosphere
                                   During the Industrial Era

                                 (a) Global atmospheric
                                 concentrations of three well
                Methane          mixed greenhouse gases




                                           (b) Sulphate aerosols
                                           deposited in Greenland ice

                Nitrous oxide
                                             Sulphur




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                   Visible Radiation                                    Infrared Radiation




        The Earth’s annual and global mean energy balance. Of the incoming solar radiation, 49% is absorbed
        by the surface. The heat is returned to the atmosphere as sensible heat, as evapotranspiration (latent
        heat) and as thermal infrared radiation. Most of this radiation is absorbed by the atmosphere, which in
        turn emits radiation both up and down. The radiation lost to space comes from cloud tops and
        atmospheric regions much colder than the surface. This causes a greenhouse effect.
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                                  Global Climate System




                        Schematic view of the components of the global climate system (bold), their processes
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                        Carbon Cycle in Earth System Components




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                                            Uncertainties…


                   1.   Human induced forcing changes to present
                   2.   Future emissions scenarios
                        [Special Report on Emission Scenarios (SRES) study]
                        A1FI: fossil fuel intensive energy system
                        A1T: non-fossil fuel intensive energy system
                        A1B: no one energy source relied on
                        A2: self-reliant economy, preservation of local identities
                        B1: service and information economy, clean
                                 technology, global solutions
                        B2: B1 with local solutions, increasing population, less
                                 technology
                   3.   Model predictions – global mean
                   4.   Model predictions – local conditions
                   5.   Impacts




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                                                   The Global Mean Radiative Forcing of the Climate System
                                                              For the year 2000, relative to 1750
  Radiative Forcing (Watts per square metre)

                                               Warming
                                               Cooling




                                                                 Level of Scientific Understanding
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                           Forcing Variations from 1770 to 2100

         Forcing (Wm –2)




                                             Year

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Global temperature change (°C)
                                                                                                    Variations Among Models
                                                                                                    for one Emission Scenario


                                                                                                           Precipitation




                                                                  Global precipitation change (%)
                                 Years from start of experiment

                                       Temperature




                                                                                                      Years from start of experiment




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                               Overall Predictions for Future Temperature Change
                                                  (global mean)
     Temperature change (°C)




                                                    Year

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                  Regional Control-Observed, Control-Double CO2
                         Winter, Temperature     Winter, Temperature

                                 CO2 – Control        Control – Observed




                          *                       *
                         Summer, Temperature     Summer, Temperature
                                 CO2 – Control        Control – Observed

                                                                                 – Central North America
                                                                           * CNA – South East Asia
                                                                             SEA
                                                                            SAH – Sahel
                                                                            SEU – Southern Europe
                                                                            AUS – Australia
                                                                            NEU – Northern Europe
                                                                            EAS – East Asia




                         *                        *
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                        Crop yields in SE Asia

                                      -61 to +67
                                  *   -50 to +30   *




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                                              Challenges

                        A. Nature of climate system
                           1. Analysis must consider entire climate system and all of
                              humanity
                           2. Extensive natural climate variability
                           3. Global connections for both climate forcing and climatic
                              response
                           4. Uncertainties in outcomes involve uncertainties in many
                              components
                           5. A small change in global means can translate to large
                              changes in local means/extremes

                        B. Needs for research
                           1. Improve data – longer data, error analysis, more global
                              coverage
                           2. Improve theory – radiation-aerosol, cloud drops-aerosol
                           3. Improve models – parameterization for small scale
                              components
                           4. Separating naturally-induced fluctuations from human
                              effects

                        C. Nature of people
                           1. Implement controls on human impacts on the environment
                           2. World cooperation
                           3. Look at ourselves
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                                       Separating Human from Natural
                                            Temperature Trends
                          0.1000                                      OBSERVED

                                                                      95th Percentile: GFDL

                                                                      95th Percentile: ECHAM

                                                                      95th Percentile: UKMO
                          0.0100
 Linear Trend (°C yr-1)




                          0.0010




                          0.0001
                                   0     20       40          60             80                100
                                               Trend Length (years)
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     Vertical
    Variations




                                      Pressure (hPa)
    Footprint              Model
                        Changed CO2

   Zonal-Mean
 Annual-Average
 Temperature (°C)




                                      Pressure (hPa)
                           Model
                        Changed CO2
                         & Sulphur


                                      Pressure (hPa)




                        Observed
                        Changes




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                        Uncertainties in Detection & Attribution of
                                         Climate Change
                                (Sept. 2002 paper – Bull. Amer. Meteorological Society)
                                     Assessment by 19 experts (11 from the U.S.)

                   Evidence type:
                   1.   Century-long trend in global mean surface temperature
                   2.   30-year trend in vertical pattern of temperature
                   3.   30-year trend in geographical pattern of surface temp.
                   4.   30-year trend in diurnal temperature range over land

                   Mean assessment of probability of detection:
                   1.   95%
                   2.   99%
                   3.   80%
                   4.   73%

                   Mean expected fraction attributed to greenhouse forcing
                   1.   72%
                   2.   20%
                   3.   61%
                   4.   45%

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                             Human Impacts on Climate Change


                    1. Types of impacts

                    2. Focus on greenhouse gases – primarily CO2

                    3. Driving forces for the future

                    4. Basic scenarios

                    5. Scenario outcomes

                    6. National and personal lifestyles (U.S.)




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                                  Types of Human Impacts


                   1.   Increase in greenhouse gases

                   2.   Increase in aerosols

                   3.   Change in surface conditions
                        (e.g. albedo, wind, evaporation)

                   4.   Change in clouds
                        (e.g. contrails, pollutants, etc.)




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                                                                     Correspondence of O2 with CO2 Changes



                  O2 concentration, difference from standard (ppm)




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                                                                             CO2 concentration (ppm)         26
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                        Disposition of CO2 Added by Humans




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                           Driving Forces for Future Human Impacts


                    1.   Population

                    2.   Economy (income per capita and regional differences)

                    3.   Technology
                         a. Energy production – fossil fuels and non-fossil fuels
                         b. Energy use efficiency
                         c. Land use

                    4.   Energy structure: Coal – Oil/Gas – Renewables / Nuclear

                    5.   Land use: Forests – Croplands & Energy Biomass – Other
                                                                        (grasslands, etc.)

                    6.   Agriculture



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                        SRES Scenarios for Emissions




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                                          Basic A Scenarios

                        A1. Storyline and scenario family describes a future world of
                            very rapid economic growth, low population growth, and
                            the rapid introduction of new and more efficient
                            technologies. Major underlying themes are convergence
                            among regions, capacity building, and increased cultural
                            and social interactions, with a substantial reduction in
                            regional differences in per capita income. Technology
                            subsets are:
                                     A1FI: fossil fuel intensive energy system
                                     A1T: non-fossil fuel intensive energy system
                                     A1B: no one energy source relied on

                        A2: Characterized by self reliant economy, preservation of
                            local identities. Storyline and scenario family describes a
                            very heterogeneous world. The underlying theme is self-
                            reliance and preservation of local identities. Fertility
                            patterns across regions converge very slowly, which
                            results in high population growth. Economic
                            development is primarily regionally oriented and per
                            capita economic growth and technological change are
                            more fragmented and slower than in other story lines.
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                                         Basic B Scenarios

                        B1. Characterized by a service and information economy,
                            clean technology, and global solutions. The storyline and
                            scenario family describe a convergent world with the
                            same low population growth as in the A1 storyline, but
                            with rapid changes in economic structures towards a
                            service and information economy, with reductions in
                            material intensity, and the introduction of clean and
                            resource-efficient technologies. Emphasis is on global
                            solutions to economic, social and environmental
                            sustainability, including improved equity, but without
                            additional climate initiatives.

                        B2: Characterized B1 with local solutions, increasing
                            population, and less technology. The storyline and
                            scenario family describe a world in which the emphasis is
                            on local solution to economic, social, and environmental
                            sustainability. It is a world with moderate population
                            growth, intermediate levels of economic development,
                            and less rapid and more diverse technological change
                            than in the B1 and A1 storylines. While the scenario is
                            also oriented towards environmental protection and
Global Climate Change                                                                   31
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                               Population Projections


                                                        Population
                                                        Projections
                                                        Historical data from
                                                        1900 to 1990 (based
                                                        on Durand, 1967;
                                                        Demeny, 1990; UN,
           Global Population




                                                        1998, for medium) and
                                                        IPCC IS92 scenarios
               (billion)




                                                        (Leggett et al., 1992;
                                                        Pepper et al., 1992)
                                                        from 1990 to 2100.




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                        Economic Zones


                                         OECD90 – Developed
                                         Countries



                                         REF – Economic Reforming
                                         Countries


                                         ASIA –Developing
                                         Countries of Asia



                                         ALM – Developing
                                         Countries Elsewhere




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                                                                Economy GNP
                        Income per Capita by World and Regions (103 1990 US$ per capita)

                    Income per capita in the world and by SRES region. Numbers in brackets give minimum and
                    maximum values of the SRES scenarios. The range for 1990 illustrates differences in base-
                    year calibration across models.


                                                              2050                                                      2100

Region                  1990              A1          A2              B1            B2            A1             A2            B1            B2
OECD90            17.8-20.6              50.1         34.6           49.8          39.2        109.2            58.5         79.7           61.0
                                  (39.4-62.3)   (32.3-54.0)    (40.3-52.0)   (35.1-42.2) (69.8-115.7)    (48.0-78.7)   (70.6-84.7)   (50.1-73.2)

REF
IND


ASIA
ALM

DEV                     0.7-1.1         15.9            3.9          10.9            8.1         66.5           11.0          40.2         18.0
                                  (11.4-16.7)     (3.3-5.1)     (7.5-14.8)     (3.9-8.4)   (41.4-69.8)   (10.3-13.7)    (40.2-45.2) (14.2-21.5)
WORLD



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                               CH4 emissions (TgCH4)   CO2 emissions (GtC)




                        Year
                               SO2 emissions (TgS)      N2O emissions (TgN)
                                                                              Greenhouse Gas Emissions




                        Year




            35
                                     Global Energy Structure

 Global primary energy structure,
 shares (%) of oil and gas, coal, and
                                                    Oil / Gas
 non-fossil energy sources – historical
 development from 1850 to 1990 and in
 SRES scenarios. Each corner of the
 triangle corresponds to a hypothetical
 situation in which all primary energy is
 supplied by a single source – oil and
 gas on the top, coal to the left, and
 non-fossil sources to the right.
 Constant market shares of these
 energies are denoted by their
 respective isoshare lines.




                   Coal



                                                                Renewables/Nuclear

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                                      Global Energy Resources
                 Global fossil and fissile energy reserves, resources, and occurrences (in ZJ ( 10 21J)).
                 Global and regional estimates are discussed in detail in Rogner (1997) and Gregory and
                 Rogner (1998).




                 Global renewable energy potentials for 2020 to 2025, maximum technical potentials, and
                 annual flows (in EJ (1018 J)).




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                 Estimated Net Energy Use
                      in USA in 1972




                                      *
                               *
                                       *




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Transportation
                                           Passenger                 Freight
Energy Efficiency
USA Study 1974




                               Urban          Intercity




                        Transportation energy efficiency. All efficiencies shown are expressed in
                         terms of gasoline equivalent (125,000 Btu/gal = 34,839,536.62 kJ m –3 ).

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          Climate Change Impacts on Humans & the Environment

                        A.   Terrestrial ecosystems
                              •      Agriculture
                              •      Forests
                              •      Desert and desertification
                              •      Hydrology and water resources
                        B. Ocean systems
                             1.    Sea level
                             2.    Coastal zones and marine ecosystems
                        C.   Human ―systems‖
                              1.     Settlements, energy and industry
                              2.     Economic, insurance, and other financial services
                              3.     Human health
                                      a. Vector borne diseases
                                      b. Water-borne and food-borne diseases
                                      c. Food supply
                                      d. Air pollution
                                      e. Ozone and ultraviolet radiation
                        D. Atmospheric systems
                             1.    Weather
                             2.    Storms
                             3.    Floods and droughts
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                             4.    Extremes                                              40
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                        Agriculture in Latin America
                                                        Yield Impact (%)

                                                           decrease
                                                           increase
                                                           increase
                                                           decrease

                                                              -30
                                                           -40 to –30

                                                           -50 to –15
                                                            -25 to –2
                                                           -10 to +40

                                                              -20
                                                              -24
                                                              -61

                                                           -61 to –6

                                                           -36 to –17

                                                           -5 to –10



                                                       increase-decrease


                                                            -16 to +2
                                                             -8 to +7
                                                            -8 to +13
                                                           -22 to +21

                                                             -10b
                                                           -8 to +5c
                                                             -15d
                                                          -13 to +10c
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                        Water Availability Resources
                        Water availability in 2050 for the present climatic conditions
                                and for three transient climate scenarios.
                                              (m3 / year / person)




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                        Sea Level Rise Impacts




                                                 1.0
                                                 0.1

                                                 17.5
                                                  8.4
                                                  0.2
                                                   -
                                                  1.0
                                                  1.1
                                                  0.4
                                                  0.6
                                                 12.5
                                                  2.1
                                                  80
                                                  0.3
                                                  5.9
                                                  2.0
                                                  0.5
                                                  3.1
                                                  1.4
                                                  2.9
                                                  0.3
                                                  0.1
                                                  0.6


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                        Vector-Borne Disease Susceptibility
                                                          Likelihood
                                                      *    of Altered
                                                                       *
                                                       Distribution with
                                                       Climate Change




                                                                    Major tropical vector-
                                                                    borne diseases and the
                                                                    likelihood of change of
                                                                    their distribution with
                                                                    climate change.




                                                                       + = likely
                                                                       ++ = very likely
                                                                       +++ = highly likely
                                                                       ? = unknown


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                                     Temperature Indicators




                        Schematic of observed variations of various temperature indicators.

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                               Hydrological and Storm Indicators




                    Schematic of observed variations of various hydrological and storm-related indicators.

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                             Atlantic Tropical Storm Variability


                                                             Annual Number of Atlantic Hurricanes (solid bar)
                                                             And Tropical Storms (open bar)




  Time series of the annual number of Atlantic tropical cyclones reaching at least tropical storm strength (open bar)
  and those reaching hurricane strength (solid bar) for 1886-1988. The average numbers of tropical storms and
  hurricanes per year are 8.4 and 4.9, respectively.




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                   Human Responses to Climate Change

                        1.   Why should we care?

                        2.   Modify our own life style

                        3.   Mitigation and adaptation

                        4.   Modify national and global practice

                        5.   Influencing public policy




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                                      Why Should We Care?
          •   We don’t know exactly what will happen with global warming or what the impacts will
              be. And where or when they will hit hardest.

          •   But scientists have a pretty good general idea of what’s to come. They tell us the
              possible impacts could be far-reaching and could cause serious problems:

          •   Sea level will continue to rise, eroding beaches and increasing the damage from storms
              and leading to loss of wetland habitats. Some island nations will disappear.

          •    Increasing temperatures are likely to affect human health:

                    •   Warmer temperatures mean mosquitoes will spread in areas that were previously too cold for
                        them to survive. Mosquitoes carry infectious diseases like malaria and encephalitis.

                    •   Ground-level ozone pollution will likely worsen, increasing respiratory diseases like asthma.

                    •   Deaths from heat waves will rise.

                    •   Some plants and animals may face extinction if habitat changes.

          •   Changing weather patterns could affect agriculture. Northern states could actually
              experience longer growing seasons. The U.S. Great Plains could have frequent
              droughts.

          •   Some forests may disappear, leading to extinction of wildlife species—changes in
              biodiversity.

          •   Economic effects: Billions of dollars in property damage from sea level rise and
              worsening storms.                                                                                         49
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                           What Can We Do About Global Warming?
               There are simple steps each of us can take that will help reduce our emissions of greenhouse gases.
                                                      Just a few examples:

               •        Recycling saves the energy required to manufacture new products.

               •        Give your family car a day off by riding your bike, taking the bus, or walking.

               •        Plant trees – they absorb carbon dioxide.

               •    Read and learn about global warming.

               •        Save electricity by turning off the TV and lights when you’re through with them.

               •    Go solar – a solar system to provide hot water can reduce your family’s carbon
                    emissions by about 720 pounds a year.

               •        Encourage others to take these simple actions.

               •    Preserve forests – they act as carbon dioxide ―sinks‖ – in other words, they absorb
                    carbon dioxide.

               •    Develop renewable energy technologies to reduce dependence on fossil fuels.

               •    Use energy more efficiently. For example, the federal government has a variety of
                    voluntary partnership programs with industry to reduce greenhouse gas emissions by
                    using energy more efficiently.


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                    Mitigation and Adaptation Diagram from SRES
                                               CLIMATE CHANGE
          Human Interface                          Including Variability




                                                        Exposure



                                                      Initial Impacts




                                                                           Vulnerabilities
                                                         or Effects
             MITIGATION

                                         Impacts
       Of Climate Change via
      GHG Sources and Sinks                           Autonomous
                                                      Adaptations


                                                       Residual or                                      Planned
                                                       Net Impacts                                    ADAPTATION
                                                                                             to the Impacts and Vulnerabilities




                                                   Policy Responses


                               Places of adaptation in the climate change issue.

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                          Recent Reductions in
                          China’s Greenhouse
                          Gas Emissions



                        Focusing only on CO2 emissions form
                        fossil fuel combustion, against which
                        we can compare other countries, we
                        calculate that China’s emissions
                        dropped from 2950 Tg (teragrams of
                        CO2, 1 Tg = 1 million tonnes) in 1996
                        to 2690 Tg in 2000, a reduction of
                        8.8%. This decrease, which China
                        achieved while most other countries
                        were increasing their emissions,
                        represents about 1% of the global
                        CO2 emissions from fossil fuel
                        combustion in 2000 of 25,300 Tg. In
                        the period 1995 to 1999, CO2
                        emissions form fossil fuel combustion
                        in western Europe increased by 4.5%,
                        in the United States by 6.3%, in
                        Japan by 3.0%, and in India by 8.8%.




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                                                                (B) CH4 in China, 1990 to 2000.
                                 Concluding Remarks

                        1.   Research activities continue to increase
                                - North American Carbon Program
                                - Climate modeling enhancement
                                - Regional climate change studies

                        2.   U.S. Government Plans
                                 - Enhanced support for research
                                    (13 Federal agencies involved)
                                 - Research technology to help in mitigation
                                    (e.g. Hydrogen car)
                                 - Support Earth Observation Summit
                                    (July 31, 2003)

                        3.   We’re on a LONG road…



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