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GLOBAL WARMING: CAUSES, EFFECTS, AND MITIGATION

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Title: GLOBAL WARMING: CAUSES, EFFECTS, AND MITIGATION


1
GLOBAL WARMING CAUSES, EFFECTS, AND MITIGATION
  • David P. Chynoweth
  • Dept. of Agricultural and Biological Engineering
  • University of Florida

2
GLOBAL WARMING
  • Greenhouse Gases
  • Effects
  • Evidence for
  • Remedies
  • Socio-Economic Issues
  • Significance of Methane
  • Kyoto Conference

3
SOURCES OR CAUSES OF INCREASES IN GASES (1)
  • Carbon Dioxide
  • Fossil fuel combustion
  • Deforestation
  • Methane
  • Flooded soil crops (e.g. rice)
  • Fossil fuel mining
  • Ruminants
  • Landfills
  • Organic wastes
  • Human stimulated eutrophication

4
SOURCES OR CAUSES OF INCREASES IN GASES (2)
  • Nitrogen Oxides
  • Nitrogen fertilizers
  • Fossil fuel combustion
  • Chlorofluorohydrocarbons
  • Release of refrigerant CFCs

5
CONCENTRATIONS AND WARMING POTENTIAL OF
GREENHOUSE GASES
6
CHANGES IN ATMOSPHERIC C02 AND EARTHS
TEMPERATURE CHANGE
7
INCREASE IN ATMOSPHERIC METHANE CONCENTRATONS
8
WORLD CARBON EMISSIONS FROM FOSSIL FUEL BURNING,
1900-99
9
GLOBAL CARBON EMISSIONS PER PERSON, 1950-97, WITH
PROJECTIONS TO 2050
10
CARBON EMISSIONS FROM FOSSIL FUELBURNING BY
ECONOMIC REGION, 1950-98
11
CARBON EMISSIONS PER CAPITA, TOP TENEMITTING
NATIONS, 1996
12
CO2 EMISSIONS BY COUNTRY TOTAL, PER CAPITA, AND
PER GNP (1)
13
CO2 EMISSIONS BY COUNTRY TOTAL, PER CAPITA, AND
PER GNP (2)
14
(No Transcript)
15
UNCERTAINTIES IMPACTING DEGREE OF WARMING EXPECTED
  • Atmospheric sensitivity temperature associated
    with doubling of CO2 conc.
  • Earths carbon cycle
  • Projected CO2 emissions in the future
  • Methane lifetime
  • Projected growth of methane emissions
  • Effect of CFC substitutes
  • Equilibrium earth temperature in response to gas
    influence

16
Potential Effects of Global Warming
  • Elevated temperatures of the biosphere
  • melting of polar ice
  • increase in sea level (flooding of major cities)
  • increase of methane from permafrost
  • Weather extremes
  • more rainfall during shorter periods
  • more evaporation and soil moisture deficiencies
  • Ecosystem disruption
  • stress and death of vegetation
  • migration of animals
  • Human Health
  • heat stress
  • migration of disease vectors

17
SPECIFIC EFFECTS OF GLOBAL WARMING (2.7oC FROM
PRE-INDRUSTRIAL TO 2100) (1)
  • Sea levels rising by 0.5 1.5 m over the next
    few decades and several meters in the long term
  • More frequent weather extremes producing floods,
    avalanches, run-off water availability, soil
    erosion
  • Droughts, loss of soil moisture
  • Reduced precipitation in mid-latitude regions of
    N. America and Eurasia

18
SPECIFIC EFFECTS OF GLOBAL WARMING (2.7oC FROM
PRE-INDRUSTRIAL TO 2100) (2)
  • More stagnant air masses for longer time periods
  • Severe impact on agricultural productivity
    worldwide
  • Die off of unmanaged forests
  • Reduced stream flows
  • Increased mortality due to heat stress and spread
    of infectious diseases

19
FLOODING (75 M INCREASE IN OCEAN DEPTH)
20
EVIDENCE FOR GLOBAL WARMING (1)
  • Atmosphere CO2 levels have increased from 230 to
    250 ppm (30 since pre-industrial and during
    industrial age)
  • Atmospheric methane levels are increasing about
    1 per year
  • Temperature of the earth surface has increased by
    0.4oC
  • Temperature of ocean has increased by 0.5oC
  • October 6, 1997 was the hottest temperature on
    record for that time of the year
  • In 1995, 400 persons died of heat stroke in
    Chicago

21
EVIDENCE FOR GLOBAL WARMING (2)
  • Number of days with temperatures below freezing
    has dropped from 90 in 1990 to 15 in 1997.
  • Storm and drought conditions are greater than can
    be explained by normal weather fluctuations
  • 5-10 increase in precipitation in the 20th
    century
  • Floods in the U.S. and China have been 10x more
    frequent in the past 10 years
  • Ocean sea level has risen 0.5 cm in last decade,
    25 cm in last century
  • China plans to build one 1,000 MW power plant per
    month for the next four years
  • Coal energy releases twice as much CO2 as gas

22
EVIDENCE OPPOSING GREENHOUSE GAS GLOBAL WARMING
(1)
  • Temperature trends and climate models
  • Newer models are predicting lesser temperature
    increase trends
  • Increase in the earths surface has been far less
    during the past 150 years than the future trends
    predicted by models

23
EVIDENCE OPPOSING GREENHOUSE GAS GLOBAL WARMING
(2)
  • Natural climate change takes thousands of years
  • Science, October 2, 1998. Around 12,500 years
    ago, the temperature rose by more than 20oF in
    only 50 years.

24
EVIDENCE OPPOSING GREENHOUSE GAS GLOBAL WARMING
(3)
  • Emissions from the U.S. are the primary cause of
    greenhouse related warming
  • Science, October 16, 1998. The U.S. removes more
    carbon (about 2 billion tons) than it releases
    (about 1.5 billion tons) because of tremendous
    re-growth of eastern forests acting as carbon
    sinks.

25
EVIDENCE OPPOSING GREENHOUSE GAS GLOBAL WARMING
(4)
  • Nature, March 11, 2000. Overall, CO2 and
    temperature has remained fairly constant over the
    past 11,000 years. Temperature has been fairly
    stable. CO2 has varied greatly within normal
    limits.
  • Science, March 12, 1999. When the earth shifts
    from glacial to warm periods (every 100,000
    years), temperature increases are normal and
    precede releases of CO2. The link between human
    activity and warmer temperatures is therefore
    uncertain.

26
EARTHS CLIMATE HISTORY
  • Increases of 2.15.7oC are predicted due to
    greenhouse gases
  • A 1-1.5oC global average warming would represent
    a climate not experienced since the beginning of
    agricultural civilization (6,000 years ago)
  • A 1-2.5oC warming represents a climate not
    experienced since 125,000 years ago when small
    human communities existed Such a climate seemed
    to partially disintegrate the West Antarctic
    Shield, raising sea levels 5-7 m
  • A 3-4oC warming has not been experienced since
    humans appeared on Earth (2 million years ago).
    The last time Earth experienced such a climate
    was about 3-5 million years ago.

27
AVERAGE TEMPERATURE AT EARTH'S SURFACE 1866-1999
28
GLOBAL AVERAGE SEA SURFACE TEMPERATURE 1950-97
29
GLOBAL AVERAGE TEMPERATURE, 1950-99
30
MEAN TEMPERATURE ESTIMATES, PRELIMINARY IPCC
SCENARIOS, 1990-2100
31
REMEDIES FOR GLOBAL WARMING
  • Reduce use of fossil fuels
  • Reduce energy consumption
  • Replace fossil fuels with energy forms that dont
    release net carbon dioxide (e.g., solar, biomass,
    wind, hydroelectric, nuclear)
  • Remove carbon dioxide from combustion gases
  • Increase standing crop of carbon-fixing plants
  • reduce deforestation
  • Reduce anthropogenic sources of methane (flooded
    crops, releases fossil fuel mining, landfills,
    organic wastes, ruminants)
  • Reduce release of N from fertilizers and
    combustion

32
SOCIOECONOMIC ISSUES
  • Developed countries use most of the fossil
    energy.
  • U.S. has 4 of the world population and uses 25
    of the energy
  • Developing countries use about 10 of energy per
    capita as the U.S.
  • In the U.S., energy use is 36 for building, 32
    for transportation, and 32 for industry
  • Power plants waste energy ( a 400 MW plant wastes
    800 MW of heat energy)
  • Developed countries have developed on the basis
    of use of energy and deforestation. How can we
    ask emerging countries not to do the same?

33
IMPORTANCE OF METHANE IN MITIGATION OF GLOBAL
WARMING (1)
  • principal greenhouse gas
  • concentrations are rising
  • potent contributor to global warming
  • short-term impact of mitigation
  • a few sources account for large portion of
    emissions

34
IMPORTANCE OF METHANE IN MITIGATION OF GLOBAL
WARMING (2)
  • stabilization of concentrations would have
    similar impact as stabilization of carbon
    dioxide
  • mitigation would have significant environmental
    and economic benefits
  • technologies are available for reduction

35
SOURCES AND SINKS OF ATMOSPHERIC METHANE
36
NATURAL SOURCES OF ATMOSPHERIC METHANE
37
ANTHROPOGENIC SOURCES OF ATMOSPHERIC METHANE
38
POTENTIAL GLOBAL METHANE EMISSIONS REDUCTIONS BY
SOURCE
39
ANTHROPOGENIC METHANE EMISSIONS FROM HIGHEST FIVE
COUNTRIES
40
ESTIMATES OF LANDFILL METHANE EMISSIONS FROM
DIFFERENT COUNTRIESA
41
METHANE SOURCE FLUXES OF HIGH UNCERTAINTY
  • decaying hardwood of live trees
  • termites and other wood-eating insects
  • anthropogenic stimulated eutrophication
  • landfills (underestimated)

42
ENERGY POTENTIAL FROM BIOMASS AND WASTES IN THE
U.S.
43
U.S. CROPLAND NEEDED TO DISPLACE U.S. FOSSIL FUELS
44
COST ESTIMATES OF BIOMETHANE FROM ENERGY CROPS
45
EFFECT OF CARBON TAX ON METHANE PRICES
current price
46
KYOTO CONFERENCE (1)
  • December 10, 1997
  • 1500 delegates from 160 countries
  • Goal to arrive at legally binding treaty for
    global warming mitigation
  • Most developed countries would increase emissions
    by 20 with a business-as-usual policy

47
KYOTO CONFERENCE (2)
  • Pre-conference Goals by Country by 2010
  • European Community, -15 C release
  • Japan, -15
  • U.S., -3
  • Australia, 18 (Howard reducing to 4 would
    cost 68 million dollars and tens of thousands of
    jobs.)
  • Post-conference Goals
  • Developed Countries, -5
  • Australia, 8
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