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The Anthropocene

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Fossil fuel consumption adds another 25 Tg/ yr,(25,000 kg) which as NOX is ... In the Year 2050 some Red States Become Blue. Permafrost Regions ... – PowerPoint PPT presentation

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Title: The Anthropocene


1
The Anthropocene
  • Quaternary Seminar
  • Fall, 2005
  • Bud J. Benneman

2
Anthropocene
  • Anthropocene The term refers to the most recent
    period of the Earths history starting in the 18
    th century when activities of the human race
    first began to have a significant global impact
    on ecosystems and climate.
  • The term Anthropocene was coined by Paul Crutzen.

3
Anthropogenic Global Warming
  • Describes an increase in the average temperatures
    of the Earths atmospheric and oceans.
  • The terms global warming or anthropogenic global
    warming are used to describe the theory that
    increasing temperatures are the result of
    strengthening greenhouse effect caused primarily
    by human actions.

4
Major Topics
  • Ruddimans Hypothesis.
  • Importance of Green House Gases.
  • Explanations of pre-industrial Green
  • House Gases (GHGs).
  • Industrial Revolutions I and II.
  • Major Greenhouse Gases.
  • Population.

5
Major Topics
  • Industrial Revolution III.
  • Stream Flow Modification.
  • The Nitrogen Cascade.
  • Solar Radiation and Global Dimming.
  • Melting of the Permafrost.
  • The Colorado River
  • Sea Surface Temperatures.
  • Climate Modeling
  • Paper Discussion (Joos et al., 2004)

6
Ruddimans Hypothesis
  • Humans discovered agriculture 12,000 years ago.
  • Prior to religion, writing, and great cities
    humans started alerting climate.
  • Ruddiman puts forth the hypothesis that through
    the discovery of plant and animal domestication
    the Anthropocene began 8,000 years ago.

7
Ruddimans Anthropocene
  • CO2 and CH4 are the two most talked about Green
    House Gases.
  • CH4 Cycles may be linked to monsoon intensity
    (greater wetland extent) and increases in CH4
    concentrations in the Vostock Ice cores. They
    measured monsoon maxima at 10, 80, 105, and 130
    kyr BP, which corresponds to interglacial
    periods.

8
Important Concepts
  • Temperature does not control CH4. what is
    important is that temperature controlled the
    aerial extent of wetlands, which releases
    methane.
  • Earths orbital variations such as 23,000 orbital
    precession. The tilt varies and changes, thus in
    10,500 years the Earth will have a summer tilt
    when it is closer to the sun resulting in a net
    increase in solar radiation (northern
    Hemisphere).

9
Percessional- Wobble Like a TopNorthern
Hemisphere v Southern Hemisphere Facing the Sun
Change in the direction of the Axis of rotation
relative to the Sun
Southern
Northern
25,800 Year Cycle
10
Percessional- Wobble
11
Obliquity Tilt Variation 2.4 Degree
Milder Winters Cooler Summers
Colder Winters Warmer Summers
40,000 Year Cycle
12
Eccentricity
Current 365.4 day orbit around the Sun
Day of the CCSN Field Trip The Earth Was Here
Fall
Summer
Sun
Winter
100,000 Orbital variation eccentricity around the
Sun
Spring
This drawing is not to scale, its not even close
so dont worry man
13
  • These Earth orbital variations result in normal
    climate change.
  • Humans through the introduction of agriculture
    changes and Greenhouse Gases such as CO2 and
    CH4 have resulted in a continuation of a warming
    period.
  • According to Ruddiman, we have delayed a
    glaciation.

14
  • Methane follows the insolation until the
    Holocene.
  • CO2 also varies with the orbital cycles
  • CO2 reaches a maximum at the height of the
    interglacial
  • From Ice core evidence it is apparent that the
    last 10,000 have been different than the last
    100,000

15
  • There is a seemingly anomalous trend in which CO2
    levels start to increase 8,000 years ago when
    they should be decreasing.

16
Hare
Tortoise
8000
17
  • 9,000-7,800

7,800-6800
9,000-7,800
6,800-5700
gt10,000
Mediterranean Sea
9,000-7,800
10,000-9000
18
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19
Solar Radiation
Natural CH4 Trend
20
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21
Carbon Based Fuels
  • Industrial revolution I and II has caused an
    increase in CO2
  • Industrial Revolution III India and China will
    contribute additional CO2

22
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23
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24
Carbon Dioxide Variations
25
Major Greenhouse Gases
26
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27
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28
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29
Industrial Revolution III
  • China and India are in the process of
    industrializing.
  • The catalyst for this industrialization is
    western investment, inexpensive labor, reduced
    regulations, innovations in communication, and
    transportation.

30
World Population 2004
31
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32
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33
Stream Flow Modification
  • 75 of the worlds rivers have seen some kind of
    stream flow modification.
  • Some rivers that had continuous flow now run dry
    every year.
  • Other river systems, can no longer provide the
    necessary energy to disperse sediment up and down
    the coast.

34
Colorado Delta
Santa Clara Wetland
35
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36
Mississippi Delta Spring Runoff
37
Stream Flow Modifications
  • Some river systems can no longer sweep the
    fine-grained organic matter and mud out of their
    estuaries systems.
  • Reservoir storage and impacts of river systems
    varies according to climate.
  • This variation results in difficult modeling
    concepts (Syvitski, 2002)

38
Stream Flow Modification
  • Other rivers that were one dominated by suspended
    load have become bedload-rivers through the
    trapping efficiency of upstream reservoirs.
  • Amazon River has an increase in sediment load due
    to deforestation and runoff.
  • Amazon soil erosion is a unique and a large
    problem.

39
Nitrogen Cascade
  • More nitrogen is fixed synthetically and applied
    as fertilizers than in all ecosystems combined
    120Tg/Yr vs 90Tg (McNiell, 2004).
  • Of the 120 Tg/year (280,000kg), 100 Tg is wasted,
    discharged into rivers, lakes and subsurface
    reservoirs.
  • The result is eutrophication of surface waters.

40
  • Fossil fuel consumption adds another 25 Tg/
    yr,(25,000 kg) which as NOX is highly reactive ,
    causing photochemical ozone formation.
  • The disturbance of the Nitrogen cycle also leads
    to the microbiological production of the
    greenhouse gas NO.
  • Oceans, worldwide are releasing increased amounts
    of NO (Galloway, 2002).

41
Galloway, 2002
42
Global Warming and Water Resources of Southern
Nevada
  • Increased temperature without the influences of
    melting ice equates to dryer conditions.
  • Warmer Dryer v. Cooler Wetter

43
1927 Compact
1944 Amendment
44
1927 1944 Allocations
Odd Years 1961-1970 Glen Canyon Reservoir Filling
45
Gunnison River Tributary to Colorado River
46
Colorado River Compact Site
47
1,138.47 ft Elevation as of 10-22-05
48
Southern Nevada allocation 300,000 MAF/year, Use
475,000 due to return credits
49
Climate Modeling
  • Significant amount of variation with respect to
    reconstructions of climate and future
    projections.
  • Considerable amount of variables.
  • Climate modeling is the best alternative for
    future climate predictions.
  • In this case the past climates are the key to the
    future.

50
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51
Classon, 2002
52
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53
Discussion of Paper
  • Differences Between this paper and Ruddiman.
  • In specific reference to upward revisions of land
    use change.
  • Carbon emissions by anthropogenic land use
    changes v. Oceanic Sediment interaction.

54
Paper Discussion Continued
  • Can the coral reef buildup scenario account for
    CO2 buildup of 40 ppm?
  • Do climate forcing models account for CO2
    Holocene increases, and how reliable are these
    models?

55
Hare
Tortoise
8000
56
  • 9,000-7,800

7,800-6800
9,000-7,800
6,800-5700
gt10,000
Mediterranean Sea
9,000-7,800
10,000-9000
57
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58
Carbon Dioxide Variations
59
Response to Atmospheric CO2
Figure-1
60
Precipitation and Temperature Anomalies
Figure-2
61
Changes in Land Availability for Plant Growth
Figure-3
62
Simulated Changes in Terrestrial Carbon
Figure-4
63
Simulated CO2 v. Holocene Ice Core
Figure-5
64
Figure-6 Contribution of CaCO3
65
Figure-7 CO2 Increase By CaCO3 Compensation
66
Figure-8 Reconstructed v Simulated
Reconstructed v Simulated Atmospheric CO2
67
Figure-9 Simulated Delta Carbon 13
68
Figure-10 LGM Holocene Changes
69
Figure-11 Biome Types
70
Figure-12 Biome Distribution
71
End of Anthropogenic Climate Change
Punta Gaspareno Baja California, Sur. N22o4722
72
Solar Radiation
  • Widespread decline in solar radiation from
    1960-1990.
  • This global decline in solar radiation referred
    to as Global Dimming may have masked some of
    the greenhouse effect and related impacts.
  • Since the late 1980s the Northern Hemisphere has
    seen a widespread brightening.

73
Global Brightening
  • The Brightening seems to conenside with the
    greenhouse signals in the late 1990s
  • Whereas, the decline in in solar energy could
    have counterbalanced the increase in down-welling
    of long-wave energy from the enhanced greenhouse
    effect.
  • Now beginning to see the true effects of
    greenhouse gases (Wild et al.,2005).

74
  • Time series of mean annual solar radiation
  • AAll Sky conditions BClear Sky

75
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76
Melting of the Permafrost
  • Rising temperatures in permafrost regions may
    release tons of carbon stored in permafrost
    soils.
  • This will influence global climate change.
  • Permafrost soils have an average carbon content
    of 2.5 which, equates to 500 gigatons of carbon,
    2.5 times that of all the rainforest combined.

77
Permafrost Siberia
78
Increasing Sea Surface Temperatures
  • Important in the Caribbean and Gulf of Mexico.
  • Increased incidence, and intensity of tropical
    storm.

79
Sea Surface Temperature
80
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81
Melting of Ice
  • Since industrialization glaciers have retreated.
  • Sea level increase have impacted low lying costal
    areas.

82
Sea Level Increases
83
Increased Incidence of Costal Flooding
84
Higher Tidal Surges
85
If Current Trends Continue
86
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87
In the Year 2050 some Red States Become Blue
88
Permafrost Regions
  • This carbon is a relatively liable product of
    plant roots that were incorporated from a
    productive steppe vegetation during the
    Pleistocene.
  • Upon thaw, microbes will begin converting the
    carbon into CO2 under aerobic conditions, and
    into methane under anaerobic conditions (Nisbet,
    2002).
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