Transcript 15Climate

Chapter 15
Climate Systems
Clicker Question
• What is the approximate CO2
content of the atmosphere?
– A. 0.004% (40 ppm)
– B. 0.04% (400 ppm)
– C. 0.4% (4000 ppm)
– D. 4% (40,000 ppm)
– E. 40% (400,000 ppm)
Clicker Question
• What is the approximate CO2
content of the atmosphere?
– A. 0.004% (40 ppm)
– B. 0.04% (400 ppm)
– C. 0.4% (4000 ppm)
– D. 4% (40,000 ppm)
– E. 40% (400,000 ppm)
Clicker Question
• The CO2 content of the atmosphere
has increased by more than 20% in
the past 50 years.
– A. True
– B. False
Clicker Question
• The CO2 content of the atmosphere
has increased by 19% in the past 50
years.
– A. True
– B. False
Systems?
• What is a system?
• Geologic phenomena are complex.
• All processes are related to, and
interact with, other processes.
• So it is useful to think of geologic
processes as systems or cycles.
Earth Systems
• Earth Interior Systems
– Mantle Convection and Plate Tectonics
– Core Convection and Magnetic Field
– Rock Cycle (weathering & metamorphism)
• Atmospheric/Biospheric Systems
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Hydrologic Cycle
Ocean Cycles (Circulation and El Niño)
Carbon Cycle (CO2 in atmosphere)
Oxygen Cycle
Earth Interior Systems
• Rock Cycle
– Igneous-Weathering-Sedimentation-
Metamorphism
• Mantle Cycle
– Mantle Convection, Crust Formation,
and Subduction = Plate Tectonics
– Water Cycling
• Core Convection
– Magnetic Field - Ozone shield
Earth Interior Systems:
Deep Water Cycle
• Ocean crust hydrates on ocean
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bottom.
Crust and lithosphere subduct.
>90% of water is returned at arc
volcanoes
1 to 10% of this water goes deep.
This water is returned at mid ocean
ridges.
Earth Interior Systems:
Deep Water Cycle
• 0.2% H2O in subducting crust is
sufficient to recycle the oceans once
in 4 Gy.
• Oceans (0.025% of Earth mass) is
maintained by a deep cycle of H in
high pressure minerals.
• H solubility in rock is responsible for
the style of plate tectonics.
Atmospheric/Biospheric
Systems: Human Impact
• Hydrologic Cycle
– Evaporation - Transport - Precipitation - Flow
• Ocean Cycles
– Global Circulation & El Niño
• Carbon Cycle (Greenhouse Gas)
– CO2 - Photosynthesis - Carbon -
Carbonates
• Oxygen Cycle
– O2 in atmosphere is biogenic
– Incompatible with methane (CH4)
Hydrologic Cycle
3
in 1000’s km /y
Carbon Cycle: Natural Sources and Sinks
Carbon Cycle: Anthropogenic
Carbon Cycle CO2
Carbon Cycle
Carbon Cycle
Warming
• Sea Level Rise
– Thermal Expansion of water
– Melting Glaciers
• Increased Storm Intensity
Warming:
Vulnerable US Cities
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New Orleans
Houston
Corpus Christi
Mobile
Orlando
Miami
Climate Cycles:
Eccentricity
Climate Cycles: Tilt
Climate Cycles: Precession
Continental Drift and
Ocean Circulation
Ocean Cycle: El Niño
Continental Drift
Past Climate History
•
18O/16O
Variation in Ice Cores
– Oxygen isotopes are fractionated by
evaporation and precipitation.
– The vapor prefers the lighter isotope.
– Cold global temperatures deplete 18O in
ice and enrich it in ocean water.
– Isotope variation can be measured in ice
cores and in ocean sediments.
• CO2 variation can be measured in gas
bubbles in ice.
• Both methods provide evidence of
Atmospheric/Biospheric
Systems: Human Impact
• Hydrologic Cycle
– Evaporation - Transport - Precipitation - Flow
• Ocean Cycles
– Global Circulation & El Niño
• Carbon Cycle (Greenhouse Gas)
– CO2 - Photosynthesis - Carbon -
Carbonates
• Oxygen Cycle
– O2 in atmosphere is biogenic
– Incompatible with methane (CH4)
Earth Systems Terms
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Carbon Cycle
Rock Cycle
Mantle Cycle
Greenhouse Gas
El Niño
La Niña
Climate Learning Goals
• Atmosphere is in equilibrium with surface
• Cycles and Systems
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Hydrologic Cycle: Surface, shallow, deep
Ocean circulation: heat transport
Carbon Cycle: Sources and sinks
Oxygen Cycle: Where does it come from?
Rock Cycle: weathering, transport.
Climate Learning Goals
• What is a greenhouse gas?
• How does it trap heat?
• How much CO2 do we have now?
• What are main sources and sinks?
• Do we have a record of past CO2?
• Do we have a record of Earth temperatures?
Next Chapter 16
Weathering, Erosion,
Mass Wasting
• Does weathering of rock remove or
add CO2 to the atmosphere?
– A. Adds
– B. Removes
– C. No effect on CO2
Next Chapter 16
Weathering, Erosion,
Mass Wasting
• Does weathering of rock remove or
add CO2 to the atmosphere?
– A. Adds
– B. Removes
– C. No effect on CO2