Climate Systems Chapter 15. Clicker Question What is the approximate CO 2 content of the atmosphere?...
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Transcript of Climate Systems Chapter 15. Clicker Question What is the approximate CO 2 content of the atmosphere?...
Climate Systems
Chapter 15
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– 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 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 Cyclein 1000’s km3/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
• 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 large variation in global temperatures
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
• Carbon Cycle• Rock Cycle• Mantle Cycle• Greenhouse Gas• El Niño• La Niña
Climate Learning Goals• Atmosphere is in equilibrium with surface• Cycles and Systems
• 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 16Weathering, 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 16Weathering, Erosion,
Mass Wasting• Does weathering of rock remove or add
CO2 to the atmosphere? – A. Adds– B. Removes – C. No effect on CO2