Climate Simulation of the latest Permian: Implications for Mass Extinction

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Climate Simulation of the latest Permian
Implications for Mass Extinction

• Jeffrey T. Kiehl
• National Center for Atmospheric Research

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Outline

• The Permian-Triassic Mass Extinction
• Simulating the Climate of the Latest Permian
  Implications for Marine Mass Extinction
• Simulating the Chemical State of the Latest
  Permian Implications for Terrestrial Mass
  Extinction
• What About the Future?

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Christopherson (2000)
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Berner (2005)
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Erwin et al. (2002)
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Late Permian Geologic Conditions

• Pangea continental formation
• Large Igneous Provinces in Siberia (16X106 km3 of
  basalt, 5X106 km2 in area, 0.4-3 km in
  thickness), 700,000 years in duration
• Sea level transgression through the P-T boundary
  into the early Triassic (Erwin et al. 2002)
• Bolide Impact?
• Methane Hydrates?
• Oxygen 17

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Erwin(2006)
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Changes Across P-T Boundary

• Marine Life (95)
• Late Permian Plethora of Benthic Life, Early
  Triassic benthic life rare (dark sediments with
  pyrite deposits)
• Terrestrial Life (70)
• Late Permian tetrapod faunas reached high levels
  of complexity, Early Triassic shows loss of
  tetrapods, flora also dramatically effected
• Marine and Terrestrial Changes Coincident in Time
• Implications of global ocean anoxia

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Jin et al. (2000)
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Changes Across P-T Boundary

• Dramatic Shift in ?18O ratio of 6 o or a
  global rise of 6C
• Sharp Negative Excursion in ?13C from 4 o to -2
  o (which cannot be explained by extinction of
  life or volcanic CO2 emissions)
• Implies Global Warming and Large Input of 12C

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Simulating the Climate of the Latest Permian
Implications for Marine Mass Extinction
Kiehl, J.T. and C.A. Shields (2005), Climate
simulation of the latest Permian, Geology, 33,
757-760.
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Late Permian Boundary Conditions

• Solar Constant 2.1 Reduction of Present,
  Eccentricity of 0, Obliquity 23.5 (Gibbs et al.
  2002)
• CO2 level 10 X (Kidder Worsley, 2003, Berner,
  2005)
• Topography/Bathymetry (Ziegler et al. 1997)
• Ocean Floor Flat at 4000m

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Equilibrium?
Be aware when things are out of balance. Tao
Te Ching 53
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Global Annual Mean Energy Budget
Permian coupled model run for 2700 years to
new equilibrium state
Forcing of 10X increase in CO2 and
Permian paleogeography
CCSM3 T31X3
Global Annual Mean Surface Temperature
??Tsgt 8C
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Global Results
Permian Permian
N -0.026 Wm-2
?Ts 8.0 C (6-10 C)
?SST 5.2 C
?Ts(lnd) 12.8 C
?P 0.33 mmd-1
Ts(lndmax) 44.2 (37.1) C
Ts(lndmin) -7.2 (-56.4) C
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Permian ENSO
North Panthalassic Oscillation
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Present 1XCO2 10XCO2
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Permian MOC
Present MOC
Sv
Sv
Warm high latitude waters prevent formation of
deep overturning
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Inefficient mixing in Permian ocean
indicative of anoxia
Kiehl and Shields (2005)
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Ocean Oxygen Distribution
Brown et al. (1989)
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1XCO2
10XCO2
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1XCO2 AGE
10XCO2 AGE
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Permian 1 Reduction 10X to 1XCO2 Simulation
1.9XCO2
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1 CO2 Transient Simulation
Increasing CO2
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Implications for Marine Extinction

• Globally warm world shuts down high latitude
  pathways for surface water to reach ocean depth,
  this is apparently a stable solution
• Combined with lower solubility and lower
  atmospheric oxygen, implies low O2 levels at
  depth -gt global anoxia

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Simulating Chemical State of the Latest Permian
Implications for Terrestrial Mass Extinction
Lamarque, J.-F., J.T. Kiehl, C.A. Shields, B.A.
Boville, and D.E. Kinnison (2006) Modeling the
response to changes in tropospheric methane
concentration application to the
Permian-Triassic Boundary, Paleoceanography,
21,PA3006.
Lamarque, J.-F., J.T. Kiehl, and J.J. Orlando
(2006) The role of hydrogen sulfide in a
Permian-Triassic boundary ozone collapse,
Geophysical Res. Lett.in press
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Increase in Surface UV-B
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Heat Index
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H2S
OH
O3
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Chemistry Conclusions

• Massive injection of CH4 at the P-T boundary
  could potentially lead to a collapse in ozone
• Ozone collapse implies a 7 fold increase in
  surface UV-B
• Increase in CH4 leads to significant additional
  surface warming
• Massive release of H2S leads to O(10) fold
  decrease in OH, which leads to large CH4 lifetime
  (250 years)
• This longer CH4 lifetime means ozone destruction
  will occur for lower levels of CH4 emission (210
  GtC)

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CO2 from Volcanic Large Igneous Provinces
additional methane?
Global warming (10oC)
Warm Stratified Oceans Inefficient Mixing
Global Ocean Anoxia Mass Marine Extinction
CH4 Clathrate Release
Large Increase in Atmospheric CH4
Large H2S Emission
Large Reduction In Atmospheric OH
Impact on Atmospheric Chemistry
Collapse of Atmospheric Ozone Increase in UV-B
possible if large enough methane
increases methane lifetime
Mass Extinction of Terrestrial life
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What About the Future?
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North Atlantic 2000m Ideal Age 1 per year
increase in CO2
3XPresent
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THE END
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The Upcoming Pangea