![Page 1: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/1.jpg)
Insights into Climate Dynamics from Paleoclimate Data
Michael E. MannDepartment of Environmental Sciences
University of Virginia
Richard Foster Flint SymposiumDynamical Paleoclimatology
In Honor of the Memory of Barry SaltzmanYale University, New Haven, CT
November 3, 2001
Interannual Through Millennial Timescales
![Page 2: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/2.jpg)
OVERVIEW
•The Instrumental Record
•Proxy indicators and paleoclimate reconstructions
•Model/Data comparisons
•Conclusions
![Page 3: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/3.jpg)
Collaborators• Rob Allan• Ray Bradley• Keith Briffa• Ed Cook• Curt Covey• Tom Crowley• Heidi Cullen• Rosanne D’Arrigo• Tom Delworth• Chris Folland• Malcolm Hughes
•Malcolm Hughes•Phil Jones•David Karoly •Tim Osborn•Jonathan Overpeck•David Rind•Scott Rutherford•Gavin Schmidt•Drew Shindell•Ron Stouffer•Anne Waple
![Page 4: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/4.jpg)
•The Instrumental Record
•Proxy indicators and paleoclimate reconstructions
•Model/Data comparisons
•Conclusions
![Page 5: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/5.jpg)
Instrumental Surface Temperature Record
Grayshaded: 1902-1993
Checkboard: 1854-1993Climatic Research Unit (‘CRU’), University of East Anglia
![Page 6: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/6.jpg)
Instrumental Surface Temperature Record
“Niño3” El Niño
![Page 7: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/7.jpg)
Climatic Research Unit (‘CRU’)University of East Anglia
Instrumental Surface Temperature Record
![Page 8: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/8.jpg)
Instrumental Surface Temperature Record
Climate Change 2001: The Scientific Basis, Houghton, J.T., et al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
![Page 9: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/9.jpg)
Five leading patterns of global temperature variation during the 20th century.
Instrumental Surface Temperature Record
Mann, M.E., Bradley, R.S., Hughes, M.K., Global-Scale Temperature Patterns and Climate Forcing Over the
Past Six Centuries, Nature, 392, 779-787, 1998.
![Page 10: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/10.jpg)
•The Instrumental Record
•Proxy indicators and paleoclimate reconstructions
•Model/Data comparisons
•Conclusions
![Page 11: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/11.jpg)
TREE RINGS
![Page 12: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/12.jpg)
CORALS
![Page 13: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/13.jpg)
ICE CORES
![Page 14: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/14.jpg)
VARVED LAKE SEDIMENTS
![Page 15: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/15.jpg)
HISTORICAL DOCUMENTS
![Page 16: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/16.jpg)
tree-ring; + PCs of dense tree-ring networks, ice core C coral Early instrumental/historical (temperature) Early instrumental/historical (precipitation)
Annual Resolution Proxy Climate Indicators
![Page 17: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/17.jpg)
Baffin Island Canada Sediment Core
Hughen et al, Holocene 10, 1: 9-19 (2000).
Fisher et al (eds. Jones, P. D., Bradley, R. S. & Jouzel, J.) (Springer-Verlag Berlin Heidelberg, Berlin, 1996).
Ice CoreMongoliaTree Ring
D'Arrigo, R. et al, Geophysical Research Letters 28, 543-546 (2001).
Annual Resolution Proxy Climate Indicators
![Page 18: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/18.jpg)
INSTRUMENTAL TEMPERATURE
RECORD
GLOBAL PROXY
CLIMATE RECORDS
Annual Resolution Proxy Climate Indicators
![Page 19: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/19.jpg)
Five leading patterns of global temperature variation during the 20th century.
Instrumental Surface Temperature Record
Mann, M.E., Bradley, R.S., Hughes, M.K., Global-Scale Temperature Patterns and Climate Forcing Over the
Past Six Centuries, Nature, 392, 779-787, 1998.
![Page 20: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/20.jpg)
Reconstructed Surface Temperatures
![Page 21: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/21.jpg)
Reconstructed Surface Temperatures
Mann, M.E., Bradley, R.S., Hughes, M.K., Global-Scale Temperature Patterns and Climate Forcing Over the
Past Six Centuries, Nature, 392, 779-787, 1998.
![Page 22: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/22.jpg)
Reconstructed Surface Temperatures
VERIFICATION
![Page 23: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/23.jpg)
Reconstructed Surface Temperatures
Climate Change 2001: The Scientific Basis, Houghton, J.T.,
et al. (eds.), Cambridge Univ. Press, Cambridge, 2001
![Page 24: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/24.jpg)
Instrumental Surface Temperature Record
“Niño3” El Niño
![Page 25: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/25.jpg)
Cold-season Nino3 index
Reconstructed Surface Temperatures
Climate Change 2001: The Scientific Basis, Houghton, J.T.,
et al. (eds.), Cambridge Univ. Press, Cambridge, 2001
![Page 26: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/26.jpg)
•The Instrumental Record
•Proxy indicators and paleoclimate reconstructions
•Model/Data comparisons
•Conclusions
![Page 27: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/27.jpg)
Modeled Natural Variability Observations
![Page 28: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/28.jpg)
Climate Forcings
Anthropogenic
Greenhouse Gases
Industrial Aerosols
![Page 29: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/29.jpg)
Natural
1000 1200 1400 1600 1800 2000
Volcanism
Solar
Climate Forcings
![Page 30: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/30.jpg)
Relationship between Northern Hemisphere Temperature and Potential Predictors
Volcanism
Greenhouse Gases
Temperature
Mann, M.E., Bradley, R.S., Hughes, M.K., Global-Scale Temperature Patterns and Climate Forcing Over the
Past Six Centuries, Nature, 392, 779-787, 1998.
Solar Irradiance
![Page 31: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/31.jpg)
Simulated Annual Global Mean Surface Temperatures
Climate Change 2001: The
Scientific Basis, Houghton, J.T., et
al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
HADCM3 Coupled Ocean-Atmosphere Model
![Page 32: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/32.jpg)
Science
![Page 33: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/33.jpg)
Climate Change 2001: The
Scientific Basis, Houghton, J.T., et
al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
Future Surface Temperatures Trends
![Page 34: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/34.jpg)
Trend in NAO in past couple decades explains enhanced recent warming in certain regions of Northern Hemisphere
North Atlantic Oscillation
![Page 35: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/35.jpg)
“Little Ice Age”
North Atlantic Oscillation
![Page 36: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/36.jpg)
LIA winter cooling in Europe associated with
an NAO trend due to solar irradiance
changes, interacting w/ stratospheric
atmospheric dynamics and chemistry
NASA/GISS Model(Shindell et al, in press)
Empirical
North Atlantic Oscillation
![Page 37: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/37.jpg)
Atlantic Multidecadal Oscillation
![Page 38: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/38.jpg)
Atlantic Multidecadal Oscillation
![Page 39: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/39.jpg)
Atlantic Multidecadal Oscillation
![Page 40: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/40.jpg)
Atlantic Multidecadal Oscillation
A clear 50-70 year timescale signal apparently centered in the Atlantic is evident from
proxy-reconstructions of SST during the past few centuries
![Page 41: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/41.jpg)
The GFDL coupled model exhibits a robust 50-70 year timescale signal, which is insensitive to model
resolution
Atlantic Multidecadal Oscillation
![Page 42: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/42.jpg)
ModelObservations
Atlantic Multidecadal Oscillation
![Page 43: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/43.jpg)
Atlantic Multidecadal Oscillation
The signal in the model represents a modulation
of the intensity of the North Atlantic THC with
oceanic feedbacks
Signal is oceanic in origin, but is modified
by the atmosphere
![Page 44: Insights into Climate Dynamics from Paleoclimate Data Michael E. Mann Department of Environmental Sciences University of Virginia Richard Foster Flint](https://reader035.vdocument.in/reader035/viewer/2022062313/56649cf45503460f949c2e0e/html5/thumbnails/44.jpg)
CONCLUSIONS
•Proxy-based reconstructions of Hemispheric temperature variations over past millennium are consistent with model-based estimates of both forced and internal climate variability
•20th century warming is inconsistent with natural climate variability, but can be explained by anthropogenic influence on climate
•Little Ice Age temperature reconstructions consistent with enhancement of NAO-type pattern in response to past solar variations produced in recent model simulation
•Internal multidecadal pattern of climate variability consistent with intrinsic model of ocean-atmosphere variability evident in long control simulations of coupled ocean-atmosphere models.