Global Climate Change: Past and Future Le Moyne College Syracuse, New York February 3, 2006...
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Transcript of Global Climate Change: Past and Future Le Moyne College Syracuse, New York February 3, 2006...
Global Climate Change: Past and Future
Le Moyne CollegeSyracuse, New York
February 3, 2006
Department of Meteorology and Earth and Environmental Systems Institute (ESSI)
Penn State University
`The balance of evidence suggests that there is a
discernible human influence on global climate '
Intergovernmental Panel on Climate Change (United Nations), Second Assessment Report, 1996
`There is new and stronger evidence that most of the warming observed over
the last 50 years is attributable to human activity'
Intergovernmental Panel on Climate Change (United Nations), Third Assessment Report, 2001
THE DATA
Climatic Research Unit (‘CRU’), University of East Anglia
Surface Temperature Changes
Greenhouse Gases and WarmingCO2
Related?
TREE RINGS
CORALS
ICE CORES
VARVED LAKE SEDIMENTS
HISTORICAL DOCUMENTS
RECONSTRUCTED GLOBAL
TEMPERATURE PATTERNS
Reconstructed Surface Temperatures
Climate Change 2001: The Scientific Basis, Houghton, J.T.,
et al. (eds.), Cambridge Univ. Press, Cambridge, 2001
Reconstructions of Northern Hemisphere mean temperatures
for the last 1000 years and instrumental record (black line)
From “Wikipedia”
CLIMATE MODELS
The climate represents a coupled system consisting of an atmosphere, hydrosphere,
biosphere, and cryosphere
General Circulation Models take into
account the full three-dimensional structure of
the atmosphere and ocean
This alone doesn’t guarantee that they should do a good job in describing climate change!
GCMs do a fairly good job of
describing the seasonal cycle in
surface temperature
January Temp (observations)
January Temp (model)
Modeled Internal Natural Variability Observations
INFLUENCE OF EXTERNAL FACTORS
The climate is governed by external factors, including the intensity of solar output and volcanic aerosols
and greenhouse gas concentrations
Solar Variations
The climate is governed by external factors, including the intensity of solar output and volcanic aerosols
and greenhouse gas concentrations
Volcanoes
The climate is governed by external factors, including the intensity of solar output and volcanic aerosols
and greenhouse gas concentrations
The climate is governed by external factors, including the intensity of solar output and volcanic aerosols
and greenhouse gas concentrations
GREENHOUSE EFFECT?
ENHANCED GREENHOUSE EFFECT?
SIMULATIONS OF CLIMATE CHANGE
Simulated Annual Global Mean Surface Temperatures
Climate Change 2001: The
Scientific Basis, Houghton, J.T., et
al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
Forced Model simulations
Simulated Annual Global Mean Surface Temperatures
Climate Change 2001: The
Scientific Basis, Houghton, J.T., et
al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
Forced Model simulations
Simulated Annual Global Mean Surface Temperatures
Climate Change 2001: The
Scientific Basis, Houghton, J.T., et
al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
Forced Model simulations
Climate Change 2001: The Scientific Basis, Houghton, J.T., et al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
Future Surface Temperatures Trends?
Possible Impacts:
North American Drought
1998 Global Temperature Pattern
El Nino and North American Drought
El Nino vs. North American Drought over the Past Century
Increased Drought La Nina
El NinoLess Drought
Courtesy of E.Cook
Katrina
(Aug 28 ’05)
Destructive Potential of
Atlantic Hurricanes
Possible Impacts:
Rita
(Sep 21 ’05)
Destructive Potential of
Atlantic Hurricanes
Possible Impacts:
Wilma
(Oct 19 ’05)
Destructive Potential of
Atlantic Hurricanes
Possible Impacts:
Hurricane Statistics
P. J. Webster, G. J. Holland, J. A. Curry, H.-R. Chang Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment, Science, 309, Issue 5742, 1844-1846 , 2005.
Climate Model Predictions
Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment, P. J. Webster, G. J. Holland, J. A. Curry, H.-R. Chang, Science, Vol 309, Issue 5742, 1844-1846 , 16 September 2005.
Climatological Surface Temperatures January
[source: NOAA Climate Prediction Center][source: NOAA Climate Prediction Center]
Surface Temperature Pattern January ’06
[source: NOAA Climate Prediction Center]
Surface Temperature Anomaly Pattern January ’06
[source: NOAA Climate Prediction Center]
Temperature Anomaly Pattern (January ’06)
Climate Change 2001: The Scientific Basis, Houghton, J.T., et al. (eds.), Cambridge Univ.
Press, Cambridge, 2001
CONCLUSIONS
•Recent global surface temperatures are unprecedented this century, and likely at least the past millennium
•It is difficult to explain the recent surface warming in terms of natural climate variability
•Recent surface warming is largely consistent with simulations of the effects of anthropogenic influence on climate
•Possible impacts of anthropogenic climate change this century include increased drought conditions in the western U.S. and more destructive Atlantic tropical storms and Hurricanes