1. Climate Change: Understanding the Science and Monitoring Local Consequences
Eugene S. Takle, PhD, CCM
Professor of Atmospheric Science
Department of Geological and Atmospheric Sciences
Professor of Agricultural Meteorology
Department of Agronomy
Faculty Director, University Honors Program
Iowa State University
Ames, Iowa 50011
Big Bluestem Chapter
Audubon Society
Ames, IA
17 May 2007

2. Image courtesy of NASA/GSFC

3. Outline Changes in atmospheric carbon dioxide Radiative forcing
Simulations of global climate and future climate change
Four components for addressing climate change
Climate change for Iowa and the Midwest: adaptation strategy
Except where noted as personal views or from the ISU Global Change course or the Iowa Environmental Mesonet, all materials presented herein are from peer-reviewed scientific reports

4. CO2, CH4 and temperature records from Antarctic ice core data
Source: Vimeux, F., K.M. Cuffey, and Jouzel, J., 2002, "New insights into Southern Hemisphere temperature changes from Vostok ice cores using deuterium excess correction", Earth and Planetary Science Letters, 203,

5. CO2, CH4 and temperature records from Antarctic ice core data
Source: Vimeux, F., K.M. Cuffey, and Jouzel, J., 2002, "New insights into Southern Hemisphere temperature changes from Vostok ice cores using deuterium excess correction", Earth and Planetary Science Letters, 203,
Pattern repeats about every 100,000 years
Natural cycles

6. IPCC Third Assessment Report

7. Carbon Dioxide and Temperature
2007
380 ppm

8. Carbon Dioxide and Temperature
2050
550 ppm

9. Carbon Dioxide and Temperature
“Business as Usual”
950 ppm

10. Carbon Dioxide and Temperature
“Business as Usual”
950 ppm ?

12. Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.

13. Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

14. Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

16. IPCC Fourth Assessment Report Summary for Policy Makers

17. At present trends the imbalance = 1 Watt/m2 in 2018
El Chichon (1982)
Agung, 1963
Mt. Pinatubo (1991)
At present trends the imbalance = 1 Watt/m2 in 2018
Hansen, Scientific American, March 2004

18. NASA photographs show the minimm Arctic sea ice concentration in 1979 at left and in 2003.Satellite passive microwave data since 1970s indicate a 3% decrease per decade in arctic sea ice extent.

19. Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent.
(Illustration from NASA) (

20. Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

21. Impact of a 1-m rise in sea level on low-lying areas
Kennedy Space
Center
Impact of a 1-m
rise in sea level
on low-lying areas
Projected sea-level rise
In 21st century:
0.5 to 1.0 m
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

23. Hansen, Scientific American, March 2004

25. Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations.

26. Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations.
Natural cycles

27. Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations.
Not Natural

28. Highly Likely Not Natural
Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations.
Highly Likely Not Natural
Not Natural

29. Source: Jerry Meehl, National Center for Atmospheric Research
From Jerry Meehl
This slide shows the time evolution of globally averaged surface air
temperature from multiple ensemble simulations of 20th century climate
from the NCAR Parallel Climate Model (PCM) compared to observations.
The simulations start in the late 19th century, and continue to the year
The temperature scale at left is in degrees Centigrade, and
temperature anomalies are calculated relative to a reference period
averaged from 1890 to The black line shows the observed data, or
the actual, recorded
globally averaged surface air temperatures from the past century. The
blue and red lines are the average of four simulations each from the
computer model. The pink and light blue shaded areas depict the range
of the four simulations for each experiment, giving an idea of the
uncertainty of a given realization of 20th century climate from the
climate model. The blue line shows the average from the four member
ensemble of the simulated time evolution of globally average surface air
temperature when only "natural" influences (solar variability and
volcanic eruptions) are included in the model. Therefore, the blue
line represents what the model says global average temperatures would
have been if there had been no human influences. The red line shows the
average of the four member ensemble experiment when natural forcings AND
anthropogenic influences (greenhouse gases including carbon dioxide,
sulfate aerosols from air pollution, and ozone changes) are included in
the model. Note that this model can reproduce the actual, observed data
very well only if the combined effects of natural and anthropogenic
factors are included. The conclusion that can be drawn is that
naturally occuring influences on climate contributed to most of the
warming that occurred before WWII, but that the large observed
temperature increases since the 1970s can only be simulated in the model
if anthropogenic factors are included.
This confirms the conclusion of the IPCC Third Assessment Report that
most of the warming we have observed in the latter part of the 20th
century has been due to human influences.
Source: Jerry Meehl, National Center for Atmospheric Research

30. IPCC Fourth Assessment Report Summary for Policy Makers

31. Energy intensive Energy conserving Reduced Consumption
IPCC Fourth Assessment Report Summary for Policy Makers

32. Energy intensive Energy conserving Reduced Consumption
The planet is committed to a warming over the next 50 years regardless of political decisions
IPCC Fourth Assessment Report Summary for Policy Makers

33. Energy intensive Energy conserving Mitigation Possible Adaptation
Reduced Consumption
Energy conserving
Possible
Mitigation
Necessary
Adaptation
IPCC Fourth Assessment Report Summary for Policy Makers

34. IPCC Fourth Assessment Report Summary for Policy Makers

35. IPCC Fourth Assessment Report Summary for Policy Makers

37. Four-Component Approach for Addressing Climate Change
Mitigation policies:
Example: reduction in GHG emissions
Adaptation (long-term):
Example: Developing Iowa’s competitive economic advantage
Adaptation (short-term):
Example: redefining climate “normals” when needed and scientifically justified
Scenario planning for Iowa’s “Katrina”:
Example: Multi-year drought, recurrent floods, combination of both; drought and wildfire
EST personal view

38. Climate Adaptation(Short-Term)
If a meteorological variable began departing from its long-term background near or after 1970 it may be related to the radiation imbalance and thereby has a better chance than not of continuing its new trend over the next 5-10 years.
EST personal view

39. Projected Changes for the Climate of Iowa/Midwest (My tentative assessment)
Longer frost-free period (high)
Higher average winter temperatures (high)
Fewer extreme cold temperatures in winter (high)
More extreme high temperatures in summer (medium)
Higher nighttime temperatures both summer and winter (high)
More (~10%) precipitation (medium)
More variability of summer precipitation (high)
More intense rain events and hence more runoff (high)
Higher episodic streamflow (medium)
Longer periods without rain (medium)
Higher absolute humidity (high)
Stronger storm systems (medium)
Reduced annual mean wind speeds (medium)
Follows trend of last 25 years and projected by models No current trend but model suggestion or current trend but models inconclusive

40. D. Herzmann, Iowa Environmental Mesonet

41. D. Herzmann, Iowa Environmental Mesonet

42. D. Herzmann, Iowa Environmental Mesonet

43. D. Herzmann, Iowa Environmental Mesonet

44. D. Herzmann, Iowa Environmental Mesonet

45. D. Herzmann, Iowa Environmental Mesonet

46. D. Herzmann, Iowa Environmental Mesonet

47. “Warming Hole” DTmax (JJA)
A feature that corresponds to later 20th century trends. Not seen in GCMs. Linked to mesoscale circulation. ˚C
DTmax (JJA)

48. North America Regional Climate Change Assessment Program
Linda O. Mearns, National Center for Atmospheric Research
Principal Investigator
Raymond Arritt, William Gutowski, Gene Takle, Iowa State University
Erasmo Buono, Richard Jones, Hadley Centre, UK
Daniel Caya, OURANOS, Canada
Phil Duffy, Lawrence Livermore National Laboratories, USA
Filippo Giorgi, Jeremy Pal, Abdus Salam ICTP, Italy
Isaac Held, Ron Stouffer, NOAA Geophysical Fluid Dynamics Laboratory, USA
René Laprise, Univ. de Québec à Montréal, Canada
Ruby Leung, Pacific Northwest National Laboratories, USA
Linda O. Mearns, Doug Nychka, Phil Rasch, Tom Wigley, National Center for Atmospheric Research, USA
Ana Nunes, John Roads, Scripps Institution of Oceanography, USA
Steve Sain, Univ. of Colorado at Denver, USA
Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA

49. Summary
Climate change of the past 35 years is not consistent with natural variations over the last 400,000 years
Evidence clearly shows that radiative forcing due to anthropogenic greenhouse gases has contributed over half of the warming of the last 35 years
Mitigation efforts, although urgently needed, will have little effect on global warming until the latter half of the 21st century
Adaptation strategies should be developed for the next 50 years
Recent trends and model projections should be used to develop adaptation strategies for the next 10 years
EST personal view

50. For More Information Or just Google Eugene Takle
For peer-reviewed evidence supporting everything you have seen in this presentation, see my online Global Change course:
Contact me directly:
Current research on regional climate and climate change is being conducted at Iowa State Unversity under the Regional Climate Modeling Laboratory
North American Regional Climate Change Assessment Program
For this and other climate change presentations see my personal website:
Or just Google Eugene Takle

51. 6 March 2007 The Sunspot Cycle