1. Image courtesy of NASA/GSFC

2. Global Environmental Change: Technology and the Future of Planet Earth
Eugene S. Takle, PhD, CCM
Professor of Atmospheric Science
Department of Geological and Atmospheric Sciences
Professor of Agricultural Meteorology
Department of Agronomy
Iowa State University
Ames, Iowa 50011
Globalization Course
Cedar Rapids Iowa
19 October 2007

3. Outline Changes in atmospheric carbon dioxide Radiative forcing
Simulations of global climate and future climate change
Climate change and the scientific process
Four components for addressing climate change
Except where noted as personal views or from the ISU Global Change course, 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.

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

28. 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 (

31. Antarctica
Greenland
Ice Volume
Cold
Warm
Climate

32. Hansen, Scientific American, March 2004

34. 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.

35. 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

36. 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

37. 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

38. 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

39. IPCC Fourth Assessment Report Summary for Policy Makers

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

41. 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

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

43. IPCC Fourth Assessment Report Summary for Policy Makers

44. IPCC Fourth Assessment Report Summary for Policy Makers

45. “Warming Hole” DTmax (JJA)
A feature that corresponds to later 20th century trends. Not seen in GCMs. Linked to mesoscale circulation.
DTmax (JJA) ˚C
Pan, Z., R. W. Arritt, E. S. Takle, W. J. Gutowski, Jr., C. J. Anderson, and M. Segal, 2004: Altered hydrologic feedback in a warming climate introduces a “warming hole”. Geophys. Res. Lett.31, L17109, doi: /2004GL

46. Observed summer (June-July-August) daily mean temperature changes (K) between (Adapted from Folland et al. [2001]).

47. Precipitation minus Evaporation for Western US
(25N-40N, 95W-125 W)
R. Seager, et al.,
2007. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp

48. Precipitation minus Evaporation for Western US
(25N-40N, 95W-125 W)
R. Seager, et al.,2007. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp

49. Precipitation minus Evaporation for Western US
(25N-40N, 95W-125 W)
Colorado River Compact established, 1922
R. Seager, et al.,2007. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp

50. Exposing Anthropogenic Climate Change to Standard Scientific Evaluation
Methodological
Inductive (specific to general)
Deductive (general to specific)
Falsifiable (testable; does not rely on articles of faith)
Evidentiary : Strong consistency of evidence
Instrumental records (temperature, satellite obs)
proxy records (tree rings, lake sediments, bore holes, etc.)
Performance
Prediction
Provide useful advice
Inference to best explanation
All available evidence points towards role of human effects.
Community standards
Naomi Oreskes, 2007

51. 1970’s: Debate about Global Cooling: what to do?
Refer question to the National Academy of Sciences.

52. National Academy of Sciences
The NAS was signed into being by President Abraham Lincoln on March 3, 1863, at the height of the Civil War. As mandated in its Act of Incorporation, the NAS has, since 1863, served to "investigate, examine, experiment, and report upon any subject of science or art" whenever called upon to do so by any department of the government.

53. So what did the Academy say?
"Our knowledge of the mechanisms of climatic change is at least as fragmentary as our data…Not only are the basic scientific questions largely unanswered, but in many cases we do not yet know enough to pose the key questions”
Connolley, W. M., 1975: UNDERSTANDING CLIMATE CHANGE: A program for action. US National Academy of Sciences/National Research Council Report

54. Intergovernmental Panel on Climate Change (IPCC)
Created in 1988 by the World Meteorological Organization (UN) and the United Nations Environmental Programme
IPCC purpose is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature

55. NAS Assessment of IPCC Conclusions
“Greenhouse gases are accumulating in the Earth’s atmosphere as a result of human activities, causing surface air temperatures to rise and sub-surface ocean temperatures to rise”
“The IPCC’s conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue”
National Academy of Sciences Committee on the Science of Climate Change, 2001: Climate change science: An analysis of some key questions. National Academy Press.

56. IPCC AR4 (2007) Process
IPCC does not conduct its own research. It simply organizes teams of scientists to evaluate the current state of scientific knowledge
People from over 130 countries contributed to the IPCC Fourth Assessment Report over the previous 6 years.
These people included more than scientific expert reviewers, more than 850 contributing authors, and more than 450 lead authors

57. IPCC Fourth Assessment Report (2007)
“The understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] W m-2.”

58. IPCC AR4 Conclusions Warming of the climate system is unequivocal.
Most of (>50% of) the observed increase in globally averaged temperatures since the mid-20th century is very likely (confidence level >90%) due to the observed increase in anthropogenic (human) greenhouse gas concentrations.
Hotter temperatures and rises in sea level "would continue for centuries" even if greenhouse gas levels are stabilized, although the likely amount of temperature and sea level rise varies greatly depending on the fossil intensity of human activity during the next century.

59. IPCC AR4 Conclusions
The probability that this is caused by natural climatic processes alone is less than 5%.
World temperatures could rise by between 1.1 and 6.4 °C (2.0 and 11.5 °F) during the 21st century and that:
Sea levels will probably rise by 18 to 59  cm (7.08 to 23.22 in).
There is a confidence level >90% that there will be more frequent warm spells, heat waves and heavy rainfall.

60. IPCC AR4 Conclusions
There is a confidence level >66% that there will be an increase in droughts, tropical cyclones and extreme high tides.
Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium.
Global atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased markedly as a result of human activities since and now far exceed pre-industrial values over the past 650,000 years

61. 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

62. 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

63. 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

64. 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

65. 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

66. 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

67. D. Herzmann, Iowa Environmental Mesonet

68. D. Herzmann, Iowa Environmental Mesonet

69. D. Herzmann, Iowa Environmental Mesonet

70. D. Herzmann, Iowa Environmental Mesonet

71. D. Herzmann, Iowa Environmental Mesonet

72. D. Herzmann, Iowa Environmental Mesonet