Agriculture and climate change

1. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Agriculture and Climate
Change
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
gstakle@iastate.edu
Underwriting/Marketing Seminar, 30 March 2005

2. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Outline
 Evidence for global climate change
 Future atmospheric carbon dioxide concentrations
 Simulations of global climate and future climate
change
 Impacts of climate change for the US Midwest
 “Climate surprises”
 Social inequities and ethical issues
surrounding climate change
 Summary

3. Carbon Dioxide
and Temperature

4. Carbon Dioxide
and Temperature
2005

5. Carbon Dioxide
and Temperature
2005
2040
(375 ppm)
(440 ppm)

6. Carbon Dioxide
and Temperature
Stabilization at 550 ppm

7. Carbon Dioxide
and Temperature
“Business as Usual”
(fossil intensive)
2100

9. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Associated Climate Changes
 Global sea-level has increased 1-2 mm/yr
 Duration of ice cover of rivers and lakes decreased by 2 weeks in N.
Hemisphere
 Arctic ice has thinned substantially, decreased in extent by 10-15%
 Reduced permafrost in polar, sub-polar, mountainous regions
 Growing season lengthened by 1-4 days in N. Hemisphere
 Retreat of continental glaciers on all continents
 Poleward shift of animal and plant ranges
 Snow cover decreased by 10%
 Earlier flowering dates
 Coral reef bleaching
Source: Intergovernmental Panel on Climate Change, 2001 Report

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

11. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

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13. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

14. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

15. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

16. Hansen, Scientific American, March 2004
Mt. Pinatubo (1991)
El Chichon (1982)
Agung, 1963

17. Source: Jerry Meehl, National Center for Atmospheric Research

18. Source: National Center for Atmospheric Research

19. Source: National Center for Atmospheric Research
The planet is committed to
a warming over the next
50 years regardless of
political decisions

20. Source: Intergovernmental Panel on Climate Change, 2001 Report

21. 40% Probability
5% Probability
Source: Intergovernmental Panel on Climate Change, 2001 Report

22. Climate Change
Projected for 2100
Rapid Economic
Growth
Slower Economic
Growth

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

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

25. IPCC Summary for
Policy Makers
 An increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system

26. IPCC Summary for
Policy Makers
 An increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system
 Emissions of greenhouse gases and aerosols
due to human activities continue to
alter the atmosphere in ways that
are expected to affect the climate

27. IPCC Summary for
Policy Makers, cont’d
 Confidence in the ability of models to
project future climate has increased

28. IPCC Summary for
Policy Makers, cont’d
 Confidence in the ability of models to
project future climate has increased
 There is new and stronger evidence that
most of the warming observed over
the last 50 years is attributable
to human activities

29. IPCC Summary for
Policy Makers, cont’d
 Anthropogenic climate change will persist
for many centuries

30. IPCC Summary for
Policy Makers, cont’d
 Anthropogenic climate change will persist
for many centuries
 Further action is required to address
remaining gaps in information and
understanding

31. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Climate Surprises:
Low Probability but High-Impact Events
 Breakdown of the ocean thermohaline
circulation (Greenland melt water)
 Breakoff of the West Antarctic Ice Sheet

32. Climate
Cold Warm
0
Antarctica
Greenland

33. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

34. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Meltwater flows into
a large moulin on
Greenland and down to
the bedrock to "lubricate"
the sheet
BBC News: World Edition
http://news.bbc.co.uk/2/hi/science/nature/2558319.stm

37. For the Midwest
 Warming will be greater for winter than summer
 Warming will be greater at night than during the
day
 A 3oF rise in summer daytime temperature triples
the probability of a heat wave
 Growing season will be longer (8-9 days longer
now than in 1950)
 More precipitation
 Likely more soil moisture in summer
 More rain will come in intense rainfall events
 Higher stream flow, more flooding

38. Sub-Basins of the
Upper Mississippi
River Basin
119 sub-basins
Outflow measured
at Grafton, IL
Approximately one
observing station
per sub-basin
Approximately one
model grid point
per sub-basin

41. RegCM2 Simulation Domain
Red = global model grid point Green/blue = regional model grid points

42. Ten-Year Mean Monthly Stream Flow Generated by the
RegCM2 Regional Climate Model Driven
with HadCM2 Global Model Results for the
Contemporary and Future Scenario (2040s) Climate

43. Relation of Runoff to Precipitation
for Various Climates
More precip
goes to
streamflow in a
future climate

44. “Warming Hole”
DTmax (JJA)
˚C

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

46. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities

47. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities

50. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Impact on US Agriculture
(my speculations)
 The US is a large enough country at a high enough latitude that it will have
regional winners and losers
 Areas now marginal for agriculture may become less suitable
 Some areas now having abundant water but limited growing seasons may be
winners
 Areas with good soils and robust climate, like Iowa, may be impacted less
 The US Midwest may experience more variability from
year to year, which would make agricultural yields
more variable (flooding, water-logging, drought)
 Changes in consumption and agricultural production
in other nations may affect US agriculture more
than changes to US climate
 Environmental refugees?

51. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities

52. http://www.grida.no/climate/vital/37.htm

53. http://www.grida.no/climate/vital/38.htm

54. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities

55. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

56. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Sea-Water Innundation
Example: The Maldives
 Area: 115 square miles
 Population: 143,000
 Highest point: 20 ft above sea level

57. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural production
 Freshwater availability
 Sea-water innundation
 Intergenerational inequities

58. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Intergenerational Inequities
 Sustainable Development: “To meet the needs of
the present without compromising the ability of
future generations to meet their needs.”
 Energy sources?
 Non-renewable earth resources?
 Agricultural productivity?
 Fresh water supplies?
 Heavy metal contamination of soil
and water?

59. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Summary
 Climate change is real and we need to be doing
something about it
 The longer we wait, the fewer our options
 Regional patterns of warming will be complicated
 Climate surprises can’t be discounted
 Climate change will create regional
agricultural winners and losers
 Climate change carries ethical
implications

60. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
For More Information
 See my online Global Change course:
http://www.meteor.iastate.edu/gccourse
 Contact me directly:
gstakle@iastate.edu
http://www.meteor.iastate.edu/faculty/takle/