1. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Global Climate Change and Regional Impacts: Are We Building the Right Kind of Drainage Structures to Handle Climate Change? Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa 50011 gstakle@iastate.edu

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  Implications for stream flow and nutrient loss  Summary

3. Carbon Dioxide and Temperature

4. 2004

5. Carbon Dioxide and Temperature 2004 2040

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

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

14. Observed summer (June-July-August) daily mean temperature changes (K) between 1976-2000 (Adapted from Folland et al. [2001]).

15. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

16. Hansen, Scientific American, March 2004

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

19. Source: National Center for Atmospheric Research

20. The planet is committed to a warming over the next 50 years regardless of political decisions

21. Source: Intergovernmental Panel on Climate Change, 2001 Report Amount of warming is in question, but all models project a warming

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

23. 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

24. 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

25. 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

26. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Climate Surprises  Breakdown of the ocean thermohaline circulation (Greenland melt water)  Breakoff of the West Antarctic Ice Sheet

27. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Regional Climate Change for the US Midwest  Observed and projected changes in climate  Impact on water quantity and water quality  Policy implications

28. Changes in Daily Maximum Temperature Projected for 2040 by a Regional Climate Model

29. Changes in Daily Minimum Temperature Projected for 2040 by a Regional Climate Model

30. “Warming Hole”  T max (JJA) ˚C

31. For the Midwest  Warming will be greater for winter than summer  Warming will be greater at night than during the day  A 3 o F 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

32. 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

33. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Soil Water Assessment Tool (SWAT)  Long-term, continuous watershed simulation model (Arnold et al,1998)  Assesses impacts of climate and management on yields of water, sediment, and agricultural chemicals  Physically based, including hydrology, soil temperature, plant growth, nutrients, pesticides and land management  Daily time steps

34. Validation of SWAT: Annual Stream Flow at Grafton, IL

35. Validation of SWAT: Monthly Stream Flow at Grafton, IL

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

37. 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

38. Comparison of Simulated Stream Flow under Climate Change with Various Model Biases

39. Relation of Runoff to Precipitation for Various Climates

40. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Regional Climate Modeling for Informing Policy on Water Quality  How does the combination of climate change and land use impact water quality?  Use nitrates and sediment as indicators  What alternative land management strategies will improve water quality?  What policies need to be implemented to achieve this water quality improvement?

41. Maquoketa Watershed

42. Scenario 1: all Agriculture Scenario 2: all Forest

43. Scenario 3: N. half Agric. and S. half Forest. Scenario 4: S. half Agric. and N. half Forest.

44. Scenario 5: Upper half Agric. and lower half Forest. Scenario 6: Lower half Agric. and upper half Forest.

45. Scenario 7: Main channel basins - Agric. Scenario 8: Main channel basins - Forest.

46. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Improving Regional Climate Models  Project to Intercompare Regional Climate Simulations  Transferability Working Group of GEWEX

47. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Summary Regional climate models demonstrate sufficient skill to be useful for driving some climate impacts assessment models for the purpose of informing policy makers and decision-makers of vulnerabilities and opportunities associated with future climate change

48. 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