1. Climate Change Challenges in the Arizona-Sonora Border Region Arizona-Mexico Commission – Water Committee 2007 Arizona Summer Plenary Session Tucson, ArizonaJune 14, 2007 Gregg Garfin Climate Assessment for the Southwest Institute for the Study of Planet Earth University of Arizona

2. Climate Change Water Challenges in the Arizona-Sonora Border Region Increased temperatures: very likely Decreased precipitation: likely Potential direct impacts and concerns: Decreased water supply reliability Increased surface water evaporation Decreased hydropower production Reduced minimum flows for fish and estuaries Earlier peak flow timing Greater likelihood of extreme events: drought, flood

3. Climate Change Water Challenges in the Arizona-Sonora Border Region Potential indirect impacts and concerns: Increased water and energy demands for warm season cooling Amplified by urban heat islands Increased stress on ecosystems: Enhanced insect-related disturbances Fire  erosion  decreased water quality  enhanced threats to infrastructure Invasive species + fire + increased temperature  plant and animal migration  landscape transformation

5. 2000 2002 2002 Soildesiccation Soil desiccation Arizona DailyStar Arizona Daily Star Lake Powell’s decline J. Dohrenwend, USGS 2003 Southern California Wildfires New York Times Southwest U.S. forest die-off T. Degomez, UA Cooperative Extension

6. Mexico Ranching Impacts 1990s northern Mexico droughts 30% reduction in cattle inventory 1996: >300,000 cattle perished Cattle sold in U.S. market at depressed prices U.S.-Mexico tensions over tariffs, disease

7. Reservoir Levels 1999 Drought disaster declarations Costs > $350 million (source: CNN, May 21, 1999)

8. Cortez Vázquez, 2006 NADM Workshop

9. October-May Precipitation Sonora/Chihuahua José Villanueva Diáz, INIFAP, 2006 NADM Workshop

10. Radiation Balance The climate system redistributes heat and moisture

11. http://www.grida.no/climate/vitalafrica/english/09.htm

12. 380 Most rapid change in the last 10,000 years 280 CO2 Change in Perspective http://www.grida.no/climate/vital/02.htm

13. http://lwf.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html

14. Courtesy of Kelly Redmond, Western Regional Climate Center

16. Henry Diaz, NOAA ESRL Annual Temperature Change at 10,000 ft / 3,000 m – 1979-2004

17. Taken January 30, 2006 by Larry Martinez, USDA-NRCS: White Mountain Snowpack at 9,200 ft., near Mt. Baldy Wilderness (Normally 24” snowpack).

18. Stewart et al. 2005 Journal of Climate

21. IPCC 4 th Assessment: Working Group I, Chapter 11, Regional Projections

22. Lower latitudes tend to dry out during winter Tropical high pressure expands Jet stream retreats to the north

23. Change in Center of Mass in Streamflow Stewart et al., 2004 Climatic Change

24. Conservative Projection of Future Climate in the UCRB 11 models and 2 emissions scenarios downscaled to the Colorado River Basin Departures from 1950-1999 Annual average temperature Annual average precipitation Annual average runoff Christensen & Lettenmaier, 2006 9.0° 5.4°

25. Impacts to LCRB Christensen and Lettenmaier, 2006 April 1 SWE: 75% of average by 2040-2069 Releases to Lower Basin: drop below current annual releases 28-44% of years Delivery shortages: 21-38% of the time Average deliveries to Mexico: –85% to –94% of treaty agreement Power output: –20% of 1950-1999 average Decreased surface water supply reliability

26. Longer Heat Waves Diffenbaugh et al., 2005 Proceedings of the National Academy of Science

27. More Precipitation in Extremes Diffenbaugh et al., 2005 Proceedings of the National Academy of Science Arizona Daily Star

28. Victor Magaña, UNAM

30. Courtesy of Dr. Craig Allen, NPS Massive Forest Dieback

31. Courtesy of Univ. Arizona Laboratory of Tree-Ring Research http://www.ispe.arizona.edu/climas/learn/fire/ecological.html Post-Wildfire Erosion Courtesy of Ron Smallwood, Large Binocular Telescope Observatory, 2004 Fire

32. Current Realities: Changing demographics Population increases on both sides of the border Growing populations strain water resources and raise demand for energy Altered land-use patterns increase vulnerability Courtesy of Dr. Robert Varady, Udall Center for Studies in Public Policy

33. Recommendations to address Climate Change Water Challenges Enhanced bi-national climate monitoring SMN, NIDIS, AHIS Citizen scientists, Rainlog Centers for Arizona-Sonora bi-national research and outreach Capacity building initiatives Border Climate Summary Arizona-Sonora drought preparedness To optimize decision-making: strong cooperation between institutions affected by climate and those that manage water and land

34. Gregg Garfin Climate Assessment for the Southwest Institute for the Study of Planet Earth gmgarfin@email.arizona.edu 520-622-9016 www.ispe.arizona.edu/climas http://www.climate.noaa.gov/cpo_pa/risa/