Climate Change Challengesin the Arizona-Sonora

Border Region

Arizona-Mexico Commission – Water Committee2007 Arizona Summer Plenary Session

Tucson, Arizona June 14, 2007

Gregg GarfinClimate Assessment for the SouthwestInstitute for the Study of Planet EarthUniversity of Arizona

Climate Change Water Challenges in the Arizona-Sonora Border Region

Increased temperatures: very likelyDecreased 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

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

2000

2002

20022002SoilSoil desiccationdesiccation

Arizona DailyArizona Daily StarStar

Lake Powell’s declineLake Powell’s declineJ. Dohrenwend, USGSJ. Dohrenwend, USGS

2003 Southern California Wildfires2003 Southern California WildfiresNew York TimesNew York Times

Southwest U.S. forest die-offSouthwest U.S. forest die-offT. Degomez, UA Cooperative ExtensionT. Degomez, UA Cooperative Extension

Mexico Ranching

Impacts1990s 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

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

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80

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Year

# o

f H

ea

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Beef Cattle

# of Pigs

Reservoir Levels Reservoir Levels in Sonora

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Jul-9

9

Oct

-99

Jan-

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pr-0

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Jul-0

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Apr

-01

Jul-0

1

Oct

-01

Jan-

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Jan-

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-03

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-03

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Jul-0

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Time

% C

apac

ity

Obregon

Calles

1999 Drought disaster declarationsCosts > $350 million (source: CNN, May 21, 1999)

Cortez Vázquez, 2006 NADM Workshop

October-May Precipitation Sonora/Chihuahua

José Villanueva Diáz, INIFAP, 2006 NADM Workshop

Radiation Balance

The climate system redistributes heat and moisture

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

380

Most rapid change in the last 10,000 years

280

CO2 Change in Perspective

http://www.grida.no/climate/vital/02.htm

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

Calendar Year

1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

An

nu

al

Tem

pe

ratu

re (

F )

41

42

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48

Upper Colorado Basin Mean Annual Temperature.Units: Degrees F. Annual: red. 11-year running mean: blue

Data from PRISM: 1895-2005.

WRCC / CEFA NOAA WestmapCourtesy of Kelly Redmond, Western Regional Climate Center

Water Year ( End Year )

1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Wa

ter

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ar

Pre

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in

ch

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)

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Upper Colorado River Water Year Precipitation.October through September. Units: Inches.Data from PRISM. Blue: annual. Red: 11-yr mean.

WRCC CEFANOAA WestmapCourtesy of Kelly Redmond, Western Regional Climate Center

Henry Diaz, NOAA ESRL

Annual Temperature Change at 10,000 ft / 3,000 m – 1979-2004

Taken January 30, 2006 by Larry Martinez, USDA-NRCS: White Mountain Snowpack at 9,200 ft.,

near Mt. Baldy Wilderness (Normally 24” snowpack).

Stewart et al. 2005 Journal of Climate

Stewart et al. 2005 Journal of Climate

Stewart et al. 2005 Journal of Climate

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

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

Change in Center of Mass in Streamflow

Stewart et al., 2004 Climatic Change

ConservativeProjection of Future Climate in the UCRB

11 models and 2 emissions scenarios downscaled to the Colorado River Basin

Departures from1950-1999

Annual average temperature

Annual average precipitation

Annual average runoff

Christensen & Lettenmaier, 2006

9.0°

5.4°

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

Longer Heat WavesDiffenbaugh et al., 2005

Proceedings of the National Academy of Science

More Precipitation in ExtremesDiffenbaugh et al., 2005Proceedings of the National Academy of Science

Arizona Daily Star

Victor Magaña, UNAM

Victor Magaña, UNAM

Courtesy of Dr. Craig Allen, NPS

Massive Forest Dieback

Courtesy of Univ. Arizona Laboratory of Tree-Ring Researchhttp://www.ispe.arizona.edu/climas/learn/fire/ecological.html

Post-Wildfire Erosion

Courtesy of Ron Smallwood, Large Binocular Telescope Observatory, 2004 Fire

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

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

Gregg GarfinClimate Assessment for the SouthwestInstitute for the Study of Planet Earth

gmgarfin@email.arizona.edu520-622-9016

www.ispe.arizona.edu/climashttp://www.climate.noaa.gov/cpo_pa/risa/