Southwest Regional Climate Hub and California Subsidiary Hub Assessment of Climate Change Vulnerability and Adaptation and Mitigation Strategies Authors: Jeanne Chambers, U.S. Forest Service; Helena Deswood, U.S. Department of Agriculture (USDA) Southwest (SW) Hub Coordinator; Emile Elias, USDA SW Hub Deputy Director; Kris Havstad, USDA-Agricultural Research Service Jornada Experimental Range Research Leader; Amber Kerr, California (CA) Sub Hub Coordinator; Albert Rango, Hub Director; Mark Schwartz, John Muir Institute of the Environment Director; Kerri Steenwerth, CA Sub Hub Co-Director; Caiti Steele, USDA SW Hub Deputy Director; Peter Stine, CA Sub Hub Co-Director; and Rachel Steele, National Climate Hubs Coordinator. Southwest Regional Climate Hub, 2995 Knox Street, Las Cruces, NM 88003. California Subsidiary Hub, 1 Shields Avenue, Davis, CA 95616. August 2015 Contributors: Our thanks to Shaun McKinney, NRCS; Luana Kiger, NRCS; Robert Tse, RD; Wendy Hall, APHIS; Marlene Cole, APHIS; Ricardo Lopez, USFS; Sharon Hestvik, RMA; Oscar Gonzales, FSA; and Molly Manzanares, FSA. We acknowledge ICF International for its contributions to the Greenhouse Gas Profile. Acknowledgments: We thank John Abatzoglou, Ruben Baca, Carolyn Cook, Dave DeWalt, Peg Gronemeyer, Amrith Gunasekara, Russ Henly, Estrella Herrera, Andrew Holguin, Ryann Smith, Scott Schrader, Jim Thorne, and Derrick Vinson. We appreciate the assistance of the following experts who reviewed selected crops: Malli Aradhya (stone fruit), Paul Brown (cotton), Greg Browne (almonds), Eli Carlisle (tomatoes), David Crowley (avocadoes), Oleg Daugovish (strawberries and broccoli), Louise Ferguson (citrus and pistachios), Tim Hartz (melons and carrots), Jim Hill (rice), Lee Jackson (small grains: wheat, barley and oats), Dan Kluepfel (almonds and stone fruit), Bruce Lampinen (walnuts), Bruce Linquist (rice), Joe Nuñez (carrots), Richard Percy (cotton), Carol Shennan (strawberries), Richard Smith (lettuce and onions/garlic), Scott Stoddard (tomatoes), Dianne Velasco (almonds), and Larry Williams (grapes). Any errors or omissions in this document remain the responsibility of the authors. We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model output. For CMIP the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. Edited by: Terry Anderson, ARS Suggested Citation: Elias, E., C. Steele, K. Havstad, K. Steenwerth, Chambers, J., H. Deswood, , A. Kerr, A. Rango, M. Schwartz , P. Stine, R. Steele, 2015: Southwest Regional Climate Hub and California Subsidiary Hub Assessment of Climate Change Vulnerability and Adaptation and Mitigation Strategies, T. Anderson, Ed., United States Department of Agriculture, 76 pp. Contributors: S. McKinney, L. Kiger, R. Tse, W. Hall, M. Cole, R. Lopez, S. Hestvik, O. Gonzales, M. Manzanares Contents Letter from the Regional Leads .................................................................................................................... 5 1. Introduction ........................................................................................................................................... 6 1.1. Description of the Region and Key Resources ............................................................................. 6 1.2. Demographics and Land Uses ....................................................................................................... 7 1.3. General Climate Conditions, Extremes, and Past Effects ............................................................. 7 Mainland States ..................................................................................................................................... 7 Hawai‘i .................................................................................................................................................. 9 1.4. Summary of Regional Climate Scenarios ..................................................................................... 9 Mainland States ..................................................................................................................................... 9 Hawai‘i ................................................................................................................................................ 11 2. Regional Agriculture’s Sensitivity to Climate Change and Adaptation Strategies ............................. 13 2.1. Cropping Systems Overview of Risks, Vulnerabilities, and General Adaptation Strategies ...... 13 Regional Issues for Southwest Cropping Systems .............................................................................. 13 Crop-Specific Vulnerabilities and Adaptation Strategies: California Specialty Crops ....................... 15 Crop-Specific Vulnerabilities and Adaptation Strategies: Southwest Field Crops ............................. 22 Crop-Specific Vulnerabilities and Adaptation Strategies: Hawai‘i .................................................... 26 2.2. Livestock Systems Overview of Risks, Vulnerabilities, and General Adaptation Strategies ..... 28 Effects of Climate Change on Southwestern Animal Agriculture ...................................................... 28 Regional Issues for Southwest Animal Agriculture and Rangeland Ecosystems ............................... 29 Adaptive Capacities ............................................................................................................................ 32 3. Forest Systems Overview of Risks, Vulnerabilities, and General Adaptation Strategies ................... 34 3.1. Effects of Climate Change on Southwestern Forests .................................................................. 34 Future Outlook for Southwest Forests ................................................................................................ 35 Regional Issues for Southwest Forest Systems ................................................................................... 36 Adaptation Strategies .......................................................................................................................... 37 Restoring Sustainable Forest Structure ............................................................................................... 38 3.2. Effects of Climate Change on Hawai‘i’s Forests ........................................................................ 39 4. Greenhouse Gas Emissions Profile from Agriculture and Forests, and Mitigation Opportunities within the Southwest Region ...................................................................................................................... 42 4.1. Soil Carbon Stock Changes......................................................................................................... 42 4.2. Nitrous Oxide Emissions in the Southwest Region .................................................................... 42 4.3. Livestock GHG Profile ............................................................................................................... 43 Enteric fermentation ............................................................................................................................ 44 Emissions from manure management systems ................................................................................... 44 4.4. Forest Carbon Stocks and Stock Changes ................................................................................... 45 4.5. Mitigation Opportunities ............................................................................................................. 46 Agricultural Soils ................................................................................................................................ 47 Land Retirement .................................................................................................................................. 47 Manure Management .......................................................................................................................... 47 Enteric Fermentation ........................................................................................................................... 48 5. USDA Programs ................................................................................................................................. 48 5.1. Natural Resources Conservation Service .................................................................................... 48 Role of NRCS in the Southwest .......................................................................................................... 49 NRCS California ................................................................................................................................. 50 5.2. U.S. Forest Service ..................................................................................................................... 51 National Forest System ....................................................................................................................... 51 Research and Development ................................................................................................................. 51 Regional Stations ...............................................................................................................................