To build public support for adapting to and mitigating climate change, it will be necessary to develop greater awareness of a broad set of biophysical and socioeconomic factors that influence agricultural vulnerability and resilience. First, the study developed a spatially explicit agricultural vulnerability index for California derived from 22 climate, crop, land use, and socioeconomic variables. Results of the agricultural vulnerability index suggest that the Sacramento‐San Joaquin Delta, the Salinas Valley, the corridor between Merced and Fresno, and the Imperial Valley merit special consideration due to their high agricultural vulnerability. The underlying factors contributing to vulnerability and resilience differ among these regions, indicating that future studies and responses could benefit from adopting a contextualized “place based” approach. As an example of this approach, the research team summarized the findings from a recent study on climate change adaptation in Yolo County. The Yolo County study consists of: (1) an econometric analysis of crop acreages under future climate change projections; (2) a hydrologic model of the Cache Creek watershed that simulates the impact of future climate and crop acreage projections on local water supplies; (3) a countywide inventory of agricultural greenhouse gas (GHG) emissions and how it might be used to inform local Climate Action Plans; (4) a survey of farmers’ views on climate change, its impacts and what adaptation and mitigation strategies they might be inclined to adopt; and (5) an urban growth model that evaluates various future development scenarios and the impact on Yolo County farmland and GHG emissions. Since farmland throughout the state is vulnerable to urbanization, the study also used urban growth projections for 2050 to examine the possible impacts on statewide agricultural production, land use patterns, and soils. Lastly, the study examined two on‐farm case studies (Fetzer/Bonterra Vineyards and Dixon Ridge Farms) that highlight the possible benefits of innovative agricultural practices (for example, vineyard carbon storage and renewable energy production from crop residues) that link adaptation and mitigation. 

This place‐based case study in an agricultural county in California’s Central Valley focused on the period of 2010–2050, and dealt with biophysical and socioeconomic issues related to both mitigation of greenhouse gas (GHG) emissions and to adaptation to an uncertain climate. In the past 100 years, changes in crop acreage has been more related to crop price and availability of irrigation water than to growing degree days during summer, and in fact, summer temperatures have increased less than winter temperatures. Econometric analysis indicated that warmer winters, as projected by Geophysical Fluid Dynamics Laboratory‐Bias Corrected Constructed Analog during 2035–2050, could result in less wheat acreage, more alfalfa and tomato acreage, and slight effects on tree and vine crops. The Water Evaluation and Planning (WEAP) model showed that these econometric projections did not reduce irrigation demand under either the B1 or A2 scenarios, but a diverse, water‐efficient cropping pattern combined with improved irrigation technology reduced demand to 12 percent below the historic mean.   Collaboration during development of Yolo County’s Climate Action Plan showed that nitrous oxide (mainly from nitrogen fertilizers) was the main source (≅40 percent) of agricultural emissions. Emissions from cropland and rangeland were several orders of magnitude lower than urbanized land per unit area. A survey distributed to 570 farmers and ranchers achieved a 34 percent response rate. Farmers concerned about climate change were more likely to implement water conservation practices, and adopt voluntary GHG mitigation practices. Use of the urban growth model (UPlan) showed that channeling much or all future urban development into existing urban areas will increase ecosystem services by preserving agricultural land and open space, immensely reducing the Yolo County’s GHG emissions, and greatly enhancing agricultural sustainability