Following the release of the IPCC Fifth Assessment Report, and realizing the likely impact on California water and agricultural sectors, we review key concepts in the climate change lexicon in the context of California agriculture. There are a range of modeling approaches used to study the benefits of water basin- and/or farm-level adaptations, including hydrological, crop simulation, economic programming, and econometric models. Given the central role of farmer and institutional responsiveness, how do recent agro-economic assessments suggest that specific adaptations may improve economic welfare and reduce vulnerability? What is economically efficient adaptation in the short and long-run? What are the limits to the agricultural sector’s adaptive capacity?