Climate change may drive shifts in global agriculture that will affect remaining natural lands, with important consequences for the conservation of species and ecosystems. Wine production is an excellent model for examining this type of impact, because suitable climate is central to product quality and production is centered in Mediterranean climate regions that are all global biodiversity hotspots. Adaptation to climate change in existing vineyards may involve water use to ameliorate heat stress or drought, resulting in additional conservation issues. Global studies of wine, climate, and conservation have highlighted the need for more detailed regional analyses to better understand these complex multiple issues. Here we examine impacts of climate change on winegrape suitability in California and its possible implications for nature conservation and water use. Under two global climate models and two emissions scen- arios, winegrape suitability in California is projected to decline overall and to move into unde- veloped areas that provide important habitats for native species. Coastal and upslope areas retain and improve in suitability, respectively, while inland areas see the largest losses in suit- ability. Areas of declining suitability are regions in which heightened water use for vineyard adaptation may lead to declines in stream flow or conflicts with other water uses. Continued growth in global demand for wine and reduced production in areas of declining suitability will drive expansion into newly suitable areas, potentially impacting important species native to California. Existing vineyards in areas of declining suitability will likely need to adapt to remain viable. Advance planning for a changing climate and adaptation options that are not water intensive (e.g. vine orientation, trellising, or varietal switch) will help reduce potential water conservation issues in those areas.