Water availability, degree days, and the potential impact of climate change on irrigated agriculture in California

We use the geo-referenced June Agricultural Survey of the U. S. Department of Agriculture to match values of individual farms in California with a measure of water availability as mediated through irrigation districts, and degree days, a nonlinear transformation of temperature, controlling for other influences on value such as soil quality, to examine the potential effects of climate change on irrigated agriculture in California. Water availability strongly capitalizes into farmland values. The predicted decrease in water availability in the latest climate change scenarios downscaled to California can therefore be expected to have a significant negative impact on the value of farmland.