Climate extremes in California agriculture

Changes in extreme events may represent an important component of climate change impacts on agricultural systems in California. This study considered the relative historical importance of extreme events, as measured by insurance and disaster payments. The causes for each main event for 1993-2007 were classified into general categories to compare the importance of dry vs. wet and hot vs. cold events. The study found that the most common cause of both insurance indemnity and disaster payments is excess moisture, followed by cold spells and heat waves. Climate change is likely to have different effects on the occurrence of each of these, for instance with frosts becoming less common while heat waves increase in frequency and duration. Resolving the overall net effect of changes in climate extremes will largely depend on improved understanding of future risks of excess rainfall and flooding events.