University of California Water Resources Center

This project implemented the initial phase of California-2100 (Cal21), which is aimed at making and evaluating high resolution estimates of climate change over California out to the year 2100. The initial WRC component of this project has been focused on evaluating how well regional climate models reproduce the variations of important components of the water budget for California, and estimating the effects of the increases over the past century in irrigation in California on regional climate, especially snow accumulation. The results show that global warming has a large effect on precipitation, snow water, surface temperature, low level winds and soil moisture They also show in summer that irrigation has a strong effect on the differences between recent and past conditions in maximum temperature, surface latent and sensible heat fluxes, surface moisture, and surface humidity.