Modeled Regional Climate Change in the Hydrologic Regions of California: a CO sub(2) Sensitivity Study

• Published in: Journal of the American Water Resources Association 2004-06, Vol.40 (3), p.591-591
• Main Authors: Snyder, Mark A, Sloan, Lisa C, Bell, Jason L
• Format: Article
• Language: English
• ISSN: 1093-474X

Using a regional climate model (RegCM2.5), the potential impacts on the climate of California of increasing atmospheric CO sub(2) concentrations were explored from the perspective of the state's 10 hydrologic regions. Relative to preindustrial CO sub(2) conditions (280 ppm), doubled preindustrial CO sub(2) conditions (560 ppm) produced increased temperatures of up to 4 degree C on an annual average basis and of up to 5 degree C on a monthly basis. Temperature increases were greatest in the central and northern regions. On a monthly basis, the temperature response was greatest in February, March, and May for nearly all regions. Snow accumulation was significantly decreased in all months and regions, with the greatest reduction occurring in the Sacramento River region. Precipitation results indicate drier winters for all regions, with a large reduction in precipitation from December to April and a smaller decrease from May to November. The result is a wet season that is slightly reduced in length. Findings suggest that the total amount of water in the state will decrease, water needs will increase, and the timing of water availability will be greatly perturbed.