California Institute for Energy and Environment (CIEE)

A pair of projects is presented with the goal of improving understanding of future climate change in California. The first project assesses the ability of regional climate models and statistical downscaling to simulate the present climate in the State. This will provide understanding of the strengths and weaknesses of competing models and approaches. The second project provides probabilistic projections of future climate for use by decision-makers, impacts researchers, and others. The uncertainties in these projections will reflect uncertainty in knowledge of future climate perturbations (e.g., greenhouse gas emissions) as well as uncertainty in the response of the climate system. For the first (present climate) project, three options are presented which differ in the level of funding required ($500,000 to $2 million) and in the quantity and quality of information expected to result. The future-climate project assumes the existence of present climate simulations, which are needed as baselines. Thus, this project assumes that one of the more comprehensive present-climate project options will have been completed.