Aerial view of Parker Dam and hydroelectric equipment on the border between Arizona and California. Photo: BWBImages / Getty

A changing climate has already begun to transform California. In the past decade, the state has experienced persistent droughts, intense and sprawling wildfires, and average temperature increases that exceed 2°C in some regions.

To respond to these escalating impacts, California needs to plan pro-actively, not only within sectors but across them. This is especially important when it comes to water and energy, which are particularly intertwined in California.

For three years, SEI has modeled both water and energy systems in California, in order to inform the creation of climate-resilient infrastructure and policies. This work – funded by the U.S. Department of Energy, together with the University of California and the Swedish International Development Cooperation Agency – is part of a research and development partnership between the U.S. and China called the U.S./China Clean Energy Research Center for Water-Energy Technologies (CERC-WET).

In this study, researchers examined a number of scenarios, relative to a Policy Baseline Scenario, and then ran 20 different climate projections to examine the water and energy system vulnerabilities in California across different climates.

This report outlines the results of that modeling. It shows that reaching California’s climate targets will require policy-makers to plan for a future where water is scarce and weather more extreme — and to understand the state’s vulnerability across a range of economic, political and demographic shifts.