Along the North Coast, Arcata has been a leader in proactive planning for sea-level rise. In 2002, after witnessing increasing impacts from storms for several years, “we realized we couldn’t be putting our heads in the sand,” explained Mark André, the City’s director of environmental services. The City’s general plan now requires that potential sea-level rise be considered for all future development in coastal areas.

Arcata’s city planners created inundation maps, using various sea-level rise scenarios, to assess which areas were most vulnerable. They discovered that one key piece of infrastructure threatened was the City’s wastewater treatment plant at Arcata Marsh, so the levees protecting the buildings and treatment pond will be raised. Arcata has also been buying and restoring diked former salt marsh around Humboldt Bay to alleviate flooding, with the help of the Coastal Conservancy and others. “We were lucky to have bought out agricultural lands around the bay in the last decade,” André said.

In San Diego County, the San Diego Foundation’s Focus 2050 Study, published in November 2008, laid the groundwork for a comprehensive countywide response to expected climate change impacts, Hanak said. Using models and maps developed by researchers at the Scripps Research Institute in La Jolla, the study found that some of the region’s most popular beaches and surrounding neighborhoods could be flooded, including portions of La Jolla Shores and Mission, Coronado, and Imperial Beaches. The study also analyzed the impacts on the San Diego region of higher temperatures, water and energy shortages, increased wildfires, public health risks, and species loss.

In future studies, the Foundation will take a more detailed look at expected impacts to coastal infrastructure, from roads and railroads to San Diego’s port and airport, and military installations. “I think we’ve only begun to scratch the surface” of vulnerabilities, said Emily Young, the Foundation’s environment director. The Foundation is also funding technical assistance to local governments for climate change planning through the nonprofit ICLEI-Local Governments for Sustainability.

The City of Santa Cruz is just beginning work on a plan for adapting to the effects of climate change, including sea-level rise. Researchers at the University of California, Santa Cruz, will assess the city’s vulnerabilities, including potential economic impacts, and propose adaptation strategies. In the future, the City may collaborate with Santa Cruz and Monterey Counties on a regional approach for Monterey Bay, with the help of local universities and research centers, said Ross Clark, the City’s climate change action coordinator. “It would be really great if we could get some guidance from the state,” Clark said.

In response to the need for site-specific information and guidelines, the Ocean Protection Council (OPC), Coastal Commission, and California Energy Commission have been working to develop some. A new report by the Pacific Institute, funded by the OPC, Caltrans, and the Energy Commission, identifies areas that are most at risk for flooding and bluff erosion along the entire coastline and around San Francisco Bay (see sidebar).

“This information will help decision-makers and the public understand and explore the potential risks over the coming decades, the scope and extent of the problem, and how and where to allocate funds for responding to climate change,” said Christine Blackburn, OPC program manager.