Study: California’s Coast Highly Vulnerable To Sea Level Rise But Coastal Habitats Could Still Make It, If We Act
55% of current coastal habitat area in California could be lost to rising seas
Heather Gately
Email: heather.gately@tnc.org
Taylor Samuelson
Email: Taylor.Samuelson@scc.ca.gov
A new study from The Nature Conservancy and the California State Coastal Conservancy, Conserving California’s Coastal Habitat: A Legacy and a Future with Sea Level Rise finds that most of the total area of California’s coastal habitats, including beaches, marshes, and rocky intertidal areas famous for tide pools, are highly vulnerable to sea level rise. However, the study also provides a roadmap for California on how to take action so there will be as much coastal habitat statewide as there is today, even in the face of sea level rise and other stressors.
This study is the first of its kind to assess the sea level rise vulnerability of all coastal habitats along the entire coast of California, including the San Francisco Bay and Delta. Some habitats are more vulnerable than others. For example, beaches at the base of cliffs may be drowned by the ocean, habitats surrounded by developed land may not have the room they need to move inland as sea levels rise. But, with proper planning, other locations that aren’t coastal habitat today could be conserved and adapted to become habitat in the future. The report is also the first to provide scientists and planners with a set of strategies to adapt areas up and down the coast so that habitat that is lost to sea level rise in one location can be reestablished somewhere else.
Without taking action, the prognosis is troubling. The study quantifies the vulnerability of 40 different habitat types, finding that 55% of current habitat by total area across the state is highly vulnerable to five feet of sea level rise. That includes 60% of California’s iconic beaches, 58% of rocky intertidal habitat, 58% of marshes, and 55% of tidal flats. In addition, sea level rise will further stress populations of 39 rare, threatened, or endangered species, and 41,000 acres of public conservation lands are projected to be drowned by subtidal waters.
“It’s no secret that sea level rise will impact our coastline and coastal habitats, but now we know how much and where,” said Sarah Newkirk, Senior Coastal Project Director at The Nature Conservancy. “Our science shows that if we take purposeful action now, there is reason to think our children and grandchildren could still have California beaches and healthy coastal habitats to enjoy just as we do today.”
The study highlights key conservation strategies that would allow California to maintain much of its coastal habitat into the future and maps where these actions might be most usefully deployed, providing on-the ground guidance for regional planners, agencies, land-managers, conservationists, and other stakeholders.
These actions include:
Maintaining existing protected coastal habitats that are already resilient to sea level rise
Protecting resilient coastal habitats that are not yet managed for conservation
Helping some vulnerable habitats keep pace with rising water by adding sediments
Conserving and adapting some non-habitat areas to habitat as sea level rises
Adapting vulnerable human infrastructure like roads and bridges to allow habitats to move inland or natural processes to be maintained
Maintaining a healthy coast preserves the services coastal habitats provide for people such as protection from storm surges and rising seas, improved water quality, carbon storage, fisheries and recreation.
“For the first time, we have a clear picture of just how vulnerable California’s coastal habitats are to sea level rise,” said Mary Small, Deputy Executive Officer for the State Coastal Conservancy. “Californians treasure our coast, and this report highlights the urgency of implementing forward-looking strategies to protect these precious resources.”
Conserving California’s Coastal Habitat is a collaboration between The Nature Conservancy and California State Coastal Conservancy more than two years in the making. It adds to an existing body of California-specific vulnerability analyses, which are often regionally focused and/or mainly consider aspects of human vulnerability. The assessment will be used to guide future work at both The Nature Conservancy and the State Coastal Conservancy to maintain and improve upon California’s legacy of conservation investment along the coast and will provide state agencies and other stakeholders with the science foundation necessary to make the decisions today that protect the values of the coast for tomorrow.