California Can Leverage ‘Blue Carbon’ to Help Achieve Climate Goals

New study details why and how to include coastal wetlands in state greenhouse gas-reduction planning

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California Can Leverage ‘Blue Carbon’ to Help Achieve Climate Goals
Salt marshes
New research shows that, if conserved and restored, California’s tidal wetlands—such as these salt marshes, part of the Hayward Regional Shoreline in the San Francisco Bay—and eelgrasses would contribute meaningfully to the state’s climate goals.
Keith Cuddeback Flickr

California can measurably enhance the capture of climate-warming carbon dioxide by expanding efforts to conserve and restore the state’s tidal wetlands and eelgrasses, according to a new report conducted by the San Francisco Estuary Institute with support from The Pew Charitable Trusts. Tidal marsh and seagrass ecosystems, which cover approximately 57,000 acres throughout the Golden State, are known as “blue carbon” habitats because of their ability to efficiently capture and store carbon at rates comparable to, or even greater than, those of forests.

In addition to absorbing greenhouse gases, California’s tidal wetlands and eelgrasses provide significant benefits to people and nature, including nurturing commercially and recreationally important fish and shellfish, improving water quality, and helping to protect coastal communities from flooding. The report concludes that restoring 21,000 acres of San Francisco Bay tidal wetlands and eelgrasses could remove 27,000 additional metric tons of carbon dioxide equivalent—roughly the emissions from 6,000 cars—from the atmosphere and surrounding waters each year. By setting this and other ambitious coastal habitat restoration targets in the state’s 2022 Climate Change Scoping Plan and future major climate initiatives—and then achieving those goals—California could harness the power of its blue carbon ecosystems in service of the state’s overall greenhouse gas-reduction commitments.

The study, which was conducted to inform the state’s climate managers, also highlights how additional funding for recurring mapping of coastal habitats, more data collection in regions other than the San Francisco Bay, and expanded statewide coordination of efforts to quantify the effects of wetland restoration could yield more precise and far-reaching measurement of blue carbon in the state.

The Pew Charitable Trusts provided funding for this project, but Pew is not responsible for errors in this paper and does not necessarily endorse its findings or conclusions.

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