Rising Tides of Resilience

Prepared for the  California Ocean Science Trust  by UC Davis Graduate Program of  Environmental Policy and Management  students: Alex Berk, Desmond Colley, Hannah Mone, Annika Ragsdale, and Sarah Rosenthal

 _{Title Image provided by Phillip Colla,  OceanLight .} 

Carbon sequestration refers to the removal and storage of carbon dioxide (CO ₂ ) from the atmosphere. Different types of carbon storage, categorized as green, blue, and brown carbon, are each associated with specific ecosystems. Green carbon is linked to terrestrial ecosystems such as forests and grasslands, where carbon is stored in the biomass of plants and trees as well as in the soil. Blue carbon pertains to marine and coastal environments, including mangroves, seagrass beds, and salt marshes, where carbon is captured and stored primarily in plants and sediments. Brown carbon is found in soils, peatlands, and permafrost, where organic matter accumulates and stores carbon over long periods. Each type of carbon storage plays a unique role in reducing atmospheric carbon dioxide levels, and recognizing these roles enables better management and conservation efforts to enhance their carbon sequestration capacities.

Blue carbon ecosystems are natural environments in the ocean and along coastlines that capture and store carbon dioxide from the atmosphere. Blue carbon ecosystems capture CO ₂  from the atmosphere during photosynthesis and convert it into organic carbon. This carbon is stored in vegetation and underlying sediments for long periods, from decades to millennia. Blue carbon systems can store much more carbon per unit than land networks and are part of the ocean, which as a greater system is responsible for storing 90% of the world’s carbon. In spite of this carbon sequestration potential, blue carbon systems are degraded or destroyed at four times the rate of tropical forests. Global climate change threatens to exacerbate this loss.

The three types of blue carbon ecosystems include: seagrass meadows, salt marshes, and mangrove forests.

Seagrass Meadows:

These are underwater grass-like plants found in shallow parts of the ocean. They form large, green meadows on the ocean floor. Seagrass meadows, found along the coasts of all continents except Antarctica, are incredibly important for the environment. They are much better at capturing and storing carbon dioxide than tropical rainforests—up to 40 times more effective per unit area.

Despite covering less than 0.2% of the world's oceans, seagrass meadows hold about 10% of the carbon buried in ocean sediment each year. Besides storing carbon, seagrass meadows filter out sediment and nutrients from the water, which protects coastlines from erosion, storms, and flooding. They also provide important habitats for many marine animals, including fish, sea turtles, and the California spiny lobster.

Unfortunately, seagrass meadows are one of the world's most threatened ecosystems, with around 1.5% being lost each year due to activities like deforestation and dredging. Globally, about 29% of seagrass habitats have already been lost, making their conservation critical for both climate and marine life. In California, eelgrass meadows can be found along the entire coastline.

Salt Marshes:

Tidal salt marshes are coastal wetlands regularly flooded with seawater, and can be characterized by grasses, shrubs, and trees. The deep soils of tidal marshes, made from mineral sediment and organic material, store most of the carbon in these ecosystems. Tidal marshes can sequester carbon at rates two to four times higher than mature tropical forests. Besides storing carbon, they filter pollutants from land runoff, improve water quality, and provide vital habitats for many marine species, and support healthy fisheries and marine life.

Tidal marshes also help protect coastal communities by absorbing the energy from storms and floods and preventing erosion. However, these important ecosystems are disappearing at a rate of 1-2% each year due to human influence from coastal development, agriculture, and rising sea levels. Protecting tidal marshes is essential for maintaining their environmental and protective benefits.

Mangrove Forests:

Mangroves are tropical forests, with unique roots, that grow in tidal waters. They excel at storing carbon, offering immense potential in combating climate change. They serve as habitats for various animals, support fisheries, filter pollutants, and provide protection from storms and erosion, offering billions of dollars' worth of ecosystem services annually. Despite their importance, mangroves have been dwindling due to deforestation for aquaculture and coastal development, with global losses reaching 30-50% over the past 50 years. Despite covering only 0.7% of tropical forest areas, 10% of global emissions from deforestation are a result of mangrove loss. Protecting mangroves is essential for their ability to store carbon, support biodiversity, protect coastlines, and provide livelihoods for local communities. There are no mangroves in California because mangroves are only found in the tropics.

What About Kelp?

Mapping kelp is challenging due to its transience and varying health from year to year. Kelps and other macroalgae are known to sequester carbon but their exact amounts and locations are difficult to confirm. Kelp was ultimately omitted from this project for simplicity and because it is not currently considered blue carbon by California, but researchers and practitioners recognize the need to improve understanding for habitats with high sequestration potential.

Understanding these distinctions is essential for evaluating how various ecosystems contribute to carbon sequestration and for developing effective strategies to mitigate climate change. Blue carbon ecosystem preservation faces challenges like urban development, pollution, climate change effects, invasive species, unsustainable fishing, lack of awareness, resource scarcity, and governance issues. Addressing these requires public education, robust laws, sustainable planning, pollution management, and cooperation among governments, communities, non-governmental organizations (NGOs), and international organizations.

Blue carbon ecosystems provide invaluable benefits beyond carbon sequestration to surrounding communities in the form of regulating, provisioning, and cultural services. These additional services are often called "co-benefits," which include:

• Climate regulation
• Habitats for wildlife, including economically important fish species
• Water quality improvements
• Protection against sea level rise and storm surges
• Recreation/tourism
• Cultural benefits

Blue carbon ecosystems play a crucial role in supporting biodiversity and maintaining the health of coastal ecosystems. They act as nurseries and habitats for various marine species, including fish, mollusks, and crustaceans. The climate regulating effects of carbon sequestration counteract warming ocean temperatures and ocean acidification, which threaten marine biodiversity, including the fish stocks upon which many coastal populations rely for sustenance and livelihoods.

Blue carbon systems help mitigate pollution by trapping and filtering sediments, nutrients, and contaminants from coastal waters, thus improving water quality. Rising sea levels increase the vulnerability of coastal communities to flooding and saltwater intrusion into freshwater sources, and extreme weather events pose a greater risk as they become more frequent and severe. The root systems of coastal vegetation provide natural barriers against erosion, storm surges, and sea-level rise. Without coastal vegetation, communities are more exposed to the destructive impacts of extreme weather events and sea-level rise.

Living in proximity to these ecosystems also offers social services including recreation, tourism, and culture/wellbeing. The value of cultural benefits is difficult to define, and for tribal communities proves especially challenging. Cultural Tribal information is publicly inaccessible, primarily because historic marginalization and systemic discrimination have led to sentiments of mistrust. As the state works to rebuild Tribal relationships, respecting these sovereign nations means recognizing that cultural knowledge may be sensitive information.

The impacts of global climate change are already being felt worldwide, and coastal communities are particularly vulnerable. More than half of the world's population resides within 200km of a coast, making these ecosystems and their co-benefits vital for livelihoods , food security, and overall well-being. Preserving and restoring these blue carbon ecosystems is essential not only for mitigating climate change but also for ensuring the resilience of coastal communities and the multitude of services they depend on.

The Greenlining Institute’s  Environmental Equity guidebook  provides the following definition of frontline communities, later used by the Ocean Protection Council and Ocean Science Trust: “lower-income communities, communities of color, Indigenous peoples and tribal nations, and immigrant communities who are especially vulnerable to the impacts of climate change because of decades-long, pervasive socioeconomic conditions that are perpetuated by systems of inequitable power and resource distribution.”

The state lacks a specific definition for frontline communities, instead relying on the term "disadvantaged communities," overseen by CalEPA. Senate Bill (SB) 535 assigned CalEPA to establish standards considering factors like geography, socioeconomic status, public health, and environmental risks (pollution.) SB 535 also extends inclusion to federally recognized tribes.

However, the definition of disadvantaged communities varies among state agencies, with some primarily focusing on median household income or a mix of other indicators. This variance adds complexity to identifying which communities qualify as disadvantaged. In 2021, the federal government introduced Justice40, aiming to allocate 40% of federal funding from climate, clean energy, and housing programs to historically marginalized communities. For our project, we used both the SB 535 Disadvantaged Communities mapping tool (also known as CalEnviroScreen,) and Justice40 maps to pinpoint frontline communities in California. We chose these tools because they determine state and federal allocation of climate funding.

Community-based organizations (CBOs) play a significant role in fostering public awareness and engagement in blue carbon ecosystem restoration efforts, while also advocating for affected communities. For this study, we conducted interviews with various CBOs in San Francisco Bay, San Diego Bay, and Humboldt/Arcata Bay to gain insights into their experiences with restoration projects. One such organization,  Wildcoast , is actively involved in the restoration and preservation of San Diego Bay. Meanwhile, The Watershed Project, operating in San Francisco Bay, is currently navigating the permitting process for the  North Richmond Shoreline Adaptation Project  as of May 2024. This collaborative endeavor aims to address multiple needs, including flood protection, habitat restoration, and providing safe public access for a frontline community in North Richmond.

The Global Warming Solutions Act of 2006 (AB32) introduced the  Scoping Plan , which set goals for the state to reduce emissions to 1990 levels by 2020, 48% below 1990 levels by 2030, and 85% below 1990 levels by 2045 to achieve carbon neutrality.

Assembly Bill1757 ( AB1757 ) was signed into law in 2022 to compliment AB32 and to establish the Natural and Working Lands Climate Smart Strategy. This required that natural carbon sequestration and nature-based solutions be incorporated into carbon neutrality targets set for 2030, 2038, and 2045. AB1757 also established the types of Natural and Working Lands considered for state recognized nature-based solutions: forests, shrublands/chaparral, grasslands, croplands, developed lands, delta wetlands, and sparsely vegetated lands. Even though wetlands are recognized for their carbon sequestration benefits, blue carbon ecosystems are currently excluded in the 2022 Scoping Plan, meaning they have yet to be integrated into the state's official carbon neutrality strategy.

Executive Order (EO) N-82-20, also known as  30x30 , was signed by Governor Newsom in 2020, and establishes a state goal to conserve 30% of California's lands and coastal waters by 2030. The 30x30 goal has three main objectives: protect and restore biodiversity, mitigate and adapt to climate change, and expand access to the outdoors. This EO is implemented through the  Natural and Working Lands Climate Smart Strategy  and recognizes the co-benefits of protecting blue carbon ecosystems.

The National Oceanic and Atmospheric Administration (NOAA) published its  California Eelgrass Mitigation Policy  (CEMP) and Implementing Guidelines document in 2014, which states the policy goal of California having no net loss of eelgrass habitat: any lost eelgrass must be replanted at a ratio of 1.2 to 1. If a project is going to damage eelgrass, NOAA may recommend a survey of existing eelgrass to identify the effects of development projects on current habitats. NOAA may then recommend mitigation measures depending on the level of impact.

Assembly Bill 52 ( AB 52 ), which went into effect in 2015, required that the Office of Planning and Research update the California Environmental Quality Act (CEQA) Guidelines to include assessment of tribal cultural resources in the environmental review process. These tribal cultural resources could be a site, feature, place, landscape, or sacred object that is of cultural value to a California Native American Tribe. By making this amendment, public agencies are required to consult with Tribes during the CEQA process. They may also be required to mitigate impacts to cultural resources, such as through avoiding restoration activities in certain sites or protecting the resources found in project areas.

Humboldt County in Northern California was chosen as a case study site due to the high discrepancy between disadvantaged community mapping tools SB 535 and Justice40. In Figure 2, the left map indicates that few communities are designated as disadvantaged by SB 535 indicators. The map on the right however shows that a large area of Humboldt and Arcata Bay are considered disadvantaged. This variation may affect the amount of funding allocated to these communities through state and federal programs.

This discrepancy in disadantaged community area highlights the importance of expanding the definition of a disadvantaged community by the state which is further discussed in the Takeaways & Recommendations section.

San Diego was selected as another case study location because it features a concentration of blue carbon ecosystem and disadvantaged community overlap. San Diego Bay also contains approximately 15% of seagrass habitats within California. The Tijuana Estuary to the south of the bay is the largest tidal wetland in Southern California.

Our discussions with community-based organizations in the San Diego area have shed light on the challenges faced by local communities in accessing the coast, primarily due to the prevalence of industries and ports. However, despite these obstacles, blue carbon continues to offer valuable co-benefits such as storm surge mitigation, wildlife habitat preservation, and enhancement of water quality. Figure 3 indicates that several areas in San Diego experience impaired water quality as a result of urban and industrial runoff, as well as the nearby draining of the Tijuana River. The restoration/conservation of blue carbon ecosystems in the San Diego area would therefore be beneficial for improving water quality.

Our final case study focuses on the San Francisco Bay Area due to its significant overlap between blue carbon ecosystems and disadvantaged communities, as well as the fact that 87% of California's tidal wetlands are located in the San Francisco Estuary. Figure 4 shows the overlap in darker orange where disadvantaged communities are within a 0.5 mile radius of these blue carbon ecosystems. Several disadvantaged communities adjacent to blue carbon ecosystems of potential interest for restoration/conservation funding include but are not limited to: Richmond, Vallejo, Oakland, and San Jose.

Due to low elevations of communities around the San Francisco Bay and the proximity of infrastructure to the coast, large portions are projected to experience inundation by the end of the century. Various models have been generated to determine what amount of sea level rise is to be expected under different carbon emissions cutting scenarios. In Figure 5, the overlap of San Francisco Bay Conservation and Development Commission  (BCDC) sea level rise data  and SB 535 indicates that substantial portions of disadvantaged communities will be underwater.

Sea level is projected to rise 24 inches for the intermediate-low scenario and 66 inches for the intermediate-high scenario by 2100, depending on the extent of carbon emissions cutting. Both of these emissions scenarios are from the  2024 California Sea Level Rise Guidance. 

By trapping and accumulating sediments over time, blue carbon ecosystems effectively raise the elevation of the land they inhabit, helping to counteract the effects of rising sea levels. In addition, their dense vegetation acts as a barrier, dissipating wave energy and reducing the force of storm surges, thus protecting coastal areas from erosion and damage during extreme weather events. This inherent resilience enhances the stability and longevity of coastlines, making blue carbon ecosystems indispensable components of coastal management and adaptation strategies in the face of climate change-induced sea level rise.

Improve the resolution of blue carbon geospatial data, incorporating historical extents and ecosystem health indicators to enhance the effectiveness of restoration efforts through:

1. High-Resolution Remote Sensing: to allow for more accurate mapping and monitoring of blue carbon ecosystems at finer scales.
2. Historical Extent Analysis: Incorporate historical datasets for insights into ecosystem dynamics and informing restoration priorities.
3. Ecosystem Health Indicators: Develop ecosystem health indicators to assess the condition and resilience of ecosystems to monitor changes in ecosystem health and tailor restoration to address specific ecological challenges and vulnerabilities.
4. Community Engagement and Local Knowledge: Involve local communities, indigenous peoples, and traditional knowledge holders in the collection, interpretation, and validation of blue carbon geospatial data.
5. Iterative Monitoring and Adaptive Management: Use feedback from monitoring programs and input from stakeholders to improve priorities, methods, and goals and ensure long-term success.

By improving the resolution of blue carbon geospatial data and integrating historical extents and ecosystem health indicators, restoration efforts can be better informed, targeted, and adaptive, leading to more effective conservation and restoration of blue carbon ecosystems and the valuable ecosystem services they provide.

Investing in kelp research, particularly focusing on mapping kelp locations and loss using remote sensing techniques, as well as understanding the dynamics of carbon flux within kelp ecosystems can provide valuable insights into their role in mitigating climate change and their potential as carbon sinks. Identifying areas of high biodiversity and vulnerability informs conservation and management efforts.

Current SB 535 metrics include geography, socioeconomic disparities, public health, and environmental risks (pollution.) Exploring other indices for evaluating frontline communities based on metrics not available in CalEnviroScreen, including race, resource dependency, and climate change risk exposure broadens the inclusion of those predisposed to experience disproportionate impacts, providing a more comprehensive understanding of vulnerability.

The disparities and unique challenges faced by non-federally recognized Tribes can often go unaddressed in broader environmental justice efforts. Conducting a comparison of Tribal lands identified as SB 535 disadvantaged communities in CalEnviroScreen with all Tribal lands in the State of California could identify areas where non-federally recognized Tribes may be missing.

Conducting interviews and gathering personal narratives not only tracks linkages of how and where the co-benefits extends and sheds light on the direct benefits of blue carbon ecosystems to frontline communities, but can also empower these communities to become active participants in conservation efforts and decision-making processes. This participatory approach can foster a sense of ownership, pride, and resilience within the communities, leading to more sustainable and equitable outcomes for both people and the planet.

The economic advantages associated with proximity to blue carbon ecosystems extend beyond coastal areas and have broader implications for ecosystem restoration and sustainable development. Research regarding investing in the conservation and restoration of these ecosystems not only supports coastal communities but also contributes to the resilience and prosperity of inland regions through the provision of ecosystem services, climate regulation, and economic opportunities.

When it comes to implementing restoration projects aimed at improving blue carbon ecosystems in disadvantaged communities, there are opportunities to make the regulatory and permitting processes more efficient. This means making it easier and quicker for these communities to obtain the necessary permissions and approvals for their restoration initiatives. By streamlining these processes, the aim is to reduce the amount of time and money spent on navigating bureaucratic hurdles, enabling these communities to carry out their restoration projects more swiftly and affordably.

Actively engaging with local communities throughout the planning, implementation, and evaluation stages of restoration projects ensures that communities have a more meaningful role in shaping project goals, strategies, and outcomes. Incorporating the unique knowledge and expertise that local communities possess about their environments respects cultural values and traditions into restoration efforts. Ongoing communication and collaboration with communities beyond the duration of restoration projects supports the sustainability of restoration projects and the continued resilience of ecosystems. Empowering community voices and prioritizing the input and perspectives of those directly impacted by climate change in the decision-making process is a crucial part of adaptive management for the success and effectiveness of restoration projects.

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