What are blue carbon ecosystems, and what can restoring them do for some of California's most vulnerable communities?

This article is the first in a series of six that highlight the Policy Clinic projects completed by EPM masters students in collaboration with our partners. We'd like to give a special thanks for Anthony Rogers from California Ocean Science Trust for partnering with us on this project. 

Starting with the Global Warming Solutions Act, over the past twenty years, California has committed to reducing carbon emissions and prioritizing equitable investments in the environment. Only recently have blue carbon ecosystems been recognized as natural working lands for their ecosystem services. With the inclusion of Natural and Working Lands in the state’s net zero scoping plan, the stage is being set to include blue carbon in climate mitigation policies, which will allocate more funding towards protecting both these ecosystems and the people who benefit from them. Our project falls under both of these objectives – we partnered with the California Ocean Science Trust to look at how blue carbon areas and frontline communities overlap in CA. 

Blue carbon refers to marine and coastal environments, including seagrass beds, salt marshes, and mangroves. These systems capture carbon dioxide (CO₂) from the atmosphere during photosynthesis and store it in plants and sediments. When blue carbon ecosystems are damaged or changed, they can release lots of CO₂ into the air. In fact, most blue carbon habitats store more than 2-3 times as much carbon as rainforests. However, these systems are in decline worldwide due to human activity from development, agriculture, and climate change.

These ecosystems play an invaluable role in supporting the livelihoods of nearby communities by providing various services that go beyond carbon sequestration. They serve as crucial habitats for marine species, supporting biodiversity and maintaining coastal ecosystem health. Additionally, their carbon sequestration helps mitigate the impacts of climate change, particularly on warming ocean temperatures and acidification, which threaten marine biodiversity and the livelihoods of coastal populations reliant on fish stocks. They improve water quality by trapping and filtering sediments, nutrients, and contaminants from coastal waters. They also protect coastal communities from flooding, saltwater intrusion, and extreme weather by providing natural buffers against erosion and storm surges through vegetation and dense root systems. And finally, these ecosystems also offer social benefits, including recreation, tourism, and cultural well-being, though the cultural value is difficult to define, particularly for Tribal communities. 

Through interviews and research in the current policy setting, we identified several barriers and considerations for the development of blue carbon policy and management for equity in ecological restoration-based decision-making:

• Defining Priority Communities: There are varying definitions of disadvantaged, vulnerable, frontline, or marine resource-dependent areas. Data tools such as CalEnviroscreen and the federal Climate and Economic Justice Screening Tool typically include geography, socioeconomic disparities, public health, and environmental risks (pollution). Expanding indices or using a variety of tools to incorporate racial and ethnic makeup, resource dependency, and climate change risk exposure offers a more comprehensive understanding of vulnerability.
• Data Gaps: The best available blue carbon data sources are inconsistent in temporal and spatial resolution. The data from the San Francisco Bay Area is more precise, with the region benefiting from higher research funding.
• Lack of Ecological Scope: The absence of historical information on blue carbon ecosystems makes it difficult to understand their original state, and annual fluctuations of blue carbon habitat area complicate ecosystem health assessments.
• Tribal Consultation: Indigenous input is essential for accurately understanding the cultural importance of blue carbon ecosystems, while respecting Tribal data sovereignty to manage their information and knowledge systems. 
• Research Economic Advantages: Understanding the economic benefits to frontline communities and the value of ecosystem services supports conservation efforts and benefits both coastal and inland areas.
• Community Engagement: Research and decision-making benefits from engaging with local communities, Indigenous peoples, and traditional knowledge holders. Feedback from monitoring programs and stakeholder input should refine priorities, methods, and goals for long-term success.
• Empower Community Voices: Empowering community voices and prioritizing input from those directly impacted by climate change is vital for effective restoration projects. Respect for social values and livelihoods, along with ongoing communication and collaboration, supports adaptive management.

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 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.

View the final report