Climate policy: The benefits of blue carbon sequestration

Coastal habitats, such as kelp forests, can absorb carbon from the atmosphere and store it in their vegetation and soil - a process known as sequestration. “Blue carbon” potential is the calculated capacity of coastal vegetation to store carbon. Kelp forests and salt marshes sequester carbon at nearly double the rate of terrestrial forest ecosystems. However, coastal habitats are vulnerable to losses from land-use change and sea level rise. Including coastal habitats in climate change policies, such as the Paris Agreement, can help to maintain these ecosystems while also conserving large amounts of carbon removal potential.  

A better understanding of the true value of coastal habitat’s sequestration potential can support the integration of coastal habitat conservation and climate change policies. A recent research article by L.M Wedding et al. in Science Direct calculates the monetary value of blue carbon potential across California. The study found that one hectare of a coastal vegetated region can provide natural services valued between $7,000 to $44,000. These ecosystems provide a sustainable and natural way to remove carbon from the atmosphere. Thus, incorporating the benefits of blue carbon into climate policy is a good model for future approaches. For example, the use of a country’s natural assets, such as coastal ecosystems, can be included in the measurement of their greenhouse gas emissions. This research demonstrates that protecting coastal ecosystems, such as mangroves and saltmarshes, can help countries meet their commitments to the Paris Agreement.  

The conservation and restoration of blue carbon ecosystems provides a nature-based solution that can not only help us tackle the climate crisis, but enhance biodiversity and contribute to sustainable development. Despite the potential blue carbon ecosystems have for aligning with the ethos of the U.N. Sustainable Development Goals, blue carbon ecosystems are increasingly threatened by direct and indirect human causes, ranging from climate change to deforestation. As climate policy increasingly focuses on greenhouse gas removal, there is a growing need to map and quantify the value of marine and coastal ecosystems, so that we can better understand the consequences of their continued loss and damage and advocate for their protection.  

The United Sates is currently the world’s second largest emitter of greenhouse gases and the world’s largest historical emitter. Accordingly, it has a major role to play in helping the world meet the 1.5°C temperature target established by the Paris Agreement. Blue carbon can help the United States do that - only the country has no comprehensive legal framework that mandates the protection of coastal ecosystems and their blue carbon potentials. California, however, has a potentially perfect opportunity to promote the implementation of blue carbon climate policies: its statewide climate adaptation plan. California’s adaptation plan, and its large area of coastal blue carbon ecosystems, provides a clear opportunity to implement blue carbon sequestration strategies across various state agencies in support of reducing greenhouse gas emissions.  

Incorporating blue carbon into U.S. subnational climate change policy will help ensure the success of California’s statewide adaption plan. The United States can also work towards the ambitious goals set in the Paris Agreement by leveraging the blue carbon sequestration potential in California. In turn, including coastal habitats in climate change policies, such as the Paris Agreement, can help to maintain these ecosystems while also conserving large amounts of carbon removal potential.