Coastal ecosystems, such as mangroves, seagrass meadows, and salt marshes, play a vital role in supporting the well-being of coastal communities. These ecosystems provide critical services, from sustaining local diets and fishing industries to protecting homes and infrastructure from erosion and storm damage. However, the benefits of these “blue carbon ecosystems” extend far beyond coastal regions. They offer a powerful ally in addressing global challenges such as climate change, biodiversity loss, and sustainable development.
What Is "Blue Carbon"?
Blue carbon refers to carbon that is captured from the atmosphere and stored in marine and coastal ecosystems like seagrass meadows, mangroves, and tidal marshes. These unique ecosystems are carbon removal powerhouses, capable of storing up to five times more carbon per area than tropical forests, and absorbing carbon from the atmosphere about three times as quickly. Remarkably, despite covering only approximately 0.5% of the seafloor, blue carbon ecosystems may account for more than 50% of all carbon buried in marine sediments.
The efficiency of blue carbon ecosystems in removing and storing carbon is due to the rapid growth of plant species they contain. These plants absorb carbon dioxide from the atmosphere at a fast pace. Moreover, they thrive in oxygen-deprived or “anaerobic” soils, which slows down the decomposition of plant matter, allowing carbon to be sequestered for extended periods—often hundreds or thousands of years.
What Are The Benefits?
Preserving Biodiversity: Blue carbon ecosystems serve as valuable hubs for biodiversity, providing habitats for a wide variety of marine and coastal species. They are critical to maintaining ecosystem health and supporting local diets and fishing industries.
Protecting Coastlines: In tropical areas globally, mangrove forests act as a natural defense against coastal storms by absorbing some of the storm’s energy, thus reducing damage from extreme weather events like cyclones. Additionally, blue carbon ecosystems help reduce coastal erosion, stabilising coastlines and protecting homes and infrastructure.
- Improving Food and Water Security: Blue carbon ecosystems contribute to water quality and food security by preventing saltwater intrusion into freshwater resources. They also serve as nursery grounds for a diverse array of marine and coastal life, supporting artisanal fisheries and bolstering local economies.
Sustaining Coastal Economies: Beyond local fishing, these ecosystems offer recreational and ecotourism opportunities, creating jobs and boosting related industries like food and hospitality. For instance, in the Florida Keys National Marine Sanctuary, ecotourism associated with mangroves and seagrass contributes significantly to the state’s economy.
Why Are They At Risk?
Despite their immense value, blue carbon ecosystems are facing rapid degradation and loss. Globally, approximately 50% of salt marshes, 35% of mangroves, and 29% of seagrass meadows have been degraded or lost since the mid-twentieth century. These ecosystems are caught in a “coastal squeeze” due to climate-driven impacts like sea-level rise and extreme weather events, as well as the development of coastal areas.
Climate change has intensified hurricanes and storms, causing damage to natural structures and reducing the area available for blue carbon ecosystems to thrive. Moreover, urban development and commercial activities, such as aquaculture and agriculture, have led to the destruction of these ecosystems. These practices not only harm blue carbon ecosystems but can also result in the release of stored carbon into the atmosphere.
Protecting and Harnessing Blue Carbon Ecosystems
Restoring and Managing Projects: There is a growing momentum behind projects aimed at restoring, protecting, or sustainably managing blue carbon ecosystems. These initiatives offer the opportunity to monetize the value of stored carbon through carbon credits, which can fund further conservation efforts while benefiting local communities
Adopting Best Practices: Governments and project developers must follow international best practices for blue carbon projects to ensure equitable and lasting results. Proper carbon baselines, involvement of local communities, and consideration of social and ecological factors are vital for success.
- Safeguarding Local and Indigenous Rights: Inclusive involvement of all stakeholders, including local communities and Indigenous groups, is essential for the success and sustainability of blue carbon initiatives. Upholding their rights and preserving natural ecosystems are crucial for long-term effectiveness.
Expanding Blue Carbon Finance Pathways: Investors and stakeholders should explore a diverse range of project options and non-market financing approaches to support conservation and restoration efforts.
Blue carbon ecosystems offer a natural and effective solution to combat climate change, protect biodiversity, and ensure sustainable development. By investing in these ecosystems and supporting local communities, we can harness their vast potential and address global crises effectively. Preserving blue carbon ecosystems is not only essential for coastal communities but for the well-being of our entire planet. Through thoughtful management and equitable partnerships, blue carbon initiatives can truly become a driving force for positive change on a global scale.