While occupying only less than 2% of the world’s ocean area, coastal ecosystems like mangroves, seagrass beds and marshes hold immense potential in addressing climate change, protecting biodiversity and providing critical ecosystem services to populations living within and beyond these areas. However, these ecosystems are being degraded at a concerning rate and there is an urgent need to increase efforts in conserving and restoring blue carbon ecosystems.
What is blue carbon?
Blue carbon refers to the carbon stocks sequestered in coastal wetland ecosystems. Plant species in these environments grow rapidly, allowing them to absorb carbon dioxide (CO2) from the atmosphere at a fast pace. Anaerobic soils slow the decomposition of plant matter (which releases CO2 in the process), and this forms deep, carbon rich soils. These unique ecological conditions allow them to store up to five times the amount of carbon per unity area compared to tropical forests. (Source: National Ocean Service)
Why blue carbon ecosystems matter?
Beyond providing efficient carbon sequestration, blue carbon ecosystems offer myriad other ecosystem services. They provide habitats for a wide variety species, which not only maintain the ecosystem health but also support fisheries and local diets. Mangrove forests help reduce wave energy, shielding the coast from the impacts of storms. With the increase in frequency and intensity of storms due to climate change, blue carbon ecosystems offer a nature-based solution for adapting to these impacts. Coastal ecosystems also improve water quality for local communities by keeping salt water from infiltrating freshwater resources.
The threats we face
Despite their value and importance, blue carbon ecosystems continue to face degradation by human activities such land reclamation, coastal development, pollution or conversion of land for agriculture and aquaculture. Additionally, changes in the abiotic conditions due to climate change, such as water temperature, weather and sea level rise are also growing stressors on these ecosystems. Studies estimate that seagrass beds are declining at around 7% annually and the International Union for Conservation of Nature’s (IUCN) 2024 assessment revealed that more than half of the world’s remaining mangroves are at risk of collapse by 2050. These alarming numbers underscore the urgent need to prioritise and scale protection and expansion of blue carbon ecosystems.
The role of carbon credits
Carbon credits generated through the voluntary carbon market (VCM) have the potential to efficiently mobilise funding to support blue carbon mitigation projects. However, blue carbon is relatively nascent in the VCM, comprising only 0.2% of issuances. Blue carbon credits generally command price premiums compared to their green carbon counterparts – the average price traded for blue carbon credits ranges from USD 13 to USD 35, compared to USD 8 and USD 10 for REDD+ credits. These higher prices can be attributed to low project availability but high demand interest, high implementation costs, and the significant co-benefits for biodiversity and local communities.
Challenges and opportunities ahead
With the growing awareness and demand for blue carbon credits, there is large potential to scale blue carbon solutions. However, several obstacles remain before this can be achieved. Robust methodologies for blue carbon projects are still in development and the lack of data on specific projects makes it difficult to establish baselines or monitor progress. Difficulties may also arise in securing land tenure and carbon rights in blue carbon ecosystems which are often situated on communal lands.
Carbon credits are vital for overcoming barriers to scaling blue carbon. Income from the VCM can support blue carbon project development and investment in better monitoring systems. Current willingness to pay a premium for blue carbon credits is a promising sign of demand.
With more blue carbon projects in the VCM, this will boost conservation and restoration of important ecosystems which will enhance our response to climate change.
