Carbon sequestration in the oceans, also known as blue carbon, plays a crucial role in the fight against climate change. By capturing and storing carbon dioxide, marine and coastal ecosystems such as mangroves, salt marshes, and seagrasses act as natural carbon sinks. This article explores the various aspects of blue carbon, from its definition to its stakes, including the challenges and opportunities it presents.
What is blue carbon?
The term blue carbon refers to carbon dioxide removed from the atmosphere by coastal and oceanic ecosystems. This carbon is then stored in the form of biomass and sediments, primarily through mangroves, salt marshes, and seagrasses. These ecosystems are remarkably effective at sequestering carbon, making this storage method particularly interesting for mitigating the effects of climate change.
Blue carbon ecosystems
The main ecosystems of blue carbon include mangroves, salt marshes, and seagrasses. These areas are capable of capturing and storing large amounts of carbon, often over extended periods ranging from hundreds to thousands of years. For instance, mangroves, which grow in tropical and subtropical regions, have complex root systems that trap carbon-rich sediments.
The essential role of blue carbon
Blue carbon plays a vital role in climate regulation by limiting the amount of carbon dioxide in the atmosphere. By storing this carbon, marine and coastal ecosystems help reduce the greenhouse effect and slow down global warming. Moreover, these ecosystems contribute to the protection of biodiversity and the provision of essential ecological services, such as protecting coastlines from erosion and storms.
The challenges of blue carbon sequestration
Although blue carbon sequestration has many advantages, it also faces several challenges. The climate profitability of these ecosystems remains debatable. Indeed, the methods of calculating and monitoring carbon sequestration may vary, making it difficult to accurately estimate their contribution to combating climate change. Furthermore, these ecosystems are often threatened by human activities such as urbanization, pollution, and climate change itself.
Opportunities and initiatives around blue carbon
Numerous initiatives are underway to maximize the potential of blue carbon. For example, France, which has the second largest maritime domain in the world, has considerable potential for blue carbon sequestration. Actions are also being taken at an international level, with conferences and webinars dedicated to defining, addressing, and exploring the opportunities of blue carbon. These efforts aim to maximize the protection and restoration of marine and coastal ecosystems to effectively combat climate change.
