In the race to stop emissions that cause global warming, environmentalists draw attention to a little-remembered ally: "blue carbon". On World Oceans Day, celebrated this Monday (8), experts highlight the role of coastal ecosystems in combating climate change. The concept of blue carbon refers to carbon dioxide (CO₂) captured and stored by marine environments such as mangroves, salt marshes, and prairies. These environments function as sinks for carbon dioxide, removing it from the atmosphere, reducing the impacts of global warming. Related news: Campaign calls for the creation of a reserve to protect mangroves in Pernambuco. The north coast of Rio de Janeiro has 25% of the coastal zone in an unstable situation. Improper constructions worsen the problem of coastal erosion in Brazil. “The ocean absorbs around 30% of global CO₂ emissions and produces more than half of the oxygen we breathe, according to data from SOS Oceano”, says Natali Piccolo, director of the Marine Coastal Program at Conservation International (CI-Brazil). "The Amazon is commonly called the 'lungs of the world', but the ocean fulfills the equivalent of this role. This does not, of course, rule out the importance of the tropical forest in regulating the climate", he adds. Additionally, these coastal vegetations provide shelter for biodiversity, support artisanal fisheries, and help protect coastal communities against erosion, storm surges, and extreme weather events.    Mangrove in Paranaguá Bay, area of ​​the Great Atlantic Forest Reserve, where monitoring is carried out by researchers from the Marine Biodiversity Recovery Program (Rebimar). Photo: Fernando Frazão/Agência Brasil Brazilian coast Brazil is home to the largest continuous system of mangroves in the world, on the Amazon coast, a condition that puts the country in a strategic position to lead nature-based solutions aimed at tackling the climate crisis. However, for WWF-Brazil conservation analyst Marina Corrêa, the ocean receives less attention than other Brazilian biomes. "The sea is still, in many ways, the invisible system of Brazilian conservation. Historically, the ocean has been treated as an empty blue immensity, when in fact it is a living territory, full of biodiversity, culture, work and ways of life", says the analyst. She recalls that the Brazilian Marine-Coastal System occupies around 5.7 million square kilometers, equivalent to approximately 40% of the national territory, and that more than half of the population lives in this ecosystem. Still, the Amazon, Cerrado and Atlantic Forest concentrate most of the public, political and financial attention focused on conservation. Traditional people  The growth of interest in blue carbon projects has also raised discussions about territorial rights and the participation of traditional communities. For the WWF-Brazil analyst, lasting results depend on respect for territorial rights and fair sharing of the benefits generated. “The success of these initiatives should not only be measured by the amount of carbon stored, but also by the ability to strengthen territories, conserve biodiversity and improve the quality of life of the people who historically take care of these ecosystems”, says Marina Corrêa. When degraded, these environments no longer offer essential services, such as the maintenance of fishing stocks, the natural protection of the coast and the conservation of biodiversity. The destruction of these ecosystems can also release carbon accumulated over decades or centuries into the atmosphere, worsening global warming.   Herons in the Ajuruteua mangrove forest, close to Vila dos Pescadores, in the area of ​​the Caeté-Taperaçu Marine Extractive Reserve. Photo: Fernando Frazão/Agência Brasil Beyond carbon For environmental organizations, protecting the oceans also means protecting jobs, food security, traditional cultures and forms of subsistence built over generations. “Globally, the largest income in the ocean is generated by fishing, which supports 100 million jobs and produces 80 million tons of marine fish, in addition to 30 million tons from marine aquaculture, which supports the food security of thousands of people, by providing high-quality protein”, says Natali Piccolo. In Brazil, around 1.7 million artisanal fishermen directly depend on the health of marine ecosystems, according to the General Register of Fishing Activity, from the Ministry of Fisheries and Aquaculture. In this sense, the joint work of public institutions with civil society organizations is essential to guarantee a more promising future for the oceans. “Our action is systemic, to fill the gaps in the protection, management and restoration of marine ecosystems (mangroves, coral reefs, restingas), while helping the people of the sea to prosper, as well as Brazilian society to develop knowledge and experience of the ocean”, says Natali Piccolo, from CI-Brasil. Marina Corrêa, from WWF Brazil, explains that the organization's strategy for the coming years is organized into four main fronts: strengthening marine protected areas, conservation and restoration of coral reefs (the ecosystem most vulnerable to climate change), promoting a fair energy transition and political advocacy to strengthen ocean governance in Brazil and internationally.