The term blue carbon refers to the carbon captured and stored by the world’s ocean and coastal ecosystems. While the entire ocean absorbs CO2, scientists use “blue carbon” most specifically to describe three coastal habitats: mangrove forests, seagrass meadows, and salt marshes.
Learn more about how seagrasses and mangroves naturally help to capture carbon
Here’s the key insight that surprises most people: most of the carbon in these ecosystems isn’t in the leaves or the branches. It’s underground.
The good news: Mangroves, seagrass meadows and salt marshes capture “blue carbon” and lock it away for centuries in waterlogged soils—while also sheltering shorelines, filtering water and nurturing marine life. When we protect and restore these habitats, you get a powerful climate win that communities can feel—less erosion, more resilience, richer coastal ecosystems. The urgency is real, too: when wetlands are cleared or smothered by pollution, stored carbon can be released back into the atmosphere. This feature unpacks how blue carbon works, what’s threatening it, and the practical actions already making a difference—from conservation to smart restoration—alongside the rapid emissions cuts needed to keep these natural defenders thriving. The National Oceanic and Atmospheric Administration (NOAA) describes these systems as among the most carbon-dense ecosystems on earth — and the science behind that claim is striking.
Read the full article: Climate Action: Blue Carbon is a Powerful Climate Defence, published 6th April 2026 by Samantha Burchard EARTHDAY.ORG
