These messy, muddy, and full of tangled roots and sea grass are doing something quietly extraordinary. They’re pulling carbon dioxide (CO₂) out of the air and tucking it deep into the earth. Into thick, heavy, coastal soils that don’t give it back. Not for a very, very long time.
They’re called blue carbon ecosystems: mangroves, seagrass meadows, tidal marshes, and they might be one of our best chances to slow down climate change.
“Ecosystems store an enormous amount of carbon, up to 30 billion tons!” said Oscar Serrano, from the Center for Advanced Studies in Blanes (CEAB-CSIC). That’s not a guess. That’s real. And it’s happening right now, while we scroll and panic and talk about “solutions.”
Carbon dioxide (CO₂) equals life
These places are wild and alive. They breathe. They shelter. They hold tiny creatures in their tangled fingers: baby fish, birds, and crabs. According to Serrano “They act as nurseries for young animals.”
But what makes them different is how they store carbon.
Unlike trees, which hold it aboveground in trunks and branches, blue carbon systems hide it below. In the muck. That slows everything down. Which means the CO₂ they absorb? It doesn’t come back up.
“Blue carbon ecosystems have a secret weapon for storing carbon longer than most terrestrial plants: they bury it in the soil and trap it there for thousands of years,” the PhD in biology added.
That’s thousands of years of safety coming from just photosynthesis, mud, and time. A huge win that deserves to be given the attention and care it deserves. And yet, we treat these places like they’re something disposable.
We’re losing them—and the carbon they’ve saved for us
More than half of these ecosystems are already gone.
And when that happens, we don’t just lose the chance to store future carbon. We release what they were keeping safe. That deep, ancient CO₂ comes rushing back into the air.
“That carbon trapped in the soil can return to the atmosphere in the form of CO₂.” It’s hard to wrap your head around the numbers. “The total amount of carbon stored in mangroves, seagrass beds, and intertidal marshes ranges from 10 to 30 billion tons,” said Oscar Serrano.
This could quietly slip away. But it is not too late; we can still stop it.
If we just protect what’s left, we could keep 300 million tons of carbon out of the air every single year. And if we bring back what we’ve lost, if we invest in restoration, we could draw down another 840 million tons.
That’s 3% of global emissions, just by letting nature do what it’s already doing. This percentage can make a big difference for climate change, especially when there are no external needs since nature does it all by itself.
We can’t save what we can’t see, but we’re learning how
Here’s a problem no one talks about: we don’t even fully know where all these ecosystems are. Some, like mangroves and salt marshes, you can spot from satellites. But others, like seagrass meadows, grow underwater. You won’t see them unless you’re looking for them. And most of the time, we’re not.
But now we have drones. We have highly advanced tech. We have artificial intelligence (AI) that can scan and map and help scientists figure out so much about these habitats. We’re finally starting to see what we’ve ignored for so long.
Because this isn’t just about blue carbon or global emissions or even climate change.
It’s about how we treat our nature, our world, and the ones that have been holding us up for so long without asking for credit. Maybe just asking to be listened to.