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Blue carbon: All the reasons why we love it, and so should you

Zoë Sanders

Coastal and marine ecosystems lock away massive amounts of blue carbon but have long been overlooked as a climate solution. Can we give blue carbon the attention it deserves?

Image © Curioso Photography

Zoë Sanders

Image © Curioso Photography

The carbon story

As a building block of all living things, carbon is everywhere. Carbon atoms are in our food, our clothes, our air, and our DNA — nearly 20% of the human body is made up of carbon, second only to oxygen. But in the rush to capitalize on natural resources to fuel modern lifestyles, underpinned by the dysfunctional practices of racial injustice and extractivism, carbon has gained a toxic reputation as pollution from fossil fuel emissions spirals out of control, heating up the planet and threatening our communities.

The silver lining in all this? Powerful nature-based solutions to climate change already exist, with the ocean poised to be at the heart of the new carbon story we all need, one of hope and resilience, rather than despair and destruction.

Jeremy Bishop

The color blue

Did you know that scientists use a rainbow color spectrum to describe different types of carbon and their locations? Green carbon is stored in inland forests, while you’ll find the unusually named teal carbon in freshwater wetlands like swamps, marshes, and bogs. There are also black, brown, and red carbon classifications.

But given that we’re a community of ocean lovers who are determined to help save our seas and tackle climate change, it will come as no surprise that it’s blue carbon that most fascinates and inspires us.

A mangrove tree in Walakiri Beach, East Sumba Regency, Indonesia · Sutirta Budiman

The power of blue carbon

Blue carbon is situated in coastal and marine environments in 151 countries, with Australia, Cuba, and Indonesia topping the list for contributing the most blue-carbon “wealth” to the rest of the world. The best studied and understood blue carbon ecosystems are on or near the coast; they are mangrove forests (yes, trees can grow underwater), salt marshes, and seagrass beds. All of these have a supercharged ability to pull carbon dioxide out of the air and convert it into organic carbon. For example, seagrasses capture carbon up to 30 times faster than a rainforest. The rich deposits of blue carbon accumulated by coastal ecosystems are mostly found in the roots and the soil, and can extend up to almost 20 feet (6 meters) below the seabed and remain locked away there for millennia.

We get a wealth of environmental and societal benefits from blue carbon ecosystems beyond managing the global climate — mangrove trees protect shorelines from storm surges, support alternative livelihoods, and enhance local fisheries. And underwater webs of mangrove roots offer a safe haven to countless ocean babies, including newborn lemon shark pups that are only seven centimeters long, along with vulnerable goliath grouper fish that stay in their mangrove nursery for up to six years.

A juvenile lemon shark swimming in the mangroves · Anita Kainrath

What needs to happen next

Climate solutions anchored in the ocean could provide 20% of the carbon reductions needed to meet the Paris Agreement goals by 2050, lowering greenhouse gas emissions by up to 4 billion tons of carbon dioxide equivalent in 2030 and up to 11 billion tons in 2050. To put into perspective how important this is, reductions at this scale amount to the same as stopping the annual emissions from 2.5 billion cars or all of the world’s coal-fired power plants.

Conserving the “big three” blue carbon ecosystems of mangrove trees, salt marshes, and seagrass beds is one of the top five ways for the ocean to deliver on this promise. So how do we get there?

Flock of wading birds on a salt marsh on the Essex coast, UK · Chris Lawrence

1. Protect what we’ve got left

First, we protect all the blue carbon still safely locked away. When mangrove trees or salt marshes are bulldozed to make way for coastal development or seagrass meadows up to hundreds of thousands of years old are devastated by bottom trawling, vast quantities of the stored carbon are released into the atmosphere very quickly, worsening the effects of climate change.

At least 35% of mangroves have already been lost since 1980, and between 2000 and 2015, up to 122 million tons of carbon went out into the atmosphere as a direct consequence of mangrove trees being cut down, roughly equivalent to the annual emissions of Brazil. Protecting what we have left is essential to slow down climate change and stop further emissions from deforestation.

A seagrass bed in the Itchetucknee River, Florida, U.S. · James White & Danita Delimont

2. Restore what we’ve lost

Second, we restore blue carbon ecosystems that have been degraded or destroyed by investing in high-quality planting and restoration programs, with these efforts enabling us to remove excess carbon pollution and prevent our planet from heating up irreversibly.

Planting just ten new mangrove trees leads to the removal of roughly 3 tonnes of carbon dioxide over their growth lifetime, equal to around 30,000 miles flown. Imagine how big an investment we’re making in our collective future by planting over a quarter of a million new mangrove seedlings — a feat that Only One members, each funding between 10 and 10,000 ocean trees each, achieved in just one month in June of this year. And we’re not stopping there!

Mangrove planting in Mozambique · Eden Reforestation Projects

The buzz around blue carbon

All the evidence tells us that boosting initiatives to save blue carbon ecosystems is key to tackling climate change. As things stand, these natural spaces are being degraded or destroyed four times more quickly than tropical forests, with climate change threatening to cause even more losses. But on the flip side, we are seeing signs of positive progress around the world.

The recent UN Ocean Conference, where the Only One team was on the ground, shone a light on ocean solutions like blue carbon capture and storage on a truly international stage. 2022 is fast becoming a “super year for the ocean,” with blue carbon generating a lot of buzz and bold commitments being made to “science-based and innovative actions to address the ocean emergency.” Just last week, the UK announced its intention to become the first nation in the world to map its blue carbon stores, paving the way for the fulfillment of its net-zero targets and the protection of at least 30% of its waters.

A scientist collecting a sediment core to assess carbon storage rates of a tidal seagrass bed in Williamstown, Australia · Izzet Noyan

Tapping into blue carbon to save the planet

With a monthly subscription to Only One, the power to fix the climate through blue carbon solutions is in your hands. One of our carbon reduction partners, Stand For Trees, is preventing 110 million tons of carbon from entering our atmosphere by helping preserve a ridge-to-reef watershed in Cambodia that includes over 2,000 hectares of pristine mangrove forest. Importantly, Stand For Trees’ project is certified by the Verified Carbon Standard (VCS) and has achieved CCB Gold Level status for providing exceptional climate, community, and biodiversity benefits. With just the tap of a button, everyone can start removing carbon pollution and harnessing the power of blue carbon to save the planet.

We hope you now love blue carbon as much as all of us here at Only One do!

Aiisha Photography

How you can help


Choose to balance your carbon footprint on Only One with a monthly membership. You’ll have the option to reduce carbon equal to between 3,000 and 20,000 miles flown every month!


Dive deeper into the extraordinary benefits of blue carbon by reading the article written for us by leading expert Emily Pidgeon. The Blue Carbon Initiative is another great source of information.


Tell anyone and everyone you know about how blue carbon can help fix the climate! The more people who become advocates for this vital climate solution, the better. Why not start by sharing this article on your social media or forwarding it to your friends and family in an email?


Zoë Sanders

Senior Manager of Impact Communications

An arts writer who later fell under the ocean’s spell and never looked back, Zoë loves going cold water swimming in the sea in her home city on the south east coast of England.

Brighton & Hove, England

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