Fish swimming around a colorful coral reef in the ocean
Tom Clynes 3 minute read

The incredible climate-saving power of the world's oceans and wetlands


Carbon that’s captured and stored by the world's ocean and coastal ecosystems is known as blue carbon. Marine environments have absorbed about a third of human carbon emissions since the start of the Industrial Revolution. 

But as they are degraded or destroyed, they lose their ability to trap carbon and can release it into the atmosphere, accelerating climate change. Scientists are studying these processes in an effort to build the case for preservation.

Coastal wetlands

Mangrove forests, salt marshes and seagrass meadows sequester carbon 10 times faster than mature tropical forests, but they are disappearing four times faster. Fast-growing coastal wetland plants take in CO2 during photosynthesis and deposit carbon-containing leaves, branches and roots in underwater sediment. In this oxygen-poor environment, plant materials decompose slowly and can persist for thousands of years. But development, overfishing and other pressures can transform coastal environments from sinks to sources of CO2 as well as methane, another potent greenhouse gas.

Let's explore these extraordinary ecosystems:

Open oceans

The ocean collects and stores vast amounts of carbon in seabed sediment, vegetation, marine animals and the seawater itself. But warming waters and unsustainable exploitation can disrupt deep-water carbon cycles and release long-trapped gas back into the atmosphere.

Check out the incredible carbon-storing plants, waters and mammals that make up this extraordinary system:

Hope for a warming planet

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