Carbon Sequestration Explained: How CO₂ Gets Stored

Sequestration is the capture and long-term storage of CO₂. It comes in two broad flavours. Biological sequestration uses living systems — forests, grasslands, wetlands and soils — to pull carbon out of the air through photosynthesis. Geological and technological sequestration captures CO₂ and locks it into rock, deep formations, or stable materials.

Natural sinks already do enormous work: the world’s forests and oceans absorb roughly half of human emissions every year. The question for climate funding is how to protect and extend that capacity — and how to add durable, engineered storage on top.

Not all stored carbon stays stored. A newly planted forest may hold carbon for decades, but a fire, drought or chainsaw can release it again. That is why the field talks about permanence — the length of time carbon is reliably kept out of the atmosphere.

Durable methods sit at the other end of the spectrum. Biochar stabilises carbon in a form that resists decay for centuries; mineralisation and geological storage can hold it effectively forever. We weight our funding toward options we can actually verify and trust.

It helps to separate two ideas. Sequestration is a physical process — carbon goes in, carbon stays. “Offsetting” is an accounting claim layered on top: that a tonne stored cancels a tonne you emitted. The science of storage can be solid even when the accounting claim is shaky, which is exactly why we focus on funding verified removal rather than selling a tidy cancel-out.