Environmental Science
Understanding Carbon Sequestration
Quick fact
The world's oceans absorb about 25% of the CO₂ released by human activities each year, making them the largest active carbon sink on Earth.
Why this is interesting
Every breath you take adds carbon dioxide to the air. But have you ever wondered where all that CO₂ goes—and how we can help it stay there instead of warming the planet?
Read the full explanation
Understanding Understanding Carbon Sequestration
Imagine the Earth breathing. Plants inhale CO₂ from the air and, using sunlight, transform it into food and grow. This is photosynthesis, a natural carbon capture process. Much of that carbon stays in the plant's wood, roots, and leaves, or gets stored in the soil when the plant dies. Similarly, oceans dissolve CO₂ from the atmosphere, and tiny marine organisms lock it into shells that eventually settle on the seafloor. These natural 'sinks' keep carbon out of the air, slowing climate change. Some of it even gets buried for millions of years, becoming coal, oil, or natural gas. Carbon sequestration is simply the name for all the ways carbon is captured and tucked away—by nature or by human technology—so it can't warm the climate.
A deeper explanation
Carbon sequestration works by moving carbon from the fast cycle (atmosphere, plants, oceans) into long-term storage (soils, deep oceans, geological formations, or durable materials). The underlying principle is that atmospheric CO₂ is a potent greenhouse gas; reducing its concentration mitigates the greenhouse effect. Natural sequestration relies on biological processes: plants turn CO₂ into biomass via photosynthesis, and soils store organic carbon. In oceans, physical dissolution and biological pumps transfer carbon to deep waters. Human-enhanced methods include reforestation, bioenergy with carbon capture and storage (BECCS), and direct air capture (DAC) combined with geological injection. The effectiveness of sequestration depends on permanence, capacity, and leakage risks. Understanding this mechanism is crucial because even aggressive emissions cuts won't be enough to stabilize climate without actively drawing down existing CO₂. Carbon sequestration thus forms a key pillar of climate strategy, alongside reducing emissions and adapting to changes.