Carbon sequestration is the process of storing carbon in a carbon pool. It plays a crucial role in mitigating climate change by reducing the amount of carbon dioxide in the atmosphere. There are two main types of carbon sequestration: biologic and geologic. Biologic carbon sequestration is a naturally occurring process as part of the carbon cycle. Humans can enhance it through deliberate actions and use of technology. Carbon dioxide is naturally captured from the atmosphere through biological, chemical, and physical processes. These processes can be accelerated for example through changes in land use and agricultural practices, called carbon farming. Artificial processes have also been devised to produce similar effects. This approach is called carbon capture and storage. It involves using technology to capture and sequester (store) CO2 that is produced from human activities underground or under the sea bed.

A carbon sink is a natural or artificial process that "removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere". These sinks form an important part of the natural carbon cycle. An overarching term is carbon pool, which is all the places where carbon on Earth can be, i.e. the atmosphere, oceans, soil, plants, and so forth. A carbon sink is a type of carbon pool that has the capability to take up more carbon from the atmosphere than it releases.