Sequestration refers to the process of storing or “locking” carbon from the Earth’s atmosphere into plants, soils, rocks, oceans and the built environment.
Carbon sequestration happens all the time. Plants draw carbon out of the atmosphere and use it to grow their leaves, branches, trunks and roots. Over time, some of that carbon ends up deep in the soil for a very long time.
Oceans and rocks also naturally sequester carbon, and have been doing so for millions of years.
Sequestration can be encouraged. Planting more trees or expanding areas of forests, grasslands or wildlands would allow more plants to grow and draw down greater amounts of carbon dioxide. Some of that carbon will be transferred into the ground.
Sequestration can also be encouraged through sustainable agricultural practices, such as zero- or low-till farming or through the use of agricultural biochar.
Carbon from the atmosphere can be captured – from emissions or directly from the atmosphere – and pumped deep underground as liquid carbon dioxide.
Such technologies are interesting, but there is active debate around the cost, feasibility and consequences of adopting them at scale. Still, if we fail to manage our current carbon emissions we may have no choice.