Carbon dioxide removal (CDR) is a process in which carbon dioxide is proactively removed from the atmosphere and sequestered for long periods of time.
The Intergovernmental Panel on Climate Change (IPCC) released a report in 2021 which estimated that in order to limit global warming to 1.5 °C or 2 °C the world will need to invest in carbon removal technologies alongside the reduction of overall emissions.
There are multiple methods of removing carbon from the air that can be divided into either natural or technological solutions. Some of the natural solutions include afforestation, reforestation, and forestry management, while the technological solutions include bioenergy with carbon capture and storage (BECCS), a process of extracting bioenergy from biomass and capturing and storing the carbon, or direct air capture (DAC) where carbon dioxide is captured from the ambient air, compressed and then stored.
The longevity of the sequestration process depends on the particular method of capturing and storing the carbon. Forests can have a lifespan from a few dozen years, while storing carbon deep underground can remove it from the atmosphere for millenia.