Definition 1
Carbon Sequestration means the natural or technological process of:
(a) removing carbon dioxide from the atmosphere at the emissions source; and
(b) [permanently] storing such carbon dioxide.
Drafting notes and guidance
Carbon sequestration refers to the removal and storage of carbon dioxide from the atmosphere.
Carbon sequestration is closely linked to Carbon Capture and Storage ( CCS ) and Carbon Capture Usage and Storage ( CCUS ), both of which use technology to limit emissions resulting from the continued use of fossil fuels. Carbon sequestration is a category of CCS/ CCUS but is defined separately because it can be a natural process.
Methods of carbon sequestration
Technological carbon sequestration involves capturing and storing carbon dioxide through technology. Direct air capture ( DAC ) is an example of technological carbon sequestration. This involves capturing carbon dioxide directly from the air using advanced technology plants and then storing it in deep geological formations (see below).
Geological carbon sequestration is the injection of highly pressurised carbon dioxide into rock layers deep beneath the Earth’s surface. This method is thought to be reasonably permanent. Most articles that refer to sequestration are referring to geological carbon sequestration.
Natural carbon sequestration is the storage of carbon dioxide by natural means, including through the ocean, soil, geological formations, or vegetation (forests, grasslands, etc).
Afforestation relates to planting forests on lands that was not previously forested. Though it has the potential to capture huge amounts of carbon, this is an unreliable way of permanently sequestering carbon. Wildfires during the burning season in 2021 and 2022 have caused the loss of many afforestation projects designed to sequester carbon.
Retention does not happen for at least 10 years after the trees are planted. Forests must be maintained for 100 years to be effective carbon stores (eg. not get burned or cut down, releasing the contained carbon back into the atmosphere). This will require intergenerational maintenance by sufficiently well-resourced individuals and/ or management organisations.
Soil sequestration is the method by which carbon dioxide is drawn into the earth through regenerative agricultural techniques. It is considered to be more effective than afforestation because the carbon remains in the soil for hundreds of years. It also acts as a highly effective fertiliser. This reduces the need for synthetic fertilisers, the production of which generates large amounts of emissions.