Two main types of carbon sequestration are terrestrial and geologic, according to Plains CO2 Reduction Partnership. Terrestrial methods use plants to capture CO2 from the atmosphere, and geologic sequestration involves putting the substance into long-term underground storage. A third method uses the mineral serpentinite and carbon dioxide to form magnesium.
Terrestrial sequestration stores the carbon taken from captured carbon dioxide in the soil and the roots and stems of plants. Geologic sequestration captures carbon dioxide before it is released into the atmosphere from anthropogenic sources and transports it deep underground to aging oil fields or saline aquifers. Because CO2 is heavier than water, and it remains in liquid forms at great depths, pumping it to the bottom of the ocean is another possibility.