Carbon Sequestration

This page last reviewed August 31, 2015

What is Carbon Sequestration?

Carbon sequestration is a term used to describe processes by which carbon dioxide (CO2) is either removed from the atmosphere or captured and diverted from an emissions source for long-term storage. There are two primary kinds of carbon sequestration: biological carbon sequestration (also referred to as terrestrial) and carbon capture and sequestration (CCS). These methods of sequestering carbon have the potential to help California achieve its greenhouse gas reduction goals.


Biological Sequestration is typically accomplished through conservation practices that enhance the storage of carbon (such as restoring forests, wetlands, and grasslands) or reduce CO2 emissions (such as reducing agricultural tillage and suppressing wildfires). Soil carbon sequestration is the process of removing CO2 from the atmosphere by plants accumulating organic matter in soil. For example, when plant materials and roots are decomposed by microbial action (microbes and macrofauna, such as worms), stable forms of carbon in soil are created. In agriculture, soil carbon sequestration can be achieved by land management practices, such as planting cover crops, and incorporating crop residues into the soil. However, the amount of carbon sequestered at a site depends on a balance between incorporation and release mechanisms. Land use, disease, tillage, erosion, and disturbances magnified by climate pressures such as wildfires and droughts can release biologically sequestered CO2 back into the atmosphere. Therefore, efforts to increase biological sequestration are focused on increasing carbon storage, while simultaneously avoiding disturbances that cause CO2 emissions. For more information, visit ARB's Forestry and Natural and Working Lands page.


Carbon Capture and Sequestration (CCS) is any industrial process that diverts CO2 from emission to the atmosphere and sequesters those emissions. CCS includes geologic sequestration, which generally begins with CO2 capture at an emissions source (such as the smoke stack of a power plant, oil refinery, or cement plant) and transportation of compressed CO2 (usually via pipeline) to a storage site. The CO2 is then injected deep into rock formations where it could potentially remain for millennia. While this form of carbon sequestration is not widely utilized at the present, research and demonstrations are being conducted to advance CSS knowledge. Studies indicate that a significant fraction of future carbon emissions from large industrial sources could be captured and diverted from the atmosphere using CCS. For more information, visit ARB's Carbon Capture and Sequestration page.

References and Additional Information

Carbon Capture and Sequestration Technologies Program at MIT

Climate Change and Forestry in California

IPCC report on Carbon Dioxide Capture and Storage

US Environmental Protection Agency (US EPA)

US Geological Survey (USGS)

West Coast Regional Carbon Sequestration Partnership (WESTCARB)

Related Links

California Climate Change Portal:

Cap-and-Trade Program
Carbon Capture and Storage Review Panel
Low Carbon Fuel Standard (LCFS)

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Name: Dave Mallory
Agency: California Air Resources Board
Phone #: (916) 445-8316
E-mail Address:


Name: Alexander "Lex" Mitchell
Agency: California Air Resources Board
Phone #: (916) 327-1513
E-mail Address: