cdrtechs

For reference: over the past decade, human activities have produce approximately 34 GtCO2/yr annually with about 16 GtCO2/yr accumulating in the atmosphere (Global Carbon Budget, 2014)

CDR Method Rate of Capture or Sequestration Bioenergy with Capture 15-18 gigatonnes (Gt) of CO2 per year (theoretical) Geologic Sequestration 1-20 GtCO2 / year Direct Air Capture 10 GtCO2 / year (U.S. only) Land Management 2-5 GtCO2 / year Accelerated Weathering: Land 2 GtCO2 / year Accelerated Weathering: Ocean 1 GtCO2 / year

Land ManagementChanges in the way that land is managed and used can change the amount of carbon dioxide it absorbs. Replanting trees in forests that have been cleared (reforestation) or planting trees on previously open land (afforestation) increases the amount of carbon dioxide the forest can pull out of the atmosphere. Another strategy is planting agricultural lands with cover crops that take up particularly high amounts of carbon dioxide--such as beans, lentils, or alfalfa-- and then leaving the crops to rot in the field, a practice that locks the carbon dioxide away in the soil.EndFragment

Land Management

Cost

Direct Air Capture with Reliable Storage

* globally, except for direct air capture which reflects rates in the U.S only

This page is derived from the 2015 National Academies report Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration. It provides a high-level overview of various approaches to carbon dioxide removal and sequestration, as well as associated estimates for cost and rate of capture and/or sequestration.

Accelerated Weathering

Techniques for Carbon Dioxide Removal and Sequestration

Maximum Potential Rate of Capture or Sequestration*

Blue Carbon

Bioenergy with Carbon Capture and Reliable Storage

Accelerated WeatheringCarbon dioxide in the atmosphere eventually dissolves into ocean water and, through a series of chemical reactions, ends up as carbonate sediments on the ocean floor. This takes thousands of years, but adding crushed alkalinity containing calcium or magnesium minerals could speed up the reactions and increase the amount of carbon dioxide the ocean can absorb. These weathering reactions could also take place on land. Carbonate and/or silicate weathering reactions may be accelerated so that carbon dioxide may be stored on land in the form of calcium or magnesium carbonate solid. EndFragment

Blue CarbonBlue Carbon refers to the potential for coastal ecosystems—for example, vegetation of tidal marsh, seagrass and mangrove habitats—to remove carbon dioxide from the atmosphere and water column and store it in the plants and sediments of these ecosystems. EndFragment

This information on this page is derived from Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration (2015). Blue carbon was not considered in that report, so there is no information available from an Academies-reviewed report on cost or rate of capture or sequestration for this technique.

Bioenergy with Carbon Capture and Reliable Storage (BECCS)BECCS is a process by which biomass is converted to heat, electricity, or liquid or gas fuels, followed by CO2 capture and sequestration. Biomass such as woody plants take up take up carbon dioxide from the atmosphere as they grow. Then, they are processed (to reduce moisture content and incombustible components) and burned in powerplants to produce electricity. The carbon dioxide generated as the biomass burn is captured and stored deep underground. EndFragment

Direct Air Capture with Reliable Storage (DACS)Direct air capture refers to chemical scrubbing processes for capturing CO2 directly from the atmosphere via absorption or adsorption separation processes. Although other abiotic (and biotic) processes can also directly remove CO2 from air.Carbon dioxide is removed from the atmosphere as air passes through large “scrubbers”— air filtering structures located on land –– and then moves underground where it is stored.EndFragment

CDR Method Cost Geologic Sequestration $10-20 per tonne (t) of CO2 Land Management $1-100 / tCO2 Accelerated Weathering: Ocean $50-100 / tCO2 Bioenergy with Capture around $100 / tCO2 Direct Air Capture $400-1000 / tCO2 Accelerated Weathering: Land $20-1000 / tCO2

Direct Air Capture with Reliable Storage (DACS)Direct air capture refers to chemical scrubbing processes for capturing CO2 directly from the atmosphere via absorption or adsorption separation processes. Although other abiotic (and biotic) processes can also directly remove CO2 from air,Carbon dioxide is removed from the atmosphere as air passes through large “scrubbers”— air filtering structures located on land –– and then moves underground where it is stored.EndFragment