advancing the mitigation of Climate Change and Global Warming through Geoengineering education and research

Carbon Dioxide Removal

Carbon Dioxide Removal (CDR) is a geoengineering or climate engineering approach that focuses on removing carbon dioxide from the atmosphere to limit and/or reverse Global Warming and Climate Change. The goal of this approach is to offset the carbon dioxide emissions that are currently being produced by the burning of fossil fuels, reduce the amount of carbon dioxide that is stored in the atmosphere and oceans, and reverse the impacts of high concentrations of carbon dioxide in our biosphere such as ocean acidification. Proposed Carbon Dioxide Removal methodologies include:

Direct Air Capture approaches remove carbon dioxide directly from the air or atmosphere, compress the CO2 into a liquid, and store the liquid CO2 underground or use the CO2 in carbon-neutral fuels or products.

Carbon Capture and Storage methodologies focus on reducing the CO2 emissions of coal power plants and other fossil fuel-based energy producing facilities. Carbon Capture and Storage methodologies capture CO2 in pre or post-combustion processes and either store the CO2 underground or use it in carbon-neutral products.

Biochar is a solution to Global Warming that removes carbon dioxide from the atmosphere by burying charcoal in the soil. Plants and trees remove carbon dioxide from the atmosphere. This plant material or biomass is then burned under low-oxygen conditions to produce charcoal. The charcoal (generally ground up into small particles) is then buried in the soil of agricultural fields to sequester carbon for hundreds of years. The Aztecs, in fact, used biochar to improve the fertility of the soil in their agricultural fields.

Enhanced Weathering is a geoengineering carbon dioxide removal approach that utilizes chemical reactions between rocks/minerals and CO2 to reduce CO2 in the atmosphere. To carry out Enhanced Weathering, silicate (or carbonate) containing rocks such as olivine are ground up into a powder and incorporated into the soils of agricultural areas (or on beaches). The silicate containing rock powder reacts with water and CO2 to form bicarbonate ions (HCO3-). This reaction effectively removes CO2 from the atmosphere. The bicarbonate ions, which are dissolved in water, eventually end up in the ocean where calcifying organisms (such as corals and some plankton) convert the bicarbonate to calcium carbonate (CaCO3). The calcium carbonate eventually sinks to the bottom of the ocean.

Ocean Fertilization is an approach that removes CO2 from the atmosphere with planktonic communities. In areas of the ocean where upwelling occurs (and other areas of the ocean), nutrients are often limited and restrict the growth of photosynthetic planktonic plants or algae. By fertilizing these areas, large numbers of planktonic algae can then absorb CO2 to grow and build biomass. When the algae die and their biomass sinks to the bottom of the ocean, the carbon dioxide they absorbed is removed from the atmosphere for extremely long periods of time.

Ecosystem Restoration removes carbon dioxide from the atmosphere by storing the carbon in plants and animals. Large areas of the Earth are degraded and deforested. When these ecological communities are restored they absorb and store large amounts of carbon dioxide in plant and animal biomass.

Blue Carbon is a natural climate solution to mitigate and reverse the effects of Global Warming. Blue Carbon Ecosystems are coastal and marine communities including saltmarshes, seagrass meadows, mangrove forests and kelp forests. These communities absorb and store large quantities carbon in their tissues and soils. Conserving and restoring Blue Carbon Ecosystems is an excellent way to remove CO2 from the atmosphere and store it for long periods.