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Deploy Ocean Alkalinity Enhancement

Keep Watching
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An image of the frothy crest of a wave

Ocean alkalinity enhancement (OAE) increases the ocean’s natural ability to remove CO₂ from the air by increasing the alkalinity of ocean water. This carbon removal practice could be globally effective at removing CO₂ at the gigaton level annually and is currently being tested in field studies. Advantages of OAE include its ability to mitigate ocean acidification where it’s deployed and its scalability. Disadvantages include uncertainties surrounding OAEs' global effectiveness and feasibility, potential impacts on marine life and humans, complex monitoring needed for verification, and potentially high costs, all of which need to be more closely studied. We conclude that Deploy Ocean Alkalinity Enhancement is “Worth Watching” until the technology advances and its risks, costs, and benefits become clearer.

Last updated June 30, 2025

What is our assessment?

Based on our analysis, OAE could be a promising carbon removal technique, but it is not ready for large-scale deployment until the risks, costs, and effectiveness become clearer. This potential climate solution is “Worth Watching.”

Plausible Could it work? Yes
Ready Is it ready? No
Evidence Are there data to evaluate it? Limited
Effective Does it consistently work? No
Impact Is it big enough to matter? Yes
Risk Is it risky or harmful? ?
Cost Is it cheap? ?

What is it?

OAE is the practice of adding alkalinity to seawater to increase the ocean’s ability to remove atmospheric CO₂. The addition of alkalinity through OAE mimics the natural process of weathering, or the physical and chemical breakdown of rocks. Rock weathering on land produces alkaline substances that eventually flow into the ocean through rivers and groundwater. This natural supply of alkalinity reduces ocean acidity, which affects the distribution of various carbon forms in the ocean. As alkalinity increases, CO₂ dissolved in seawater shifts toward more stable carbon forms, like bicarbonate and carbonate ions, that cannot exchange with air. This allows the ocean to remove more gaseous CO₂ from the atmosphere because the ocean and the atmosphere maintain a balance of CO₂ through gas movement at the sea surface. Most of the dissolved carbon in the ocean is bicarbonate and carbonate ions, which can persist in seawater for thousands of years. Under natural conditions, the ocean removes nearly 0.5 Gt of CO₂ annually. OAE generally relies on dissolving large amounts of ground-up rocks, either directly in the ocean or indirectly in water that is added to the ocean, to increase alkalinity and remove CO₂. This practice typically requires mining for alkaline rocks, though alkaline materials can also be sourced from waste by-products of other industries (e.g., steel slag, mine tailings) or commercially through human-made substances.

Does it work?

The science behind OAE is theoretically sound, and OAE is expected to result in durable storage over long time periods (>100 years). At scale, OAE could potentially remove over 1 Gt CO₂ /yr, but additional lab and field-based studies are needed to understand whether this approach is effective and safe. The majority of our understanding of OAE comes from models and laboratory experiments. However, when crushed minerals have been dispersed in field studies, the dissolution has not always occurred as expected. Several large-scale experimental trials are currently underway or planned, which will produce real-world data and inform monitoring and verification tactics needed to help refine and guide future implementation. These tests will also provide critical information on any ecological or community impacts. Various ways of implementing OAE are being developed, including ship-based dispersal, shoreline-based systems, and other approaches that leverage existing industrial waste streams or combine with other marine carbon dioxide removal (mCDR) techniques, such as electrochemical alkalinity generation.

Why are we excited?

OAE removes CO₂ from the atmosphere and stores it in the ocean as bicarbonate and carbonate ions, which are stable over long time periods. This means the CO₂ would be durably stored from the atmosphere for thousands of years. OAE could be scaled globally and can also mitigate local ocean acidification, a growing issue that threatens a range of marine ecosystems. Indeed, adding alkalinity to seawater has already been shown to mitigate ocean acidification in some coral reefs. Mitigating ocean acidification could also benefit fisheries and aquaculture, highlighting the potential for OAE to provide additional local benefits beyond carbon removal.

Why are we concerned?

Several technical, environmental, and social concerns surround OAE. The effectiveness could be limited by real-world conditions that either transport the alkaline materials away from the ocean’s surface before CO₂ can be absorbed or result in unexpected chemical reactions or biological uptake of the added alkalinity. Measuring and verifying the amount of CO₂ permanently stored using OAE is also challenging and will rely on a combination of field data and complex numerical models, which will require significant effort to collect and develop. Beyond these technical challenges, OAE poses potential environmental risks on land and in the ocean. On land, OAE could require an expansion of mining that rivals the cement industry, which could have negative environmental impacts on human and ecosystem health. In the ocean, increased alkalinity and the potential release of metals from the source rocks could negatively affect some marine life, but our understanding of the effects on individual species and food webs is limited. OAE could also interfere with existing ocean uses (e.g., fisheries, recreation) in some places and could have other unintended consequences as well. For instance, research suggests that OAE reduces natural alkalinity production in some ocean areas. In addition, OAE faces several social challenges. To be successful, mCDR approaches, like OAE, will require rapid, meaningful, and just community engagement. Public concerns about OAE have already led to a pilot project cancellation, highlighting the importance of public perception for OAE feasibility. It is also unclear if OAE can be scaled globally at reasonable costs, with current estimates highly variable but generally over US$100/t CO₂. Lastly, acquiring and dispersing sufficient alkaline materials could be challenging at scale, particularly because some materials are currently energy-intensive to source, transport, and/or produce.

References

Albright, R., Caldeira, L., Hosfelt, J., Kwiatkowski, L., Maclaren, J. K., Mason, B. M., ... & Caldeira, K. (2016). Reversal of ocean acidification enhances net coral reef calcification. Nature, 531(7594), 362-365. https://doi.org/10.1038/nature17155 

Bach, L. T. (2024). The additionality problem of ocean alkalinity enhancement. Biogeosciences, 21(1), 261-277. https://doi.org/10.5194/bg-21-261-2024 

Bach, L. T., Gill, S. J., Rickaby, R. E., Gore, S., & Renforth, P. (2019). CO₂ removal with enhanced weathering and ocean alkalinity enhancement: potential risks and co-benefits for marine pelagic ecosystems. Frontiers in Climate, 1, 7. https://doi.org/10.3389/fclim.2019.00007 

Bertram, C., & Merk, C. (2020). Public perceptions of ocean-based carbon dioxide removal: the nature-engineering divide?. Frontiers in Climate, 2, 594194. https://doi.org/10.3389/fclim.2020.594194 

(carbon)plan. Introduction to Ocean Alkalinity Enhancement: https://carbonplan.org/research/oae-efficiency-explainer 

Carbon Herald. (2025, April 11). Planetary Technologies cancels its mCDR project in Cornwall. https://carbonherald.com/planetary-technologies-cancels-its-mcdr-project-in-cornwall/ 

Doney, S. C., Wolfe, W. H., McKee, D. C., & Fuhrman, J. G. (2024). The science, engineering, and validation of marine carbon dioxide removal and storage. Annual Review of Marine Science, 17. https://doi.org/10.1146/annurev-marine-040523-014702 

Doney, S. C., Fabry, V. J., Feely, R. A., & Kleypas, J. A. (2009). Ocean acidification: the other CO₂ problem. Annual Review of Marine Science, 1(1), 169-192. https://doi.org/10.1146/annurev.marine.010908.163834

EGU Biogeosciences. Special Issue: Environmental impacts of ocean alkalinity enhancement. https://bg.copernicus.org/articles/special_issue1246.html 

Gattuso, J. P., Magnan, A. K., Bopp, L., Cheung, W. W., Duarte, C. M., Hinkel, J., ... & Rau, G. H. (2018). Ocean solutions to address climate change and its effects on marine ecosystems. Frontiers in Marine Science, 5, 337. https://doi.org/10.3389/fmars.2018.00337 

Oschlies, A., Stevenson, A., Bach, L. T., Fennel, K., Rickaby, R. E. M., Satterfield, T., Webb, R., and Gattuso, J.-P. (2023). Guide to Best Practices in Ocean Alkalinity Enhancement Research, Copernicus Publications, State of the Planet, 2-oae2023. https://doi.org/10.5194/sp-2-oae2023 

Hartmann, J., Suitner, N., Lim, C., Schneider, J., Marín-Samper, L., Arístegui, J., ... & Riebesell, U. (2022). Stability of alkalinity in ocean alkalinity enhancement (OAE) approaches–consequences for durability of CO 2 storage. Biogeosciences Discussions, 2022, 1-29. https://doi.org/10.5194/bg-20-781-2023

Hartmann, J., West, A. J., Renforth, P., Köhler, P., De La Rocha, C. L., Wolf‐Gladrow, D. A., ... & Scheffran, J. (2013). Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Reviews of Geophysics, 51(2), 113-149. https://doi.org/10.1002/rog.20004

He, J., & Tyka, M. D. (2023). Limits and CO₂ equilibration of near-coast alkalinity enhancement. Biogeosciences, 20(1), 27-43. https://doi.org/10.5194/bg-20-27-2023

National Academies of Sciences, Engineering, and Medicine; Division on Earth and Life Studies; Ocean Studies Board; Committee on A Research Strategy for Ocean-based Carbon Dioxide Removal and Sequestration. A Research Strategy for Ocean-based Carbon Dioxide Removal and Sequestration. Washington (DC): National Academies Press (US); 2021 Dec 8. 7, Ocean Alkalinity Enhancement. Available from: https://www.ncbi.nlm.nih.gov/books/NBK580052/ 

Ocean Visions: https://oceanvisions.org/ocean-alkalinity-enhancement/ 

Palmiéri, J. and Yool, A., 2024. Global‐scale evaluation of coastal ocean alkalinity enhancement in a fully coupled Earth system model. Earth's Future, 12(3), p.e2023EF004018. https://doi.org/10.1029/2023EF004018

Renforth, P., & Henderson, G. (2017). Assessing ocean alkalinity for carbon sequestration. Reviews of Geophysics, 55(3), 636-674. https://doi.org/10.1002/2016RG000533 

Satterfield, T., Nawaz, S., & Boettcher, M. (2023). Social considerations and best practices for engaging publics on ocean alkalinity enhancement. State of the Planet Discussions, 2023, 1-39. https://doi.org/10.5194/sp-2-oae2023-11-2023 

Webb, R. M., Silverman-Roati, K., & Gerrard, M. B. (2021). Removing Carbon Dioxide Through Ocean Alkalinity Enhancement: Legal Challenges and Opportunities. Available at: https://scholarship.law.columbia.edu/faculty_scholarship/2981 

Zhuang, W., Zhu, T., Li, F., Queiroz, H. M., Yan, Q., Zhao, X., & Liu, J. (2025). Potential Environmental Impacts and Management Strategies for Metal Release during Ocean Alkalinity Enhancement Using Olivine. Environmental Science & Technology, 59(2), 1091-1099. https://doi.org/10.1021/acs.est.4c10705 

Zhou, M., Tyka, M. D., Ho, D. T., Yankovsky, E., Bachman, S., Nicholas, T., ... & Long, M. C. (2024). Mapping the global variation in the efficiency of ocean alkalinity enhancement for carbon dioxide removal. Nature Climate Change, 15(1), 59-65. https://doi.org/10.1038/s41558-024-02179-9 

Credits

Lead Fellow 

  • Christina Richardson

Internal Reviewer

  • Christina Swanson
  • Greenhouse gas quantity expressed relative to CO₂ with the same warming impact over 100 years, calculated by multiplying emissions by the 100-yr GWP for the emitted gases.

  • Greenhouse gas quantity expressed relative to CO with the same warming impact over 20 years, calculated by multiplying emissions by the 20-yr GWP for the emitted gases.

  • Reducing greenhouse gas concentrations in the atmosphere by preventing or reducing emissions.

  • The process of increasing the acidity of water or soil due to increased levels of certain air pollutants.

  • Benefits of climate solutions that extend beyond their ability to reduce emissions or store carbon (e.g., benefits to public health, water quality, biodiversity, advancing human rights).

  • The extent to which emissions reduction or carbon removal is above and beyond what would have occurred without implementing a particular action or solution.

  • An upper limit on solution adoption based on physical or technical constraints, not including economic or policy barriers. This level is unlikely to be reached and will not be exceeded.

  • The quantity and metric to measure implementation for a particular solution that is used as the reference unit for calculations within that solution.

  • Farming practices that work to create socially and ecologically sustainable food production.

  • Addition of trees and shrubs to crop or animal farming systems.

  • Spread out the cost of an asset over its useful lifetime.

  • A crop that live one year or less from planting to harvest; also called annual.

  • black carbon

  • Made from material of biological origin, such as plants, animals, or other organisms.

  • A renewable energy source generated from organic matter from plants and/or algae.

  • An energy source composed primarily of methane and CO that is produced by microorganisms when organic matter decomposes in the absence of oxygen.

  • Carbon stored in biological matter, including soil, plants, fungi, and plant products (e.g., wood, paper, biofuels). This carbon is sequestered from the atmosphere but can be released through decomposition or burning.

  • Living or dead renewable matter from plants or animals, not including organic material transformed into fossil fuels. Peat, in early decay stages, is partially renewable biomass.

  • A type of carbon sequestration that captures carbon from CO via photosynthesis and stores it in soils, sediments, and biomass, distinct from sequestration through chemical or industrial pathways.

  • A climate pollutant, also called soot, produced from incomplete combustion of organic matter, either naturally (wildfires) or from human activities (biomass or fossil fuel burning).

  • High-latitude (>50°N or >50°S) climate regions characterized by short growing seasons and cold temperatures.

  • The components of a building that physically separate the indoors from the outdoor environment.

  • Businesses involved in the sale and/or distribution of solution-related equipment and technology, and businesses that want to support adoption of the solution.

  • A chemical reaction involving heating a solid to a high temperature: to make cement clinker, limestone is calcined into lime in a process that requires high heat and produces CO.

  • A four-wheeled passenger vehicle.

  • Technologies that collect CO before it enters the atmosphere, preventing emissions at their source. Collected CO can be used onsite or in new products, or stored long term to prevent release.

  • A greenhouse gas that is naturally found in the atmosphere. Its atmospheric concentration has been increasing due to human activities, leading to warming and climate impacts.

  • Total GHG emissions resulting from a particular action, material, technology, or sector.

  • Amount of GHG emissions released per activity or unit of production. 

  • A marketplace where carbon credits are purchased and sold. One carbon credit represents activities that avoid, reduce, or remove one metric ton of GHG emissions.

  • A colorless, odorless gas released during the incomplete combustion of fuels containing carbon. Carbon monoxide can harm health and be fatal at high concentrations.

  • Activities or technologies that pull CO out of the atmosphere, including enhancing natural carbon sinks and deploying engineered sinks.

  • Long-term storage of carbon in soils, sediment, biomass, oceans, and geologic formations after removal of CO from the atmosphere or CO capture from industrial and power generation processes.

  • carbon capture and storage

  • carbon capture, utilization, and storage

  • A binding ingredient in concrete responsible for most of concrete’s life-cycle emissions. Cement is made primarily of clinker mixed with other mineral components.

  • methane

  • Gases or particles that have a planet-warming effect when released to the atmosphere. Some climate pollutants also cause other forms of environmental damage.

  • A binding ingredient in cement responsible for most of the life-cycle emissions from cement and concrete production.

  • carbon monoxide

  • Neighbors, volunteer organizations, hobbyists and interest groups, online communities, early adopters, individuals sharing a home, and private citizens seeking to support the solution.

  • A solution that potentially lowers the benefit of another solution through reduced effectiveness, higher costs, reduced or delayed adoption, or diminished global climate impact.

  • A farming system that combines reduced tillage, cover crops, and crop rotations.

  • carbon dioxide

  • A  measure standardizing the warming effects of greenhouse gases relative to CO. CO-eq is calculated as quantity (metric tons) of a particular gas multiplied by its GWP.

  • carbon dioxide equivalent

  • The process of cutting greenhouse gas emissions (primarily CO) from a particular sector or activity.

  • A solution that works slower than gradual solutions and is expected to take longer to reach its full potential.

  • Microbial conversion of nitrate into inert nitrogen gas under low-oxygen conditions, which produces the greenhouse gas nitrous oxide as an intermediate compound.

  • Greenhouse gas emissions produced as a direct result of the use of a technology or practice.

  • Ability of a solution to reduce emissions or remove carbon, expressed in CO-eq per installed adoption unit. Effectiveness is quantified per year when the adoption unit is cumulative over time.

  • Greenhouse gas emissions accrued over the lifetime of a material or product, including as it is produced, transported, used, and disposed of.

  • Solutions that work faster than gradual solutions, front-loading their impact in the near term.

  • Methane produced by microbes in the digestive tracts of ruminant livestock, such as cattle, sheep and goats.

  • environmental, social, and governance

  • exchange-traded fund

  • A process triggered by an overabundance of nutrients in water, particularly nitrogen and phosphorus, that stimulates excessive plant and algae growth and can harm aquatic organisms.

  • The scientific literature that supports our assessment of a solution's effectiveness.

  • A group of human-made molecules that contain fluorine atoms. They are potent greenhouse gases with GWPs that can be hundreds to thousands times higher than CO.

  • food loss and waste

  • Food discarded during pre-consumer supply chain stages, including production, harvest, and processing.

  • Food discarded at the retail and consumer stages of the supply chain.

  • Combustible materials found in Earth's crust that can be burned for energy, including oil, natural gas, and coal. They are formed from decayed organisms through prehistoric geological processes.

  • greenhouse gas

  • gigajoule or billion joules

  • The glass layers or panes in a window.

  • A measure of how effectively a gas traps heat in the atmosphere relative to CO. GWP converts greenhouse gases into CO-eq emissions based on their 20- or 100-year impacts.

  • A solution that has a steady impact so that the cumulative effect over time builds as a straight line. Most climate solutions fall into this category.

  • A gas that traps heat in the atmosphere, contributing to climate change.

  • metric gigatons or billion metric tons

  • global warming potential

  • hectare

  • household air pollution

  • Number of years a person is expected to live without disability or other limitations that restrict basic functioning and activity.

  • A unit of land area comprising 10,000 square meters, roughly equal to 2.5 acres.

  • hydrofluorocarbon

  • hydrofluoroolefin

  • Particles and gases released from use of polluting fuels and technologies such as biomass cookstoves that cause poor air quality in and around the home.

  • Organic compounds that contain hydrogen and carbon.

  • Human-made F-gases that contain hydrogen, fluorine, and carbon. They typically have short atmospheric lifetimes and GWPs hundreds or thousands times higher than CO

  • Human-made F-gases that contain hydrogen, fluorine, and carbon, with at least one double bond. They have low GWPs and can be climate-friendly alternatives to HFC refrigerants.

  • internal combustion engine

  • Greenhouse gas emissions produced as a result of a technology or practice but not directly from its use.

  • Device used to power vehicles by the intake, compression, combustion, and exhaust of fuel that drives moving parts.

  • The annual discount rate that balances net cash flows for a project over time. Also called IRR, internal rate of return is used to estimate profitability of potential investments.

  • Individuals or institutions willing to lend money in search of a return on their investment.

  • internal rate of return

  • A measure of energy

  • International agreement adopted in 2016 to phase down the use of high-GWP HFC F-gases over the time frame 2019–2047.

  • A measure of energy equivalent to the energy delivered by 1,000 watts of power over one hour.

  • kiloton or one thousand metric tons

  • kilowatt-hour

  • A land-holding system, e.g. ownership, leasing, or renting. Secure land tenure means farmers or other land users will maintain access to and use of the land in future years.

  • Gases, mainly methane and CO, created by the decomposition of organic matter in the absence of oxygen.

  • leak detection and repair

  • Regular monitoring for fugitive methane leaks throughout oil and gas, coal, and landfill sector infrastructure and the modification or replacement of leaking equipment.

  • Relocation of emissions-causing activities outside of a mitigation project area rather than a true reduction in emissions.

  • The rate at which solution costs decrease as adoption increases, based on production efficiencies, technological improvements, or other factors.

  • Percent decrease in costs per doubling of adoption.

  • landfill gas

  • Greenhouse gas emissions from the sourcing, production, use, and disposal of a technology or practice.

  • low- and middle-income countries

  • liquefied petroleum gas

  • A measure of the amount of light produced by a light source per energy input.

  • square meter kelvins per watt (a measure of thermal resistance, also called R-value)

  • marginal abatement cost curve

  • Livestock grazing practices that strategically manage livestock density, grazing intensity, and timing. Also called improved grazing, these practices have environmental, soil health, and climate benefits, including enhanced soil carbon sequestration.

  • A tool to measure and compare the financial cost and abatement benefit of individual actions based on the initial and operating costs, revenue, and emission reduction potential.

  • A greenhouse gas with a short lifetime and high GWP that can be produced through a variety of mechanisms including the breakdown of organic matter.

  • A measure of mass equivalent to 1,000 kilograms (~2,200 lbs).

  • million hectares

  • Soils mostly composed of inorganic materials formed through the breakdown of rocks. Most soils are mineral soils, and they generally have less than 20% organic matter by weight.

  • A localized electricity system that independently generates and distributes power. Typically serving limited geographic areas, mini-grids can operate in isolation or interconnected with the main grid.

  • Reducing the concentration of greenhouse gases in the atmosphere by cutting emissions or removing CO.

  • Percent of trips made by different passenger and freight transportation modes.

  • megaton or million metric tons

  • A commitment from a country to reduce national emissions and/or sequester carbon in alignment with global climate goals under the Paris Agreement, including plans for adapting to climate impacts.

  • A gaseous form of hydrocarbons consisting mainly of methane.

  • Chemicals found in nature that are used for cooling and heating, such as CO, ammonia, and some hydrocarbons. They have low GWPs and are ozone friendly, making them climate-friendly refrigerants.

  • Microbial conversion of ammonia or ammonium to nitrite and then to nitrate under aerobic conditions.

  • A group of air pollutant molecules composed of nitrogen and oxygen, including NO and NO.

  • A greenhouse gas produced during fossil fuel combustion and agricultural and industrial processes. NO is hundreds of times more potent than CO at trapping atmospheric heat, and it depletes stratospheric ozone.

  • Social welfare organizations, civic leagues, social clubs, labor organizations, business associations, and other not-for-profit organizations.

  • A material or energy source that relies on resources that are finite or not naturally replenished at the rate of consumption, including fossil fuels like coal, oil, and natural gas.

  • nitrogen oxides

  • nitrous oxide

  • The process of increasing the acidity of seawater, primarily caused by absorption of CO from the atmosphere.

  • An agreement between a seller who will produce future goods and a purchaser who commits to buying them, often used as project financing for producers prior to manufacturing.

  • Productive use of wet or rewetted peatlands that does not disturb the peat layer, such as for hunting, gathering, and growing wetland-adapted crops for food, fiber, and energy.

  • A measure of transporting one passenger over a distance of one kilometer.

  • The longevity of any greenhouse gas emission reductions or removals. Solution impacts are considered permanent if the risk of reversing the positive climate impacts is low within 100 years.

  • A mixture of hydrocarbons, small amounts of other organic compounds, and trace amounts of metals used to produce products such as fuels or plastics.

  • Private, national, or multilateral organizations dedicated to providing aid through in-kind or financial donations.

  • An atmospheric reaction among sunlight, VOCs, and nitrogen oxide that leads to ground-level ozone formation. Ground-level ozone, a component of smog, harms human health and the environment.

  • passenger kilometer

  • particulate matter

  • Particulate matter 2.5 micrometers or less in diameter that can harm human health when inhaled.

  • Elected officials and their staff, bureaucrats, civil servants, regulators, attorneys, and government affairs professionals.

  • System in a vehicle that generates power and delivers it to the wheels. It typically includes an engine and/or motor, transmission, driveshaft, and differential.

  • People who most directly interface with a solution and/or determine whether the solution is used and/or available. 

  • The process of converting inorganic matter, including carbon dioxide, into organic matter (biomass), primarily by photosynthetic organisms such as plants and algae.

  • Defined by the International Union for the Conservation of Nature as: "A clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values". References to PAs here also include other effective area-based conservation measures defined by the IUCN. 

  • Very large or small numbers are formatted in scientific notation. A positive exponent multiplies the number by powers of ten; a negative exponent divides the number by powers of ten.

  • Small-scale family farmers and other food producers, often with limited resources, usually in the tropics. The average size of a smallholder farm is two hectares (about five acres).

  • soil organic carbon

  • Carbon stored in soils, including both organic (from decomposing plants and microbes) and inorganic (from carbonate-containing minerals).

  • Carbon stored in soils in organic forms (from decomposing plants and microbes). Soil organic carbon makes up roughly half of soil organic matter by weight.

  • Biologically derived matter in soils, including living, dead, and decayed plant and microbial tissues. Soil organic matter is roughly half carbon on a dry-weight basis.

  • soil organic matter

  • sulfur oxides

  • sulfur dioxide

  • The rate at which a climate solution physically affects the atmosphere after being deployed. At Project Drawdown, we use three categories: emergency brake (fastest impact), gradual, or delayed (slowest impact).

  • Climate regions between latitudes 23.4° to 35° above and below the equator characterized by warm summers and mild winters.

  • A polluting gas produced primarily from burning fossil fuels and industrial processes that directly harms the environment and human health.

  • A group of gases containing sulfur and oxygen that predominantly come from burning fossil fuels. They contribute to air pollution, acid rain, and respiratory health issues.

  • Processes, people, and resources involved in producing and delivering a product from supplier to end customer, including material acquisition.

  • metric tons

  • Technology developers, including founders, designers, inventors, R&D staff, and creators seeking to overcome technical or practical challenges.

  • Climate regions between 35° to 50° above and below the equator characterized by moderate mean annual temperatures and distinct seasons, with warm summers and cold winters.

  • A measure of how well a material prevents heat flow, often called R-value or RSI-value for insulation. A higher R-value means better thermal performance.

  • Individuals with an established audience for their work, including public figures, experts, journalists, and educators.

  • Low-latitude (23.4°S to 23.4°N) climate regions near the Equator characterized by year-round high temperatures and distinct wet and dry seasons.

  • United Nations

  • Self-propelled machine for transporting passengers or freight on roads.

  • A measure of one vehicle traveling a distance of one kilometer.

  • vehicle kilometer

  • volatile organic compound

  • Gases made of organic, carbon-based molecules that are readily released into the air from other solid or liquid materials. Some VOCs are greenhouse gases or can harm human health.

  • watt

  • A measure of power equal to one joule per second.

  • A subset of forest ecosystems that may have sparser canopy cover,  smaller-stature trees, and/or trees characterized by basal branching rather than a single main stem.

  • year