What's happening with ocean alkalinity enhancement?
OAE moving from the lab to the ocean with new research guidelines, government funding, and business startups
Ocean alkalinity enhancement (OAE) is the least developed of the geologic methods of carbon dioxide removal (CDR), having been tested only in computer models and small-scale experiments in the lab and ocean.
Other geologic methods of CDR such as ERW and DACPS have either been implemented at large scale or are on the verge of doing so. But OAE remains in only the experimental stage, having not yet been tested at a large scale in the ocean.
Big questions remain about how much CO2 OAE can remove from the atmosphere and how spreading large amounts of rock dust in the ocean will impact marine life.
Progress is being made toward answering those big questions, however. Recently, technical guidelines were published for how to effectively conduct research on OAE. And, new government funding in the U.S. for developing verifying carbon removal methods will add further incentive to OAE development. Also, new businesses are being created that are testing the waters of OAE by proposing pilot projects at several locations in the ocean.
These new developments in OAE are located mainly in Europe, North America, and Australia, with little attention paid to OAE in Africa and Asia as found in a brief online search conducted by geoCDR News.
Best practices for conducting OAE research
In an effort to standardize methods of researching OAE, a worldwide group of academic researchers published a 223-page document in 2023 that lays out suggested guidelines for effectively conducting research on OAE.
The 13-chapter document recommends quality standards to be met when conducting experiments or trials in the ocean and modeling OAE impacts to the ocean. Guidance is provided on and environmental justice.
The document makes several key observations, including:
- OAE shows promise as a potential CDR solution.
- Impacts to marine life from OAE are poorly understood and confirmatory testing should be completed before OAE activity moves from the lab to the ocean.
- Domestic legislation will be required to regulate research in the ocean.
- OAE accomplishes CDR when the atmosphere equilibrates with the ocean surface via air–sea CO2 exchange.
- Data from ocean water samples or in-ocean sensors may not adequately verify OAE carbon removal amounts. Ocean turbulence widely disperses the bicarbonate (alkalinity) formed by addition of rock dust to the ocean, rendering it difficult to detect the newly formed bicarbonate against the background of pre-existing bicarbonate in the ocean. Consequently, computational modeling will be necessary for verifying carbon removal amounts.
Recent government funding
OAE has not yet been significantly tested in the ocean. Three big questions about OAE remain:
- Does it work — does OAE remove CO2 from the atmosphere?
- How do you measure and verify the amount of CO2 removed by an OAE operation?
- What impact does OAE have on marine organisms?
In 2023 U.S. government agencies awarded about $55 million of grants to research projects allocated to those questions as follows:
- Efficacy of OAE. Total grants: $8,608,550
- Verification of carbon removed by OAE. Total grants: $39,509,290
- Ecological impacts of OAE. Total grants: $6,509,365
Philanthropic organizations contributed to a few of the grants. Most of the grants were from the U.S. Department of Energy (DOE) and the National Oceanic and Atmospheric Administration (NOAA). The grant announcements included additional grants for CDR methods other than OAE thus totaling more than $56 million. Grant recipients were universities, ocean research institutions, national labs, and a few businesses. The following three tables summarize the research projects.
Some of the projects overlap more than one of the three OAE questions (for example a project may involve both carbon removal efficacy and ecological impacts).
| Grant recipient (location) | Project | Grant amount (grantor) |
|---|---|---|
| Oregon State University | Electrolysis-driven weathering of basic minerals for long-term ocean buffering and CO2 reduction | $2,000,000 (DOE) |
| University of Hawaii | Assessing efficacy of electrochemical ocean alkalinity enhancement at an existing outfall using tracer release experiments and oceanographic models | $1,915,600 (NOAA, ClimateWorks Foundation) |
| U.S. Geological Survey | Tidal wetlands as a low pH environment for accelerated and scalable olivine dissolution | $1,895,531 (NOAA) |
| University of Rhode Island | Study impacts of coastal liming on ocean alkalinity enhancement, CDR, and ecosystem. | $1,538,452 (NOAA) |
| Northeastern University and NOAA GFD Lab | Developing a coupled benthic-pelagic biogeochemical model to evaluate the effectiveness of marine CDR interventions | $1,258,967 (NOAA) |
The bulk of the grants went to verification projects aimed at developing new methods for determining the amount of CO2 removed from the atmosphere by OAE methods; for example, measurement (sensors and sampling) technology, and computer modelling. One goal of the verification projects is to reduce or eliminate uncertainties that limit carbon credit quality. Accurate verification of carbon removal amounts will be necessary if the OAE industry will be funded by the sale of carbon credits.
Verification of carbon removal amounts in ocean waters is difficult due to water turbulence. Adding rock dust to ocean water in an OAE operation produces bicarbonate which increases the alkalinity of the water, increasing the water's uptake of CO2 from the atmosphere. Bicarbonate produced by adding rock dust to the ocean gets widely dispersed by turbulence which makes the bicarbonate undetectable against the background of abundant bicarbonate already in the ocean. Verification methods include sensors which directly measure alkalinity of the water (more bicarbonate equals more alkalinity) and water samples (which can be analyzed for bicarbonate and alkalinity in a laboratory). Computer modelling is also an important method of verification.
| Grant recipient (location) | Project | Grant amount (grantor) |
|---|---|---|
| University of Colorado (Boulder, CO) | System of optical underwater sensors utilizing broad-band lasers to sense and measure dissolved carbon compounds. | $5,904,233 (DOE) |
| Woods Hole Oceanographic Institution (Woods Hole, MA) | Natural thorium decay sensor that would attach to gliders, autonomous vehicles, and profiling floats to quantify the flow rates of particulate organic carbon to the deep ocean for marine carbon dioxide removal. | $4,802,245 (DOE) |
| GE Research (Niskayuna, NY) | Fiber optic sensor cable that would span multiple kilometers of ocean volume and measure chemical ocean carbon parameters [tooltip of examples of parameters: pH, total alkalinity, dissolved inorganic carbon, dissolved oxygen, conductivity, salinity] over large areas when towed from marine vessels. | $4,274,658 (DOE) |
| [C]Worthy (Boulder, CO) | Community framework for model building and data assimilation that would provide the structure and processes necessary to incorporate observations, manage model complexity, and meet the needs for accurate carbon accounting for carbon dioxide removal from the atmosphere. | $3,884,825 (DOE) |
| Woods Hole Oceanographic Institution (Woods Hole, MA) | System-on-a-chip for ocean carbon flow rate monitoring that would integrate the capabilities of several existing commercial sensors into a single miniature sensor chip, lightening the power requirements on ocean gliders and floats and significantly reducing costs. | $3,738,960 (DOE) |
| >atdepth MRV (Cambridge, MA) | Ocean modeling system that utilizes graphical processing units, dramatically improving simulation modeling speed compared with traditional approaches that use central processing units. | $2,524,964 (DOE) |
| Bigelow Laboratory for Oceanic Sciences (East Boothbay, ME) | Biogeochemical computer model that improves estimates of how the vast population of ocean zooplankton—tiny marine animals move and lock away carbon in the deep ocean. | $2,279,867 (DOE) |
| University of Pittsburgh (Pittsburgh, PA) | Buoy-based optical fiber sensors for measuring pH and carbon dioxide in seawater from the ocean’s surface to the seafloor. | $2,274,859 (DOE) |
| Pacific Northwest National Laboratory (Seattle, WA) | Model and chamber (mesocosm) experiments to evaluate the effectiveness and impact of the marine carbon dioxide removal technique ocean alkalinity enhancement throughout major coastal areas in the United States. | $2,080,715 (DOE) |
| University of Texas at Austin (Austin, TX) | Acoustic sensor network to quantify ecosystem activity and how effectively carbon is stored in shallow seagrass beds, an important sink in the coastal blue carbon cycle. | $2,034,903 (DOE) |
| University of Utah (Salt Lake City, UT) | Micro-optical, micro-electronic seafloor probe that would extend the longevity and persistence of current-day seafloor carbon storage measurement tools. | $2,004,554 (DOE) |
| University of Maryland Center for Environmental Science | Quantifying the Efficacy of Wastewater Alkalinity Enhancement on mCDR and Acidification Mitigation in a Large Estuary | $1,864,561 (NOAA) |
| University of Washington/CICOES | Biotic calcification impacts on marine carbon dioxide removal additionality | $1,250,482 (NOAA) |
| Columbia University | Data requirements for quantifying natural variability and the background ocean carbon sink in mCDR models | $589,464 (National Science Foundation, NOAA) |
| Grant recipient(location) | Project | Grant amount (grantor) |
|---|---|---|
| University of Hawaii, Manoa | Assessing the effects and risks of ocean alkalinity enhancement on the physiology, functionality, calcification, and mineralogy of corals and crustose coralline algae in the Pacific | $1,999,835 (DOE) |
| Woods Hole Oceanographic Institution | Assessing Carbon dioxide removal and ecosystem response for an ocean alkalinity enhancement field trial | $1,877,644 (NOAA) |
| Woods Hole Oceanographic Institution | Assessing the laboratory and field responses of diatoms and coccolithophores to ocean alkalinity enhancement | $1,026,045 (NOAA) |
| Scripps Institution of Oceanography | Assessing chemical and biological implications of alkalinity enhancement using carbonate salts obtained from captured CO2 to mitigate negative effects of ocean acidification and enable marine-based CDR | $995,891 (NOAA) |
| Vassar College | Determining the influence of ocean alkalinity enhancement on foraminifera calcification, distribution, and CaCO3 production | $510,359 (NOAA) |
| Responsible Offshore Development Alliance | Engaging U.S. Commercial Fishing Community to Develop Recommendations for Fishery-Sensitive mCDR Governance, Collaborative Research and Monitoring, and Outreach to Fishing Communities | $99,591 (Office of Naval Research, ClimateWorks Foundation) |
Recent Business Start-ups Focused on Geologic Methods of OAE
A handful of businesses have formed — both for profit and nonprofit — aimed at commercializing OAE using geologic methods. Their focus is mainly on developing their own small-scale OAE experiments or trials and ocean carbon measurement methods.
Start-ups include those summarized below.
| Company (location) | Company form | Funding source | OAE project types | Project locations |
|---|---|---|---|---|
| CarbonPlan (California, USA) | Nonprofit | Donations and grants | MRV software tools for valuing carbon credits and offsets. | In-house |
| Limenet (Lecco, Italy) | Investors,donations, carbon credit sales | Reacting slaked lime and CO2 to discharge bicarbonate to ocean. | La Spezia, IT (trial); Sicily (pilot) | |
| Planetary Technology Inc (Canada, UK and USA) | Privately-held for profit | Investors, grants, carbon credit sales | Spreading brucite, slaked lime, other alkaline materials in ocean | Various in Canada and U.S. |
| Project Vesta, PBC (California, USA) | Grants, donations, carbon credit sales (blog 11/4/21) | Spreading olivine sand in coastal areas (pilot projects) | Long Island, NY, USA; North Carolina, USA; Dominican Republic; | |
| Vycarb Inc. (New York, USA) | Corporation | Investors | Real-time water chemistry measuring device and an alkalinity dosing device. | Northeast U.S. coast |