Press Release: Scientific Non-Profits Release New Map & Data to Advance Key Ocean-Climate Research

New dataset will support assessments of ocean alkalinity enhancement — an approach to increasing ocean-based removal of carbon dioxide from the atmosphere

October 15, 2024 — Today [C]Worthy and CarbonPlan, two scientific non-profits, released the first ever interactive map describing where ocean alkalinity enhancement (OAE) can be done most efficiently around the world. OAE is a high potential marine carbon dioxide removal (mCDR) approach; it was identified as a research priority by the National Academies of Science, one of the world’s leading scientific institutions, and is currently receiving tens of millions of dollars of R&D funding from the U.S. Government.

While interest and funding for OAE research has been growing, a significant gap is understanding where deployments can be most effective at removing carbon dioxide from the atmosphere.  The new graphical interactive tool called the OAE Efficiency Map helps address this and other questions. In addition to the interactive tool, the team is releasing a technical article explaining the scientific methodology used to generate the map and possible applications for the dataset. [C]Worthy is also releasing the full dataset underlying the map and a scientific manuscript will soon be published in the journal Nature Climate Change.

These tools are being released on the heels of a series of historic investments and actions advancing mCDR, and OAE specifically. Last fall, the White House launched a Fast-Track Action Committee on mCDR, a major signal that the US government is prioritizing research in this field. The National Oceanic and Atmospheric Administration (NOAA) and the Department of Energy (DOE) have collectively granted more than $60 million to leading scientists in the US who are overseeing crucial research, from laboratory and mesocosm studies to responsible and safe field trials. [C]Worthy has received funding from both NOAA and DOE. 

The interactive map and the underlying data help scientists and practitioners explore how adding alkalinity to different regions of the ocean can lead to carbon dioxide removal from the atmosphere over time. The data show that alkalinity addition to the ocean at subpolar latitudes leads to rapid carbon dioxide uptake from the atmosphere, and over much of the low-latitude ocean, OAE can lead to efficient carbon removal, but achieving the full potential uptake can require 10 years or more following the alkalinity addition. High-latitude regions tend to be areas of low efficiency, particularly in winter, as the added alkalinity is rapidly removed from the surface ocean by ocean circulation and mixing. 

The dataset was produced using a state-of-the-art, scientific-grade ocean model developed at the U.S. National Science Foundation National Center for Atmospheric Research. This model is used to simulate the removal of carbon dioxide from the atmosphere resulting from the addition of alkalinity in different seasons and locations. Scientific evidence indicates that carbon removed from the atmosphere via ocean alkalinity addition will be durably stored in the ocean for thousands of years.

The interactive map allows the user to select an ocean region and then visualize how alkalinity deployed in that region will result in atmospheric carbon removal over time. This information shows where adding alkalinity to the ocean will result in real carbon removal on timescales of interest to climate change mitigation efforts. The map also allows users to investigate how alkalinity released in a single region will travel through the ocean — and the associated changes in pH and other properties stemming from this addition. Notably, the ocean flow rapidly disperses the added material, which means that broad changes in pH are very weak beyond the immediate site of addition — though locally, OAE can help mitigate ongoing ocean acidification.

[C]Worthy and CarbonPlan believe these tools will inform continued efforts to create scientifically rigorous standards and effective regulatory frameworks for ocean-based CDR. This represents an important step in understanding the carbon sequestration potential, which needs to be evaluated alongside potential environmental and social impacts. 

“This map and dataset illustrate some of the key controls on the efficiency of ocean alkalinity enhancement,” said Matt Long, CEO of [C]Worthy. “We think these tools make an important contribution to evaluating the promise of ocean alkalinity enhancement and advance efforts to quantify its effectiveness.”

"Developing effective climate solutions requires robust, transparent data," said Freya Chay, Carbon Removal Program Lead at CarbonPlan. "The tool is designed to equip scientists, policymakers, and the public with new insights, ensuring ongoing rigor in the exploration of ocean-based CDR approaches like OAE."

"This important work from [C]Worthy and CarbonPlan will help increase our understanding of the variables influencing OAE efficacy, and over time, this is exactly the type of analysis needed to inform where OAE could have the greatest climate benefit,” said Dr. Antonius Gagern, Executive Director of the Carbon to Sea Initiative, which helped to fund the interactive tool. “We’re excited about this work because it adds to a growing set of tools to help inform the evaluation and decision-making around ocean-climate solutions, including historic investments by the United States government – building on a call to action from the National Academies of Science.”

"We need more tools like this across the mCDR sector to help the field advance responsibly," said Dr. Kristin Kleisner, Associate Vice President for Oceans Science at the Environmental Defense Fund. "As scientists carefully determine whether and where OAE can be an effective part of the portfolio of mCDR approaches, the map and underlying data will enhance transparency and improve decision making."

“These new tools will help the research community to assess the efficiency and viability of OAE globally, and they will be strengthened over time," said Dr. Matthew Eisaman, Associate Professor at the Yale Center for Natural Carbon Capture. “As OAE research moves from the lab to mesocosm and field research, tools like these will help add rigor – and inform the practices and standards that practitioners use.”

“This new model-based tool is an excellent example of how we responsibly advance ocean-based climate solutions,” said Jaime Palter, Associate Professor at the University of Rhode Island’s Graduate School of Oceanography. “The tool will allow users – from curious members of the public to sophisticated researchers – to explore how OAE might work around the world, and this kind of transparency will help the field build trust. The next step will be additional modeling and research to help us better account for the scientific uncertainty inherent in modeling a nascent carbon dioxide removal approach like OAE.”

“These visualizations are an important contribution to the scientific community’s ongoing discussions about how alkalinity enhancement should occur going forward, as research progresses and technology improves,” said Jess Adkins, Caltech Professor of Geochemistry and Global Environmental Science. “These tools will be an asset for practitioners, regulators, and the public about this promising carbon dioxide removal approach.” 

Some key facts and takeaways from the dataset: 

• The ocean model used represents the three-dimensional circulation of the ocean and includes a biogeochemical model called MARBL. Since the physical circulation model is coarse resolution, its representation of the ocean flow is not perfect — but it does simulate broadly realistic circulation patterns, including surface currents, ocean overturning, and vertical mixing.

• To compute net CO₂ uptake induced by OAE, the dataset evaluated the time evolution of the simulated air-sea CO₂ flux relative to an identical baseline simulation with no OAE intervention.

• For many regions, a significant portion of the total carbon uptake happens more than 1000 kilometers away from the site of alkalinity addition. This emphasizes the importance of rigorous approaches to modeling to understand how carbon uptake mediated by OAE play out over spatial and temporal scales that are difficult to observe directly.

• The tool shows that a few regions stand out as having relatively high carbon removal over the course of a year or two post-alkalinity release. This includes subpolar regions in the North Atlantic, North Pacific, and Southern Ocean, as well as areas along the equator. 

• As time progresses past the first couple years, the amount of geographic variation in OAE efficiency begins to diminish. By year 15, much of the ocean begins to approach the thermodynamic maximum efficiency. An exception is the subtropical gyres and high-latitude regions, which even after 15 years have relatively low OAE efficiency.

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