Positives for mCDR in the Ocean Environment
Ocean-Based Carbon Dioxide Removal © 2023 by Ocean Visions is licensed under CC BY-NC-ND 4.0.
mCDR focuses on enhancing the ocean’s natural ability to store CO2. Research suggests that marine carbon dioxide removal can be ‘permanent’ (in that CO2 removed does not return to the atmosphere for centuries or much longer), but more work needs to be done to confirm effectiveness and ensure no harmful ecological effects.
Carbon dioxide removal from the atmosphere: defined
Carbon Dioxide Removal (CDR) refers to natural and technological techniques for directly removing carbon dioxide (CO2) from the atmosphere to combat climate change. Natural mechanisms for removing carbon dioxide from the atmosphere have existed since before mankind–trees absorb CO2 directly from the air, and the ocean naturally sequesters about 10 Gt of CO2 annually, roughly 25% of the 40 Gt emitted globally each year.
However, this is not enough to prevent the ongoing buildup of CO2 in the atmosphere in even the most optimistic emission reduction scenarios. The IPCC (the Intergovernmental Panel on Climate Change, the leading global climate collaboration of governments and scientists) has stated unequivocally that active removal of CO2 from the atmosphere will be necessary to keep global temperature increases below 2°C. This is not an alternative to reducing emissions–it’s an essential complement.
mCDR techniques enhance ocean’s ability to store CO2 in various ways
Some approaches utilize natural mechanisms–for example, Ocean Alkalinity Enhancement (OAE) involves adding alkaline material to the ocean, where it reacts with CO2 and forms stable compounds (specifically carbonate ions) that can remain in the ocean for centuries. This already happens naturally through coastal erosion.
Another extension of nature’s existing mechanisms is cultivation of kelp or algae which can then be sunk to the bottom of the ocean (kelp / algae used for products or food would not ‘remove’ the carbon). Other approaches are more technological–for example, Direct Ocean Capture (DOC) directly removes CO2 from seawater (often outflows from existing industrial operations). Taken together, modeling suggests that mCDR could scale to at least 1 Gt per year (e.g., see https://zenodo.org/records/14692650) and potentially much more (e.g. see https://eepower.com/tech-insights/comparing-marine-energy-powered-carbon-removal-methods/).
And one of the exciting characteristics of mCDR is the potential for ‘co-benefits’–in addition to removing CO2 and helping to mitigate climate change, mCDR can provide useful products, and may even help to reverse ocean acidification and ocean warming.
mCDR is in its infancy
However, the mCDR industry is in its infancy. Research suggests that mCDR can be ‘permanent’ (in that CO2 removed does not return to the atmosphere for centuries or much longer), but more work needs to be done to confirm effectiveness and ensure there are no harmful ecological effects.
The ocean is a shared resource with many diverse stakeholders, including its non-human residents, and its use spans many industries, including transportation, fishing / aquaculture, recreation, energy and marine conservation. Ensuring there are no harmful impacts on any of these groups, and convincing stakeholders, will take time and effort. New technologies for monitoring safety and effectiveness are still being developed, such as advanced 4D computational models of ocean physics and biogeochemistry, as well as new sensors for detecting changes in key parameters at the necessary speed and resolution.
As this ocean-based effort gains traction, the SF Bay Area has a wonderful opportunity to become a key hub for an emerging industry. mCDR can benefit from the capital and scaling knowhow the Bay Area has brought to many new technology-based industries. With direct access to the Pacific Ocean, and several world class oceanographic research groups, the Bay Area is a prime candidate for an mCDR field operations center. Several mCDR companies, notably Ebb Carbon, Project Vesta and Subtidal, as well as leading ocean data/tech companies like Sofar Ocean, are already taking advantage of the Bay Area’s unique benefits.
Questions remain, but mCDR has the potential to benefit the San Francisco Bay Area, the oceans, and the world as a whole.
author: jonathan kirk
Jonathan is co-founder of Submarine, an ocean modeling company working to limit global warming. For SF Blue Tech, Jonathan will explain the science and technology behind marine CDR. He will highlight industry vendors, the regulatory landscape and ways that AI and modern software can support a revolution in ocean modeling.