Ocean Alkalinity Enhancement
The ocean is the world's largest active carbon sink, absorbing approximately 30% of annual human CO₂ emissions. Ocean Alkalinity Enhancement accelerates this natural process by adding alkalinity to seawater, increasing its capacity to absorb and permanently store atmospheric CO₂ as dissolved bicarbonate - without land constraints.
Submit OAE Project View methodology docs →How this pathway works
The ocean absorbs CO₂ through two mechanisms: the physical dissolution of CO₂ in seawater, and the biological pump (phytoplankton photosynthesis and sinking). Ocean alkalinity - the ocean's capacity to neutralise acid and absorb CO₂ - is a key determinant of how much CO₂ the ocean can hold.
Ocean Alkalinity Enhancement (OAE) adds alkalinity to seawater (typically via dissolved minerals or electrochemical processes) to increase this capacity. The added alkalinity reacts with dissolved CO₂ to form bicarbonate ions - a stable, permanent form of carbon storage that cycles through the ocean on timescales of hundreds of thousands of years.
OAE is a frontier pathway with enormous theoretical scale potential - the ocean is vast and alkalinity addition is not land-constrained. However, the measurement science remains challenging: attributing observed alkalinity and carbon changes to OAE interventions requires sophisticated geochemical monitoring and modelling to distinguish OAE signal from natural ocean variability.
Teravent applies conservative crediting with mandatory marine ecosystem monitoring protocols. We work directly with leading OAE research institutions to ensure methodology keeps pace with rapidly evolving field science. All OAE credits issued under provisional methodology are clearly labelled, with methodology subject to annual review.
Project types accepted
The following variants of the Ocean Alkalinity pathway are currently eligible for registration in the Teravent Registry.
Measurement, reporting
& verification
Teravent's Science Advisory Board assesses each pathway against four MRV dimensions. These scores reflect the current state of measurement science and are updated as methodology evolves.
OAE quantification relies on alkalinity and dissolved inorganic carbon (DIC) measurements across a monitoring grid. Attribution to OAE interventions requires careful comparison with control sites and natural variability baselines. Teravent MRP-04 governs sensor calibration, sampling frequency, and quality control for marine monitoring. Ecosystem impact (pH, aragonite saturation) is mandatory monitoring.
Key registration criteria
Projects must meet all of the following minimum requirements to be considered for registration under the Ocean Alkalinity pathway. Additional requirements may apply depending on project size, geography, and specific methodology version.
Sustainable Development
Goal alignment
All Teravent-registered Ocean Alkalinity projects must complete an SDG impact assessment at registration and at each verification period. 3 SDGs are tracked for this pathway.
Focus region: Pacific Ocean, Indian Ocean, Atlantic coastal - where co-benefits for communities and ecosystems are most significant and credit demand most transformational.
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