CDR Verification Framework Documentation
Docs: Component
Base dispersal into ocean
Uncertainty
If alkalinity is added the ocean directly (e.g. via aqueous NaOH), the total alkalinity released it can be directly measured. Environmental conditions and alkalinity addition dynamics may result in different fractions of carbonate (CO₃⁻²) versus bicarbonate (HCO₃⁻). This fractionation impacts the total uptake of atmospheric CO₂. Overall CO₂ uptake efficiency can be estimated using seawater chemistry modeling software and the equation presented in Renforth & Henderson (2017). These estimates could also be validated by measurements of bicarbonate concentrations or total alkalinity in the water column. The conversion of alkalinity to CO₂ removal is estimated to be 70-95% on a mol to mol basis.
Applicable pathways
Pathway
VCL
Ocean Alkalinity Enhancement (Electrochemical)
3
Revision history

Apr 10 2023
Edited component text for clarity. Edited uncertainty range from Low-Medium to Low-Low to reflect more realistic uncertainties for model parameterization, and temperature and salinity variability.

Sep 19 2022
First release.
Base dispersal into ocean
Uncertainty
If alkalinity is added the ocean directly (e.g. via aqueous NaOH), the total alkalinity released it can be directly measured. Environmental conditions and alkalinity addition dynamics may result in different fractions of carbonate (CO₃⁻²) versus bicarbonate (HCO₃⁻). This fractionation impacts the total uptake of atmospheric CO₂. Overall CO₂ uptake efficiency can be estimated using seawater chemistry modeling software and the equation presented in Renforth & Henderson (2017). These estimates could also be validated by measurements of bicarbonate concentrations or total alkalinity in the water column. The conversion of alkalinity to CO₂ removal is estimated to be 70-95% on a mol to mol basis.
Revision history

Apr 10 2023
Edited component text for clarity. Edited uncertainty range from Low-Medium to Low-Low to reflect more realistic uncertainties for model parameterization, and temperature and salinity variability.

Sep 19 2022
First release.