Acknowledgement: Encyclopedia Britannica
In January 2020, this blog ran a post about Direct Air Capture (DAC), a somewhat misleading term that came into use for processes designed to extract carbon dioxide directly from the atmosphere. Three years later, DAC is one of an array of technologies under the general banner of Carbon Dioxide Removal (CDR), which I gather has not yet been officially adopted by the UNFCCC despite IPCC estimates that CDR will be needed on a big scale to have a hope of reaching Paris Agreement targets.
So what has sodium bicarbonate to do with this? Well, the answer hinges on a point made in the 2020 post that atmospheric CO2 co-exists in dynamic equilibrium with oceanic CO2. Removing CO2 directly from the atmosphere will result in oceanic CO2 outgassing to restore equilibrium. In other words, DAC is insufficient in itself to achieve the desired drawdown. Ocean CDR needs to be brought into the equation. (more…)
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