At last week’s ClimateTech Coffee 🚲 Bryan White and I were joined by Kimberly Gilbert, PhD to hear about her work on Carbon Neutralization and Ocean Storage (CNOS) through her company pHathom. Here’s a recap:
The ocean naturally absorbs CO2 over time, but we’ve added so much that the ocean has become increasingly acidic. Ocean pH has dropped from 8.2 to 8.1 globally over the last hundred years, and as pH drops it becomes harder for coral-based organisms to form shells.
To combat this, Ocean Alkalinity Enhancement (OAE) is an intervention that both reverses ocean acidification and removes CO2 from the atmosphere.
Challenges with traditional OAE:
- When you add the alkalinity into the ocean, it spreads out. It’s hard to measure the change in pH.
- You don’t know exactly when the extra CO2 will be absorbed. Modeling and measurement companies are trying to help with this problem.
Advantages of CNOS:
- Co2 is captured directly at a coastal power plant or refinery, and then the concentrated Co2 is pumped into water that has limestone (and/or other alkaline materials) in it.
- This means the Co2 is dissolved onsite and the pH can be equilibrated onsite, which makes accurate measurement more feasible.
Factors that affect progress:
- We’ll start seeing more companies enter in this space as the chemistry and its impacts are better understood and seen as safe
- Local and national permitting are a huge bottleneck
- On the international permitting level, the London Protocol has a blanket ban on ocean geoengineering for anything except for research. There were good reasons for doing that, but it’s unclear who decides when that can change and the circumstances under which the ban is lifted. (Note: pHathom is not doing geoengineering; it’s doing water treatment on-site and releasing it back as ocean water)
Open questions for the category/technology:
- Can they come up with enough low-cost alkalinity sources, and get them in a way that doesn’t cause additional environmental damage or Co2 emissions?
- This approach will require pumping a lot of water. How much will that cost and how can the cost be driven down?
- Putting 100 plants’ worth of bicarbonate into the ocean is likely fine for ocean health relative to the climate benefit, but what is the point where the tradeoffs cross over?
Some groups doing good work in this space:
[C]Worthy
Carbon to Sea Initiative
University Research: UC Santa Barbara, University of Tasmania, GEOMAR, Dalhousie University, Scripps
Join us for the next one in May! Details coming soon, and you can get updates by subscribing to the series page here: https://lnkd.in/g7DTGm2V
