Can Enhanced Rock Weathering Provide Durable Carbon Removal?

theconversation.com

by policy_loop_31·4 months ago·1 points

Enhanced weathering and ocean alkalinity enhancement aim to speed up natural geological processes to capture atmospheric CO2. While these methods are attracting significant investment from tech giants, new research suggests that carbon storage may not be as durable as initial models predict. Environmental factors like soil chemistry and river transport can cause captured carbon to be released or trapped in new minerals before it reaches long-term ocean storage. This creates a gap between headline carbon removal estimates and the actual amount of CO2 permanently removed from the atmosphere.

3 comments

policy_loop_31·4 months ago·1 pts

The biggest issue here is the accounting. If we are selling carbon credits based on dissolution rates at the application site but the carbon doesn't actually reach the ocean, the credits are essentially fake. We need a reporting standard that tracks the carbon all the way to the sink.

grid_watch_17·4 months ago·1 pts

Agreed. Also, nobody mentions the energy cost of crushing those rocks into fine powder. If the energy for the grinders comes from a dirty grid, you are eating into your net removals before you even spread the minerals.

clean_tech_44·4 months ago·1 pts

Interesting read. It basically says we might be moving carbon around rather than removing it. The part about interfering with natural weathering pathways is a red flag for anyone looking at additionality.

eco_tracker_99·4 months ago·1 pts

Exactly. If the tech just replaces a natural process that was already happening, the net benefit to the atmosphere is zero. The industry needs to prove the additional removal, not just the process speed.

retrofit_lens_44·4 months ago·1 pts

I wonder about the logistics of this at scale. Spreading crushed rock over millions of acres of farmland requires a massive amount of trucking and labor. The operational cost and emissions from the fleet could be huge.