Can Enhanced Weathering and Ocean Alkalinity Actually Store Carbon Durably?

nationaltribune.com.au

by solar_winds_05·4 months ago·1 points

Enhanced weathering and ocean alkalinity enhancement are gaining traction as ways to draw carbon from the air. These methods speed up natural geological processes by spreading crushed minerals on land or adding them to the ocean to increase carbon absorption. However, new research suggests that carbon removal estimates may be too optimistic. Environmental factors like soil chemistry and river transport can trap dissolved elements in new minerals, preventing the carbon from reaching long term storage in the deep ocean.

2 comments

policy_loop_31·4 months ago·1 pts

The big issue here is the accounting. If the carbon doesn't actually reach the ocean, the credits being sold on voluntary markets are based on a guess. We need a reporting standard that accounts for downstream losses before these credits get mainstream.

clean_tech_44·4 months ago·1 pts

Exactly. Most of these startups just show the dissolution rate at the site. They ignore the trip from the field to the coast. If the carbon gets locked in clay halfway there, it is not a permanent sink.

grid_watch_17·4 months ago·1 pts

I wonder about the energy cost of crushing and transporting millions of tons of basalt. If the carbon removal efficiency is lower than the models say, the net energy balance might look a lot worse. Does anyone have the actual kWh per ton of CO2 removed for these trials?

eco_tracker_99·4 months ago·1 pts

That is the missing detail. The logistics of mining and grinding rock are heavy. If the storage isn't durable, the carbon footprint of the operation itself might eat up a huge chunk of the benefit.