How to measure rock weathering carbon sequestration: Explainer Video

Carbon Dioxide Removal and Enhanced Rock Weathering

The Carbon Community is running one of the world's very first field trials on enhanced rock weathering in reforestation. Enhanced weathering relies on the reaction of carbon dioxide in the atmosphere with silicate minerals, including basalt which is being studied in this research.

In order to verify that the basalt is reacting with carbon dioxide, breaking down and creating the weathering products that ultimately store carbon for a long time in the ocean, Bonnie and her team are using multiple techniques to measure the same information:

- Cutting blocks of soil out of the ground and extracting all of the moisture that's retained in the soil in order to look for the weathering products in that moisture.  

- Using a lysimeter to pull moisture from the soil in the forest to see how weathering products accumulate in it.  

- Burying litter bags filled with a known quantity of basalt. These litter bags have a very, very fine mesh. Over time the bag is weighed to see how much of the basalt is actually dissolving,  weathering and capturing carbon dioxide.  

“We think this field trial is really special. It's not just because of the size and the replication, but also because of all the effort we're putting in to make really sure that we're measuring this carbon dioxide removal process as accurately as we can.”

Bonnie Waring, Senior Lecturer, Imperial College London