The Carbon Drawdown Initiative announced that it has come up with a way to slash the time conventionally required to test the CO2 removal effectiveness of enhanced rock weathering (ERW) from more than six months down to 48 hours.
This breakthrough could save time and effort for ERW project developers by letting them know early on if the solution they are working on is indeed making a carbon removal impact.
While ERW can be a powerful approach for tackling atmospheric CO2 emissions, finding the right match between the soil composition and an appropriate and effective rock material is a process that takes a long time, where the performance metric tracked is the increase in alkalinity in water draining from the soil.
In 2023-2024, the Carbon Drawdown Initiative performed a greenhouse ERW experiment with 400 pots, where it took between 200 and 250 days to be able to identify which of the deployed soil-rock combinations was in fact working.
The team behind the experiment points out that in real-world field trials, these evaluations take even longer.
To help speed up this process, the Carbon Drawdown Initiative came up with a new method that reduces the time for testing the effectiveness down to only 48 hours.
This advancement was unlocked by a process in which the team combined 30 grams of rock together with 80 grams of soil and 150 grams of distilled water in an Erlenmeyer flask that was placed on a laboratory shaker for 48 hours.
During the test, the team measured the electrical conductivity, which they deemed a reliable proxy for the alkalinity changes that signal carbon removal activity.
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For three weeks, the researchers recreated 30 of the same soil-rock combinations they had used in their 2023-2024 experiment, observing that the short-term electrical conductivity results closely matched the long-term alkalinity ones.
The Carbon Drawdown team shares that they are still not sure what exactly causes this effect, and they will work on determining the continuous validity of this testing process by evaluating the carbon removal effect in more soil-carbon combinations.
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