Here’s a problem I keep coming back to: a lot of the cations we think we’ve released by weathering may not be where we think they are.
In enhanced rock weathering, that question isn’t theoretical. When basalt weathers, it releases cations which either lead to alkalinity that moves through soil water, into drainage systems, and eventually toward the ocean or goes somewhere else. During weathering there are so many different reactions that make tracking exactly how much and where it ends up very difficult.
After working on this for several years and collecting data across multiple experiments, we’ve seen how sensitive the results are to assumptions, measurement approaches, and local conditions. In some cases, what looks like carbon removal in the data may reflect transport, transformation, or simply the way we account for it. The boundary between what is measured and what should be counted is still being worked out.
This is not a niche methodological detail. It’s one of the questions that determines whether ERW can deliver at the scale the field is aiming for.
At the Carbon Drawdown Symposium on 16 June, we’re going to look at this directly—based on five years of measurement data and some very interesting different projects that we are presenting publicly for the first time.
Free to attend, virtual. Registration link: https://events.carbon-drawdown.de/p/symposium