We present insights we gained from CO₂ efflux, soil pCO₂ and soil water leachate alkalinity data of 400 greenhouse experiments for enhanced weathering (EW).

Why and how we built our army of autonomous CO₂ fluxmeters

Last week we have extended our greenhouse experiment with 78 new lysimeter experiments to now close to 400 experiments in total.

We document our latest pCO₂ sensor design and share a preview of our pCO₂ data while comparing these with the CDR estimates we recently derived from alkalinity.

Here is a look at Carbdown’s year 2023 with a collection of videos about our work!

We update our document from 3 weeks ago about estimating carbon dioxide removal (CDR) by enhanced rock weathering (ERW) using measurements of alkalinity in leachate waters.

How do we “transfer” weathering rates measured in our greenhouse to the outside world?

In this blogpost we explain how the carbon dioxide removal (CDR) effects of weathering rock can be estimated using alkalinity measurements and what early results we see in our greenhouse experiment.

In part one of our greenhouse data series we publish the biomass data from our greenhouse experiment (how much has biomass changed after adding rock dust to different soils?).

Why we use high frequency monitoring on a slow process and how we handle and analyze more than 4 million data points per day in real time

While we are preparing a first look at the weathering data we have also looked at how the ambient climate in the greenhouse has developed since January. Here is an overview of this data.

A photo diary of the things that happened in the greenhouse.

Drawing from our experience, we hereby propose the concept of “scopes” to simplify the process. This concept is also used in the Greenhouse Gas Protocol standard to categorize greenhouse gas emissions. We'll apply this same idea to ERW.

Our CEO held a conference session about our scientific work with measuring of enhanced rock weathering on croplands.

After more than two years of ERW experiments we still fail to measure carbon dioxide removal with traditional chemical analyses and electronic soil sensors. But when we started to monitor CO₂ concentrations in soil gas we found a signal immediately!

The building process of our XXL Lysimeter project in May 2022 and the monitoring of the first 3 months was closely documented in a Master Thesis.

A graph that shows the annual Carbon Cycle (carbon pools and carbon fluxes) for 1 m² of cropland including the Carbon Removal Effect of Enhanced Rock Weathering

How we built the Carbdown Greenhouse Experiment 2023, including the reasoning of the design, our shopping list and the building recipe.

This is how spreading 50.000 tons looks like! We have asked people from around the world that are doing enhanced weathering projects with basalt or other rocks to send us some photos and a short description of their work.

Our pilot project with 1217 tons of basalt demonstrates the full value chain for ERW at € 230 per ton of CO₂ (with € 100-150 in sight)