EGU23-13354, updated on 22 Apr 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Preliminary findings from comparison of in-situ measurements of enhanced weathering proxies with model predictions

Kirstine Skov, Tzara Bierowiec, Ifeoma Edeh, Mike Kelland, Amy Lewis, Melissa Murphy, Ryan Pape, Will Turner, Peter Wade, Jez Wardman, and Xinran Liu
Kirstine Skov et al.
  • UNDO Carbon Ltd., Science, Research and Innovation, United Kingdom

Enhanced weathering of silicate rock is a promising natural carbon dioxide removal technology, both due to its scalability and associated agronomical benefits. During silicate rock weathering, dissolved carbon dioxide in the form of carbonic acid, reacts with rock minerals to form stable soil pore water bicarbonate or soil calcium carbonate. The carbon dioxide removal potential of enhanced weathering has been successfully demonstrated in short-term lab and mesocosm studies. Due to the transient nature of bicarbonate in the aqueous soil solution, in-field quantification of the carbon dioxide sequestered is tedious, labour-intense and poorly scalable for the verification of carbon credits. Various methods have been suggested in order to quantify the amount of carbon dioxide sequestered through rock weathering. This quantification is essential for verification bodies to award carbon credits. Although various methods have been proposed to demonstrate that in-field weathering is occurring, there is still no consensus for a scalable, profitable solution. In recent years, an increasing number of field trials have seen the light of day. However, large uncertainties about in-field weathering rates and the influence of natural environmental variability, such as drought and vaying temperatures, still exist. 

In this study we focus on two proxies affected by the weathering process, namely pH and EC. We compare field measurements of pH and EC from both in-situ sensors and extracted soil pore water with model predictions from a 1D-reactive transport model. The data originates from an ongoing field trial on an acidic, clay rich soil used for grassland pasture in central Scotland. Such in-field proxy measurements may provide information to help boost confidence in model predictions.

How to cite: Skov, K., Bierowiec, T., Edeh, I., Kelland, M., Lewis, A., Murphy, M., Pape, R., Turner, W., Wade, P., Wardman, J., and Liu, X.: Preliminary findings from comparison of in-situ measurements of enhanced weathering proxies with model predictions, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13354,, 2023.