Making mistakes in estimating the CO2 sequestration potential of UK croplands with enhanced weathering

Abstract

Determining the potential of UK croplands to sequester CO2 via enhanced rock weathering (ERW) is important for farmers, government, policymakers, NGOs, and other stakeholders aiming to deliver UK net-zero by 2050. This goal requires drawing on a range of approaches, from process modelling to field trials, to arrive at realistic quantification. Buckingham et al. (2022) report results from an alkaline soil ‘tubes on a roof’ ERW experiment with coarse basalt dust attempting to address this aim. We highlight unfortunate fundamental errors in the execution of the experiment, reporting and interpretation of the results. These ERW results for a chalk soil, under dry conditions, are then extrapolated erroneously across millions of hectares of UK croplands to misrepresent UK cropland CO2 removal potential by ERW.