The term “Enhanced Weathering” in the context of Greenhouse Gas Removal methodologies describes the application of rock powder to sequester CO2 by chemical weathering in terrestrial or aquatic systems. Besides the sequestration of CO2, and depending on the quality of the used rock, geogenic nutrients are released. Those can increase biomass or crop production of certain plants.
While the dissolution of minerals under laboratory conditions is well studied, mechanistic understanding of the processes involved in chemical weathering and subsequent release of nutrients under field conditions needs improvement. The addition of large amounts of rock powder to soils would alter element fluxes through the ecosystems and in dependence of amount influence soil hydrology.
This workshop addresses specific research questions to reasonably estimate dissolution rates, limiting processes, positive and negative side effects. Scientists from different disciplines (geologists, biologists, engineers, soil scientists) will address the topic from different angles.
The main questions are:
Is Enhanced Weathering feasible to sequester CO2 considering the chemical but also biological processes?
What rock sources are applicable?
- Are dunites applicable or are basalt, volcanic sediments, or even limestones also feasible?
Can we predict the rates of mineral dissolution?
- What do we need to know to model Enhanced Weathering, besides the already used processes and parameters in established models?
- What issues haven’t been identified yet, for example rate limiting steps?
- Could bioturbation be a relevant factor to be considered?
What are the consequences of reactive material in soils?
- How would pH distribution in soils change?
- Would the PCO2-distribution in soils be altered due effects on ecosystems?
- For which scenarios an increase in biomass or crop production are likely?
- Which contaminants might be released/accumulated depending on the choice of rock sources?
- What do we know about further specific side effects?
How would ecosystems react considering nutrient limitation of P, K or if beneficial nutrients like Si, Ca, Mg are added?
What would happen if the aquatic Si/N or Si/P ratios are altered?