Geo-strategies to fight climate change

Carbon dioxide (CO₂) reached alarming levels in our atmosphere. A part of all CO₂ emitted comes from the natural degassing of the Earth's subsurface as a result of the rock cycle, which we refer to as geogenic CO₂. Monitoring phisico-chemical parameters in sites of natural CO₂ degassing, or seeping, gives us insight into the CO₂ geological cycle and helps us to develop and de-risk potential CO₂ storage solutions in the subsurface.

These natural CO₂ springs are common in the eastern part of Belgium, notably around the town of Spa. They are locally known as pouhons and are typically ferruginous, with a distinctive orange colour, and naturally bubbly (up to 4g/L dissolved CO₂). As a researcher in the Geo-energy group of the Geological Survey of Belgium, I have co-coordinated a monitoring campaign of groundwater springs along a river stream near Spa. The campaign has faced numerous difficulties due to continued dry periods and the COVID-19 pandemic, but preliminary results are encouraging and we keep seeking further funding to continue the work.

Read a summary of the preliminary monitoring results.

Project funded by the Geological Survey of Belgium (2019-2020).

Crushed basalt (called waste ‘quarry dust’) has the potential to reduce atmospheric CO₂ when applied to soils. It is in discussion that ERW could favour carbonate precipitation in the oceans because it consumes protons from soil acids, releases calcium and magnesium in soil solutions and runoff, and increases water pH. Basalt quarry dust could also act as a soil fertilizer (a source of phosphorus for example), enhancing organic carbon fixation within soils.

There are still a lot of unknowns preventing the upscaling and widespread utilisation of ERW. As a post-doctoral researcher in University College Dublin (Ireland), I was part of this pilot project on ERW to better understand the kinetics of local basalt ‘quarry dust’ weathering in field and laboratory experiments. This pilot study served as basis for further research on the theme in University College Dublin.

Project funded by the Geological Survey Ireland (2017-2018).