Enhanced rock weathering (ERW) is a low-cost and sustainable carbon sequestration solution based on accelerating rock natural weathering by grinding it into fine powder and spreading it over large land areas. Complimentary to carbon dioxide (CO2) emissions reduction, ERW offers a scalable way to remove atmospheric CO2 by facilitating its conversion into stable carbonate minerals for long timescales (thousands of years). Measuring ERW carbon sequestration means our Science Team embraces every detail.
To analyze and understand ERW, InPlanet stresses that #everydropmatters.
Time, money, land, water – what do these elements have in common? These are precious resources. In a scenario where every minute, cent, hectare, and drop needs to be well managed; things are not different when we are talking about soil pore water samples. Many regions around the world are already experiencing water scarcity due to climate change and pollution. For ERW projects, water is a critical component of the chemical reactions involved in rock weathering.
In our laboratory, we receive hundreds of liquid samples every week from all our experiments. Most of these liquids are leachates coming out of the soil pores after percolation triggered by rain events, bringing with them important information in small portions. This information relates to the process of ERW on a local scale, through which the complex reactions among soil, rock powder, water, and biological agents (such as microbes, plants, and animals) result in carbon dioxide removal (CDR).
Given the importance of fighting climate change, we need to make the best use of every single drop to measure the capacity and intensity of ERW for CDR in field settings located in Brazil. Under natural conditions as in research farms, these samples are completely dependent on rainfall – hence, the motto “every drop matters”. We want to emphasize that we value every bit of our samples and what they bring to the world.
The liquids sampled from soil pores in field experiments by InPlanet are analyzed chemically to determine the pH, electrical conductivity, ions such as calcium, magnesium, potassium and phosphate, and carbonate/bicarbonate. By integrating and modeling these data, we can better understand the progress of the chemical reactions between soil, rock powder, rain, and carbon dioxide.
It is therefore possible to assess the extent of CO2 uptake and efficiency of the ERW process as a CDR strategy. These data are the basis for our scientific robustness in measuring, reporting, and verifying the CDR through ERW. By measuring the concentration of these chemical elements in soil pore waters, we can estimate the extent of rock dissolution and carbonate mineral formation, which directly correlates with CO2 uptake. This helps validate the underlying mechanisms of ERW and ensures the accuracy of carbon sequestration estimates.
Overall, every drop matters when it comes to measuring ERW carbon sequestration in research projects. This means that every sample and every drop is valuable in achieving the ambitious goal of removing tons of CO2 from the atmosphere to mitigate climate change.
