Through small reactions such as rain falling on rocks, tiny amounts of carbon dioxide are being removed naturally. Geologists and scientists have discovered this as a method of carbon sequestration, and they are looking into the possibilities of implementing this through large-scale operations. While this is a method to be considered, there are questions of whether this is a realistic option.
Rainwater has a history of making impacts on the geographical make-up of our planet and one of these processes include weathering. There are different types of weathering: biological, chemical, and physical. Chemical weathering describes how chemicals in rainwater react with the minerals in a rock, and this also describes how carbon dioxide reacts with rainwater. Once CO2 dissolves in rainwater, it makes it acidic. From there, the acidic rainwater encounters the minerals in rocks and weathers it away.
From a geologist’s point of view, the roles of different types of rocks come into play in trapping CO2. Pores include the makeup of porous rocks, and these are used to trap water. The empty space can trap substances without leaking out. From this, many scientists are considering using porous rocks to trap carbon dioxide and using a layer of impermeable rocks to keep the substances from leaving. Impermeable rocks are self-explanatory as they do not allow a substance to escape from it. Some examples of these include shales and unfractured igneous and metamorphic rocks.
Combining this proposed plan with the properties of chemical weathering, it seems possible that carbon dioxide can be sequestered naturally. However, that is not the case. This natural process would need to be altered along with technological change because of the lack of land and space. While there are many geological locations that are mountainous, there is not enough to remove the amount of CO2 we would need it to in order to keep up with how much we are emitting. There are also propositions through artificial measures such as crushing the rocks so that carbon dioxide wouldn’t have to go through all layers underground. They plan to spread the crushed rocks over large areas, whether land or ocean, to increase the surface area of the reactions.
While this may seem like a possible solution, there are always trade-offs in environmental solutions that need to be considered. In this case, one aspect is the cost and energy. The amount of money and labor it would take to transport the rocks across vast areas of land might compete with the needed labor for other large industries. In addition, the amount of land it would take to spread the rocks throughout the planet wouldn’t leave enough room for other fields such as food production and forests. Therefore, there are certain trade-offs to this method, but it is one way that could help sequester carbon.
Hi Kimberly! I remember reading and learning about some of this in my Environmental Science class in high school, so it was interesting to revisit the subject with your added details and this potential solution of using both porous and impermeable rocks to prevent too much carbon dioxide from being in the atmosphere. It’s cool to think about ways of regulating the Earth using the Earth itself. It almost feels like we have disrupted natural processes and are now trying everything to recover those systems so as to undo the damage we have done. It’s interesting that you have a whole blog dedicated to carbon sequestration, it probably allows you to go into extreme detail into the different aspects of the subject. Good post!