Research suggests that storing liquefied carbon underground might increase the risk of earthquakes.
One of the ways that have been proposed for storing carbon out of the way and, hence, reducing emissions in the atmosphere, has been to liquefy the gas and place it in the earth. This seems a logical approach in that carbon returned to the ground has a positive impact on the global climate change challenge and can be kept there until some more positive use for it can be found.
However, there appears to be a problem that the process of putting the carbon in the ground might lead to increased risk of earthquakes (see this story for more details). It is difficult to understand the actual amount of the risk involved because so little carbon actually has been stored underground so far. In addition, the physics of seismic activity is really very complex and although scientists have a good idea of how it all works, the numerous variables involved make predicting actually what will happen and when particularly difficult.
The result is that data is only now being collected about the shifts in weight and mass under the surface of the earth and its impact on seismic activity. One comparable area of examination is in the so-called fracking, or hydraulic fracturing, which involves the explosive expulsion of hydrocarbons from inside the earth from mining processes. Fracking has become associated with one particular earthquake, measuring some 2.3 on the Richter Scale and occurring at England’s seaside resort of Blackpool. That magnitude of earthquake is not likely to cause too much damage in itself but the fracking processes have not been in operation for very long. The concern is whether longer term and more extensive processes might lead to much larger earthquakes.
Carbon storage is of course the opposite process to fracking, since the former involves forcing liquefied gas into the ground and the latter involves something similar to the reverse process. However, both involve making changes in mass and pressure underground at an enormously more rapid rate than is generally found in nature (i.e. away from volcanic activities). Carbon storage, under current technology, involves high pressure injection of material and this makes it a more risky process than others.
More research is clearly required into this area because projections of how climate change may be fought and emissions targets approached currently incorporate a significant storage component. If the technology turns out to be more expensive than had been anticipated or else it is impractical altogether, then this will represent an important new problem and the world and its people are at a point when new problems are not really needed.