Carbon dioxide storage has long been discussed as a way of offsetting emissions from construction companies and other polluters. However it has also faced severe criticism as being a way for rich firms to essentially ‘pay to pollute’. Now a team of scientists from Stanford University say that there could be an even more serious side-effect – earthquakes.
According to a paper that has been published in the Proceedings of the National Academy of Sciences, earthquakes could severely damage underground storage facilities causing the harmful gas to be released anyway. While they do not confirm that Carbon Capture and Storage (CCS) would directly cause seismic damage, they do say that “it is likely that the earthquakes would be severe enough to jeopardize the ability to store the gas underground over the long term”.
Considering the entire process sees CO2 captured and injected underground at high pressure, the chance of some sort of build-up is to be expected. The Stanford team note that the slightest change in underground pressure can cause small earthquakes and CCS sites could be damaged as a result.
Speaking to the LA Times, Mark Zoback, a geophysicist at Stanford University and an author of the commentary said: “If even a small leak develops, you’ve not succeeded in doing anything for the environment.”
Carbon Capture and Storage is not the only recent energy development to draw criticism. Hydraulic fracturing or fracking which sees chemicals blasted into rock formations to release natural gas has drawn controversy. While the National Research Council has released a report saying that fracking carries a “low risk of such earthquakes”, they have said that CCS has the “potential for inducing larger seismic events.”
The obvious solution is to find a storage area that is not in a seismically active area, but the Stanford Team say that such sites are likely to be limited and hard to find as only the underground dynamics that would lead to large earthquakes are easily and cheaply detectable. There would always be the chance of a smaller earthquake releasing the gas.
“In many cases, you’ll get small to medium size earthquakes, and man, that’s the end,” Zoback said. “And if it is in a populated area, there is going to be a ton of concern about the leak, whether it’s safe to be there. So there’s this very strong downside for what is almost an inevitable event. Do we really want to take that risk with our time and money?”
Considering over 3,500 CCS sites would have to be constructed in order to make a dent in the US’s emissions (and cost trillions of dollars), it makes you wonder whether it’s really worth it.
via LA Times