Underground storage of carbon dioxide may trigger earthquakes which could allow the gas to seep back into the atmosphere, rendering the emissions mitigation approach ineffective, warns Stanford geophysicist Mark Zoback.
Capture and storage of carbon dioxide underground has been seen by some as a potential means to slow rising greenhouse gas levels in the atmosphere. But now wars that excessive amounts of carbon dioxide is likely to give rise to moderate earthquakes. Though these earthquakes are unlikely to be of colossally disastrous nature, they could undermine the feasibility of these gas reservoirs.
Zoback says the volume of CO2 is too great to be stored in underground sites. For carbon dioxide sequestration to be effective, thousands of injection sites would be needed all over the world.
Due to tectonic faults, the possibility of potential earthquakes become realistic. Injecting massive amounts of carbon dioxide into the subsurface could activate faults and trigger tremors.
Zoback says he doesn’t oppose carbon dioxide sequestration but is cautioning about the dangers of the approach. Though large earthquakes can be easily avoided, the problem that arises is that seismic activity may create small pathways that would re-release the stored gas back into the atmosphere. This could make the entire project futile.
Zoback suggests a public education campaign to combat rising emissions and estimates that 3,400 projects may be needed by the mid century to slow greenhouse gas emissions. Currently, two sequestration projects are in progress in Norway and Algeria.
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