Capturing CO2 from power stations and storing it deep underground carries no significant threat to human health, a study has shown.
Researchers found that the risk of death from poisoning as a result of exposure to CO2 leaks from underground rocks is about one in 100 million.
Scientists from Edinburgh University studied historical data on deaths from CO2 poisoning in Italy and Sicily, where the gas seeps naturally from the ground because of volcanic activity.
They found that the number of recorded deaths was very low and said that engineered gas storage underground could be even safer, as it will be planned and monitored.
According to the university, recent CCS projects in northern Europe and Canada have been criticised by residents over health concerns arising from potential leakage.
Carbon capture and storage enables collection of CO2 before it can escape into the atmosphere. The technology involves the collection of CO2 at a power station or industrial site. The gas is liquefied and piped to the storage site, where it is injected deep below ground.
The gas is stored in microscopic rock pores and eventually dissolves in underground water. Storage sites will have several barriers between the store and the surface.
Jennifer Roberts from Edinburgh University’s School of Geosciences, who undertook the work, said: ‘These Italian CO2 seeps are natural, often neither sign-posted nor fenced off, and yet there have been remarkably few accidents.’
Prof Stuart Haszeldine of Edinburgh University’s School of Geosciences, who led the study, added: ‘Our findings show that storing CO2 underground is safe and should allay any concerns that the technology poses a significant threat to health.’