Underground CO2 storage safe, say scientists

Posted by Kate Taylor

Storing carbon dioxide underground poses little threat to health, scientists from the University of Edinburgh claim.

Carbon capture and storage schemes have been widely touted as a possible solution to manmade climate change.

CO2 is collected at a power station or industrial site, liquefied, and then 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.

However these schemes have drawn fire from campaigners, particularly in Canada and northern Europe, who believe there's a risk of leaks, and that these could be hazardous to human health.
 
But, according to the Edinburgh team, the risk of death from poisoning as a result of exposure to CO2 leaks from underground rocks is about one in 100 million.

They came up with this figure by studying historical data on deaths from CO2 poisoning in Italy.Sicily, where volcanic activity causes the gas to seep naturally from the ground. These CO2 seeps are natural, and are often neither fenced off or even signposted

And they found that the number of recorded deaths was very low - and say that engineered gas storage underground could be even safer, as it would be planned and monitored.

"Such technologies will play an important role over the next 50 years, as a bridge to the development of clean energy," they say.