Offshore underwater volcanos could be great locations for carbon capture and storage (CSS) projects, researchers have found. 

In order to analyse the possibilities of these sites, the research team looked at how much carbon could be stored in the Fontanelas volcano, located off the coast of Portugal, partially buried around 100 kilometres offshore from Lisbon.

Their findings showed that the extinct volcano could store as much as 1.2-8.6 gigatonnes of carbon dioxide, the equivalent of 24 to 125 years of the country’s industrial emissions. In contrast, 42.6 megatonnes (0.0426Gt) of carbon dioxide was removed from the atmosphere by international carbon capture and storage efforts in 2022, according to the Global CCS Institute.

Therefore, the new study presents offshore underwater volcanos as a promising direction for CSS efforts. 

“We know that most countries, including Portugal, are making efforts to decarbonise the economy and our human activities. This...