THE potential of a proposed carbon dioxide storage site in the Moray Firth has been significantly overstated, scientists claim.

The Captain Sandstone site has been suggested as a location for a carbon capture and storage (CCS) facility, with harmful emissions taken from the atmosphere and locked into underwater rock formations.

However, scientists from Heriot-Watt University in Edinburgh say the site is “wrong” due to the uplift and changes in the subsurface that occurred 55 million years ago.

Chief scientist Professor John Underhill said: “Many geoscientists, including myself, believe geologic storage of CO2 offers a significant opportunity to arrest greenhouse gas emissions into the atmosphere and reduce our carbon footprint.

“However, it is essential that the right site is chosen to prove the potential of this technique and demonstrate that CO2 can be safely stored and will not leak. “

It has been claimed that the Captain Sandstone site could hold up to a century’s worth of emissions, but Underhill says its formation includes “few barriers to arrest gas escape” and the geology suggests the pollutant would return to the surface.

He went on: “We should be focusing attention on sites where CO2 has been found already as that proves that the trap and seal works on geological time scales. Although these sites are the exploration disappointments of the oil and gas companies, they present a clear opportunity for carbon storage.”