Last year, a British oil exploration company and a tech start-up joined forces on a project to permanently lock away untapped fossil fuel reserves in Greenland.

The idea was simple: the energy company, Greenland Gas and Oil, would not extract oil from an area on the east coast that it had exploration licences for. Instead it would monetise keeping the oil in the ground via a partnership with the tech company, Carbonbase, which works on offsetting carbon emissions.

The mechanics were more complex. The partnership aimed to sell NFTs, digital collectibles that come with ownership certificates, linked to the unexplored land. The profits would then be used in part to compensate the energy company and the oil would stay underground. And, since the Greenland government had stopped issuing new exploration licences, the energy company would not be able to simply apply for another and tap a different part of the country.