TWO thousand feet below the surface of the Midland Valley - stretching from Girvan to Greenock in the west, and Dunbar to Stonehaven in the east - lie shale rock formations which contain gas.

How much of that gas is recoverable is simply unknown. Last month INEOS, who use ethanol as a feedstock at Grangemouth, bought up licences to seek to explore around 270 sq miles.

Until any exploration takes place, assertions and estimations of how much shale gas lies beneath us remain just that - assertions and estimates. Strident claims about shale gas's capacity to slash bills or create thousands of jobs by simplistic extrapolation of the US experience should be treated with considerable scepticism. Too many enthusiasts for a "shale gas revolution" turn this unknown and unquantified resource into a silver bullet to all of our energy problems. The reality is that case just doesn't stack up. The European gas network means we will be unlikely to have a glut of unexportable gas that reduces the price to the dramatic effect seen in the USA, and it is an activity that is likely to only be economically viable when gas prices are at a relatively high level.

But INEOS's acquisition of exploration licences mean that it is likely there will be applications for shale exploration in Scotland in the future. For the most part, this will be managed and overseen by the Scottish Government and local authorities. Planning is a devolved responsibility, and much of the regulation and permitting is overseen by SEPA, a body created by and responsible to Holyrood. If the Scottish government chose to, they could effectively outlaw any exploration or extraction in Scotland by using those powers. Indeed, in May, Scottish government Ministers voted against such a proposal in a Holyrood debate.

There is, though, an anomalous position with mineral access rights, which govern access to gas within a licenced area including beneath land not owned by the licensee. While requiring planning permission within a framework that is set in Edinburgh before being able to undertake any activity at all, mineral access rights are technically reserved. With a different planning system, and without a trespass law which exists in England and Wales, it seems odd that this related secondary part of the process for permission to extract gas is not also devolved. That is why I have suggested in a short but specific submission to the Smith Commission that this should be considered for devolution.

There is an added current relevance to this issue. The Infrastructure Bill, which will probably be considered by the House of Commons next year, proposes reforming mineral access rights. While any disturbance at surface level needs planning permission, mining for coal or laying a gas, sewage or water pipe beneath ground does not require the consent of the owner of the land above. For the extraction of geothermal heat, oil or gas, then it does. When this anomaly was tested in the English courts, drilling hundreds of yards below ground was found to be a trespass but without any detriment and a token compensatory award made.

In proposing to address this inconsistency for activity taking place three hundred metres or more underground without any surface level disturbance, the UK government have caused some controversy. In some quarters, including comments from the SNP's Holyrood energy spokesman, this has been portrayed as a change being foisted upon Scotland while neglecting to mention that it is only with permission granted in Scotland that any exploration or extraction could happen in the first place.

When planning and environmental permitting are already devolved, so should what is effectively a related planning consideration for mineral access. Bringing coherence to the planning process will help Holyrood consider all of these issues, and the public will know precisely where responsibility lies. A small, but significant, contribution that could be made to the enhanced devolution being considered by the commission.