Many well-informed people are worried about hydraulic fracturing, the "unconventional" process by which gas and oil are forced from deep underground.

Sceptics fear pollution, geological uncertainties, despoiled landscapes, the effects on carbon emissions and communities alike. Those in doubt - or openly hostile - have a point.

There is something a little glib about advocates of "fracking". They talk too easily of trillions of cubic metres of shale gas and billions of barrels of oil waiting to be harvested. Too often they ignore the bans imposed by other countries, or the evidence of disruption and pollution in the United States.

Fracking's advocates are too quick to depict a bonanza without a cost. They speak of energy independence, not of community choices and natural beauty. They promote another chapter in the carbon economy without acknowledging that oil and gas are part of the planet's travails.

Above all, those who demand fracking avoid talking about price. Is the process viable at present? In the US, plans for the shale basin have been scaled back. As a rough rule of thumb, an oil-equivalent of around $77 makes fracking viable. At the time of writing, the Brent Crude price is $49.60. Why the rush to drill?

And why the rush to drill in Scotland? Of the estimated metric "trillions" in these islands, Scotland might possess five per cent. Nevertheless, Ineos has licences for 729 square miles adjacent to its Grangemouth plant. The firm says a £640 million investment "could" follow if - the usual Ineos attitude - it is not obstructed.

This is a moment to step back. As with North Sea oil, Scotland is a country with noble aspirations and a lucrative carbon legacy. Providing light, heat and power in a risky modern world is no small matter, meanwhile. We have done well with renewables, onshore and off, but we are far from secure. And for every wind farm there is a protest.

We do not, supposedly, care for nuclear. We do not wish to burn coal. Our North Sea rights will provide an environmental challenge for generations. Wind farms are questioned. Now, with some sound reasoning, many want no truck with the frackers. So what follows?

Fergus Ewing, Energy Minister, has announced a moratorium on planning consents for the hydraulic technology. Such is the extent of his present powers. Jim Murphy, leader of the Labour Party in Scotland, has meanwhile seized another opportunity by claiming that, with the promised powers of the Smith Commission, he would impose a "triple lock" on decisions.

This is not the view of Labour across the UK and it is not, however advertised, "a ban". It sits oddly with Mr Murphy who, in 2009, spoke up for an expanded nuclear power programme. That, no doubt, is politics. The political question now over fracking is a question involving Grangemouth, our only petro-chemical plant, and the Ineos multi-national.

When and if new powers are granted to Holyrood, planning standards must remain sacrosanct. There must be no free for all. Mr Ewing's intention to examine the health and environmental implications of the technology is therefore to be welcomed. We need a better idea of what is at stake.

It is possible, too, that a harder truth must be mastered. Perhaps there is no such thing as truly clean or genuinely cheap energy.