It is sometimes helpful to view great issues of the day through my Hebridean prism, from which greater truths can be extrapolated. Take, for example, the drive for net zero.

The Western Isles has the highest level of fuel poverty in Scotland; maybe, for all I know, the Western world. That, one might think, should make it an eminently suitable testbed for linking decarbonisation to community benefit. Nothing could be further from reality.

A report went to the local authority last week which put the cost “to decarbonise heat and improve energy efficiency under a high ambition scenario for the Western Isles” at “over £500 million”. In other words, half a billion to meet the Scottish Government’s targets by 20-whenever-it-is.

I’ll let you into a secret. It isn’t going to happen. The council is skint. Much of the housing stock is unsuited for standards that apply in Broomhill or Bearsden. In fact, for the past 18 months, an insulation programme which was making steady progress has ground to a halt following new national regulations.

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If anyone can tell me where £0.5 billion, or a fraction thereof, will come from to meet “targets” in respect of 0.5 per cent of Scotland’s population, then I will willingly stand corrected. I don’t care who provides the answer – Rishi Sunak, Humza Yousaf or, if we really scale the heights of virtue, Patrick Harvie. But if nobody can answer it, the targets are a fraud.

Now, I concede that the Western Isles is not typical. More than three-quarters of properties have Energy Performance Certificate ratings of D-G, compared to a Scottish average of 13 per cent. But there are plenty areas where rurality or the condition of urban housing stock presents challenges of similar scale, in different forms.

Targets that cannot be met are meaningless. The real world needs pragmatism and respect for the challenges households and communities face. The good should not be made the enemy of the best on the altar of “green” rhetoric that shows no sign of being fulfilled.

We are constantly told Scotland has “world-leading targets” for this, that and the next thing. The Scottish Government website proudly informs us: “Scotland’s net zero emissions target date of 2045 is ahead of many other countries, including the UK whose target is to reach net zero by 2050”. It is unlikely the authors of this claim will be available for verification by either date.

Meanwhile, it is safer to judge according to actions and to avoid the cross-fire which intensified following Rishi Sunak’s reverse Damascene conversion last week. It was a shameless exercise in lack-of-virtue signalling directed towards a lowest common denominator. Any sense it contained was disguised by the rhetoric in which it was wrapped.

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In that way, an unproductive polarisation has been further entrenched. Those who set targets which cannot be met or are regularly missed (as in Scotland) preen themselves on their own righteousness while Sunak casts himself as the pantomime villain, in pursuit of a crude political gambit.

The response to Sunak’s re-positioning encourages hope that he has got it wrong. There are plenty Tories who are appalled by his opportunism. Industries which shaped investment plans to meet previous pledges are outraged. Instead of bringing clarity to purpose and strategy, there is even greater confusion and cynicism.

Naturally, the question of whether there was any prospect of targets being met has been sidelined in favour of a new front in the culture wars. Just as in the Western Isles however, there are real life tests to be applied. What is actually happening to make progress towards net zero targets, at affordable cost, regardless of date? My guess is: “Not a lot”.

Sunak misses the point that most people want to do the right thing and make their contribution. What is missing is any sense of national mission, either in Scotland or the UK, which sets out a route map to be followed, rather than a hotch-potch of random initiatives which invariably turn into political rows and barriers of affordability.

The big picture of where our energy comes from is scarcely more encouraging. Without reliable alternatives, the default position is to rely on gas. Arguing about its source is a secondary debate and it will be difficult to persuade anyone that increased imports make sense while at the same time putting the black spot on the North Sea.

More pertinent questions are about how the alternatives are coming along. Within the past few weeks, the subsidy scheme known as Contract for Difference, failed to advance a single offshore wind project due to the Tories refusing to recognise where this Dutch auction was heading. Another year lost; another blow to investor confidence in UK renewables.

At the same time, it is increasingly apparent there is no done deal for grid connections to facilitate offshore wind. Put these two factors together and the message is pretty clear that targets for decarbonising our electricity supply by 2030 are already under severe pressure which means higher costs to consumers, not lower.

Since Sunak’s primary purpose was to create blue water between Tories and Labour on the net zero agenda, there is no prospect of a war of words subsiding this side of a General Election. In Scotland, there will continue to be more interest in virtue-signalling than actual delivery (though the Scottish Government could astonish me by answering the half billion pound Hebridean question).

The truth is that most of energy policy need not be particularly party political. Pretending otherwise plays into the hands of the extremes – on the one hand, those who are contemptuous of the chasm between rhetoric and realities; on the other, those who will seek cover for doing as little as possible.

There is a vast middle-ground of reasonable people who recognise the challenge and want to do the right thing within reasonable parameters. If they really care about outcomes rather than posturing, that is the market to which politicians should be offering leadership.

Brian Wilson is a former Labour Party MP and Energy Minister