RED and green lanes. They will be vital for peace in Northern Ireland but importing goods via digital data not paperwork has a potentially more important application on another troublesome border – the English Channel. And if it works there, then why not between an independent Scotland and England?

Of course, this is some way in the future. Northern Ireland gets special treatment because of the danger that trade borders might re-establish flashpoints that could derail the peace process. Britain’s case for special treatment is also the main obstacle: size.

How would it look if a large non-member like Britain could circumvent checks and end up with the “best of both worlds” minus payments to Brussels? And plenty humble pie would have to be eaten by a British Prime Minister – be it Sunak or Starmer.

Red and green lanes and trusted trader schemes at Dover would mean Britain biting the bullet and letting Brussels dictate to Westminster again – at least that’s how Nigel Farage and the Brexit-supporting press would characterise the European Court of Justice at the top of any process for adjudicating disputes.

So, it’s not a doddle, it’s not around the corner and it’s not even likely.

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But here’s the thing. Brexit is not done. Not when restrictions on the movement of people and goods is the major cause of Britain’s flatlining economy and this winter, the empty shelves for fruit and vegetables in supermarkets. Of course, bad weather on the continent did play a part. But have Spain and Morocco never experienced bad winters before? Strange food rationing only kicked in after Brexit. So clearly anything that makes the cross-channel movement of food easier will help.

But in a sensible society, a supply chain shock would result in longer-term solutions. Why does the UK import half of its food? Why does Scotland import 70% of its fresh fruit and vegetables? The relatively cloudy and cold winter climate is only half the story. It helps produce the best soft fruit in Europe, root vegetables aplenty and barley destined mainly for cattle feed and whisky. It just doesn’t do the salad items like tomatoes, cucumbers and lettuce which have disappeared from our shelves. But why not?

When Iceland’s economy hit the buffers after the 2008 crash, its currency crashed in value and imports did the same, prompting a rapid response from the Icelandic government which subsidised geothermal technology in greenhouses, enabling a switch from mass importation of tomatoes to home production.

One glasshouse farm at Fridheimar alone produces 370 tons of tomatoes throughout the year – that’s 15% of Iceland’s tomato market. And the glasshouses still get government subsidies for electricity and lighting. It’s called food security. So, 15 years after the crash, the country hasn’t returned to 100% dependence on imports and glasshouses supply Icelanders with bananas, cucumbers, roses and more. It’s the same story in Finland and Russia – all cutting emissions into the bargain.

So why not here? Obviously, we lack the hot springs produced by Iceland’s dangerously volcanic geology. But we have vast reserves of other renewables, especially wind. Thanks to the continuing absence of sub-sea connectors to let that energy leave our northern and western isles to reach the grid, much of Scotland’s renewable resource is ‘stuck’ there.

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So why not follow Iceland’s example and use that excess energy (plus equally important reserves of pure, clean local water) to ramp up investment and turn Orkney, Shetland and the Hebrides into the glasshouse and food security capitals of Scotland?

There are snags – but none is insurmountable. The main ones are Westminster control over energy and agricultural subsidies – along with a lack of verve and imagination at Holyrood.

Horticulture and market gardening have historically failed to receive the production subsidies received by conventional farmers from the EU and now from the UK government. Salad growers were excluded this winter from the Energy and Trade Intensive Industries scheme (ETII) which helps other producers with energy costs, including, bizarrely, the Royal Botanical Gardens.

Without energy price support many greenhouse growers went bust this winter and salad production has fallen to its lowest level since records began, according to the National Farmers’ Union.

One can understand Liz Truss’ aversion to lettuce and Therese Coffey’s preference for turnips, but do Tories just hate salad? You’d wonder. Despite all the exhortation to eat healthily, there is currently more land given to biofuels in Britain than horticulture.

There’s a related problem – small growers can’t get into a domestic supply chain dominated by big suppliers and importers, themselves struggling to supply the steady volumes and perfect fruit and veg demanded by supermarkets. It’s a Europe-wide problem but other countries have done something about it.

France requires 20% of supermarket produce to be sourced locally, public procurement favours local produce (via low food miles) and councils back local markets and give free electric vehicles to market gardeners so they can supply them.

Happily, the recently passed Good Food Nation Bill requires Holyrood and councils to back such ideas. But its main driver, Pete Ritchie, CEO of Nourish Scotland, wants more: “We should copy the Netherlands after WW2, when the government, growers and universities agreed a long-term strategy based on glasshouse production.

“That will mean smarter use of renewable energy and some big freezers to cope with excess produce. Glasshouses need just a tenth of the water used in open fields whereas importing tomatoes essentially means importing water from drought-stricken Spain and Morocco. It's crazy when cities like Dundee have enough green space to produce fruit and veg for half the population.”

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The Scottish Government is establishing a new food security unit, is spending £2 million on vertical farming (on top of £50 million for food-related research) and updating guidance on local food in public procurement. It’s fine but it’s far too little.

Never mind red and green lanes for easier imports in the distant future. Food security starts at home, so we need glasshouse investment, new entrants to this type of farming, local food-buying decisions from councils, schools and universities and energy subsidies from the Scottish Government – now.

It’s a tall order, but the only way to follow Iceland’s example – and have a good food crisis.