“WICKED problems”, as the policy wonks call them, never go away (which is why they’re wicked). And one of the wickedest – the great tension between economic growth, and saving the planet – came to a head this week. It was a tale of two otherwise implacably opposed governments, coming to a strange, queasy accord.

The first (in Westminster) finally committed to building a third runway at Heathrow. They faced down a storm of protest, triggering the resignation of Tory MP Zac Goldsmith, which throws up a tricky by-election in London’s Richmond Park. The second (in Holyrood, but with a Westminster outpost), pledged support for the expansion.

All going (er) well, we will witness SNP and Tory MPs traipsing together into the same voting lobby of the Commons, in 18 months time.

Not pleasant. But this is also complex. It might be worth carefully stepping through the thicket of arguments on all sides, to see if there’s any clear and common ground to stand on.

The case against the third Heathrow runway, from the eco-perspective, is that it will represent an appalling increase in carbon emissions, which is very likely to burst through the UK (and Scottish) Governments’ own agreed targets – contributing materially to global warming.

But interestingly, the environmentalists also try to push an economic-populist angle. For them, it’s the well-off who cause most of the problem. The median income of travellers through Heathrow is, they say, three times the national average (in Edinburgh Airport, it’s two times).

70 per cent of the total number of flights are taken by only 15 per cent of the UK population. Fifty-seven per cent of the population took no flights abroad whatsoever in 2013.

So it’s frequent flyers, some for business but mostly for leisure, who chuck the most chemtrail carbon into the atmosphere. Reducing their flights would make up the lion’s share of any reduction in pollution. As the New Economics Foundation’s A Free Ride website puts it: “every long haul flight emits as much carbon as everything else a typical person does in a year.”

Thus the calls, from NEF and the Green parties in the UK, to replace the flat rate of Air Passenger Duty with a progressive Frequent Flyer Levy. In short: the more you fly, the more you pay.

However, given that the bulk of the population flies infrequently, the Levy could be designed to respond to that reality. People could be granted one tax-free flight a year, and then see the rate gradually taper upwards.

I’m calculating already. When it comes to flying, one’s own sins of emission are all-too-easily confessed. I have a largely bipolar working existence between Glasgow and London. Given the ebb and flow of gigs and family, it demands a degree of flexible scheduling.

And it’s simply the case that, compared with train travel, short-notice flights are often considerably cheaper. Buses are even better, but you actually lose a calendar year of your life in suffering the trip. (Joking, of course. Not really.)

I’ll also confess to what is the biggest sin in the environmentalist critique of flying – which is taking European and longer-haul flights to conferences and speaking gigs.

I’ve not yet jetted to one that focuses on sustainability, so I’ve been spared that particular hypocrisy. But yes, there’s a status boost, even when folded into the cheap seats on the way to Seoul or Mexico City, that your pet idea has transported you halfway across the planet.

And yes, it can’t be denied that encountering colleagues and collaborators in the same physical space is more effective – that is, it forges stronger relationships, gets more done – than talking to and waving at them down a Skype channel.

Though Skype’s not ineffective, either. So what’s the best tech that gets planet-level enterprise done, but which doesn’t crisp it in the process? The fond hope of the aviation industry is that more fuel-efficient aircraft will partly address the problem, including the idea of electric planes (Tesla’s Elon Musk, predictably, wants to build some).

But electric planes are not going to be easy. If they’re holding the same amount of energy, current batteries are 43 times more heavy than the fuel oil sloshing around in an aeroplane’s tank.

So based on the batteries, these crates won’t travel very far, nor carry many people. We need a massive technological breakthrough here. And even if it happened tomorrow, it would take decades to become the industry norm. We don’t have that much time left, before we trigger runaway climate change.

So if there is a technical fix for the human practice of globalisation – that is, maintaining world-level business, but not flying around so much to get there – it will more likely be virtual than airborne.

Facebook’s Mark Zuckerberg previewed a new virtual-reality service recently. It’s a headset and network which allows you to interact with cute, full-length animated versions of colleagues anywhere in the world. Every avatar in this cyberspace is able to flip to a different location, show their material, even mutually handle 3-D digital objects, all fluently and easily.

This prompts me to send a small development note to the Scottish Government. Given our bleeding-edge advantages in computer games and informatics, it might be worth trying to establish ourselves as a world-leader in virtual meeting-spaces. At least as much as hitching our wagon to massive increases in air flight.

However, it’s not difficult to discern the core agenda behind the Scottish Government’s firm endorsement of the Heathrow Third Runway – nor its bid to reduce Air Passenger Duty across the board. For example, various Scottish forces (in tourism, retail and the arts) have lined up behind a world-wide marketing campaign, bearing the hashtag #scotspirit, and brimming with footage of clear-flowing rivers and spotless beaches.

Those tourist dollars won’t be arriving by vintage charabanc. Yet there’s something a bit off here. We peddle mossy visions of heathery ecotopia to global consumers, whose primary means of getting here makes it considerably worse for those most acutely affected by global warming.

As green campaigner George Monbiot put it the other day, “the people of future drought zones will feel so much better” when they hear that ministers “have paid ‘full and proper heed’ to Heathrow 3’s environmental consequences”.

At First Minister’s Questions on Thursday, Nicola Sturgeon talked about “difficult balances” to be struck between climate and economy, and that environmental efficiencies would have to be found “elsewhere” in Scottish society.

Again, this goes along with the mainstream consensus. As noted above, compared to other sectors seeking to reduce their carbon output, airflight is a much tougher nut to crack. Aviation’s “business as usual” can’t just be efficiently re-engineered under its surface, as it can for other forms of transport or industry – or at least, not remotely at the same rate. So, “frequent flyers must fly less”, is the injunction from greens.

Yet the idea of flight reductions also cuts against one of our cherished collective ambitions at the moment, in a post-Brexit Scotland. Ostentatiously, we want to be a home for cosmopolitan talent and overseas investment of all kinds, as we strive to establish either a “special status” or full independence in Europe (and, by the way, increase our tax base). Again, there’s primarily only one way that this circulation of human talent and interest would be physically enabled.

So if an increase in air travel is a key mechanism for a small, open, flexible, modern economy like Scotland, do we simply stop our ears to news of the polluting externalities it generates? “Sorry, we’re growing, not listening?”

A lot can – and most certainly will – happen in 18 months. But it may not always be the case that the Scottish interest, and the planet’s interest, coincide. My own actions, and the conclusions I draw from evidence and conviction, don’t line up either. But wicked problems need full and frank national conversations. This one starts now.