DIFFICULT decisions. Politicians do like to trumpet their willingness to take them. Here’s Nicola Sturgeon in June, talking about ongoing lockdown restrictions in order to contain coronavirus: “We may still have to take some really tough and unpopular decisions in the weeks ahead, and will have to do so against the grain of what you might like.”

Reassuring words there, and not at all unusual. The First Minister frequently reminds us of her commitment to the righteous path over the easy one, as a cursory glance at her past speeches reveals. In February 2016, her pledge was to make tough decisions over health and social care; in May 2015, she was going to face the music on the education system.

Odd, then, that her government isn’t willing to withdraw support for the expansion of Heathrow Airport, an ill-timed project that would boost carbon dioxide emissions in the middle of our rapidly-closing window of opportunity to prevent runaway climate change.

It’s almost as if ministers like to talk about cutting carbon emissions more than they like to make the tough decisions that would actually support that goal.

It shouldn’t even be a terribly difficult decision. The Scottish Government has already rather boldly scrapped its long-held high-profile commitment to abolishing air passenger duty, and withstood the backdraft from that, so why not this? The justification for Heathrow expansion is that it would be good for business but isn’t this the perfect moment to push sustainable alternatives to frequent business travel, as part of the green recovery ministers say they are committed to?

And hasn’t the High Court in London made the decision easier by ruling that the Heathrow runway plan is unlawful because it doesn’t take climate emissions into account? (Even the UK Government isn’t appealing the ruling, though the airport itself intends to.)

The tide seems to be going out on this project which makes the Scottish Government’s apparent support for it all the more perplexing.

A year ago, the mood music was rather different. Questioned about it, Ms Sturgeon said she would review support for the Heathrow third runway through the “new lens of climate change”.

She could hardly say anything else, given that she’d only just declared a “climate emergency”.

Fourteen months later, this week, here’s what the transport minister Michael Matheson has said: “We remain committed to the memorandum of understanding between the Scottish Government and Heathrow. We are clear that expansion of the UK’s only global hub airport should deliver benefits for all the nations of the UK.” It was essential for Scotland’s “international connectivity”, he said, supporting economic growth, trade and investment. “As these reasons remain valid we have not considered withdrawing from the memorandum of understanding.”

Not considered it? Even though Ms Sturgeon said her government was reviewing it? Oh dear.

The Scottish Government appears to be trying to face both ways here. It has been at pains to play down the significance of its position, saying that it has no control over whether or not the runway plan goes ahead and the memorandum was only about ensuring Scotland benefited if it did.

Ach, come on though. If you want Scotland to benefit economically, then you have to take responsibility for the extra emissions that come with it. To be clear, a third runway at Heathrow would result in around 5,000 extra flights a year from Scottish airports, which would create hundreds of thousands of extra tonnes of carbon dioxide emissions within the following decade alone.

It’s an uncomfortable position for a party that has traded heavily on its environmental credentials. No wonder SNP MPs, who had been expected to back the plan during a key Commons vote in June 2018, suddenly abstained, saying something about there being “no guarantees of the benefits”.

Labour and Tory MPs were divided during the same vote, it must be said. Admittedly it’s not easy for any politician when two priorities seem to require opposite solutions. The business lobby in Scotland has long argued that Heathrow expansion is a good thing and for honourable reasons. Their job is to represent the interests of their members and aviation is still widely and understandably seen as essential to boosting trade, investment and growth.

But it’s the Scottish Government’s job to take a broader view. It’s true that abandoning a third runway could be uncomfortable for the First Minister, given that Scotland is facing a protracted economic crisis and the aviation industry is in the doldrums. At times like this, politicians are expected to do anything possible to boost the economy.

But with Heathrow expansion, the matter at issue is theoretical future jobs, not existing ones, and the inescapable reality is that those come with a climate cost which cannot simply be ignored.

The Lib Dem leader Willie Rennie said in Holyrood that the Scottish Government’s support for expanding Heathrow was “fundamentally incompatible with our desire for a green recovery from the coronavirus crisis”. And perhaps this is the key point. Heathrow’s third runway may never happen anyway, but the Scottish Government’s reluctance to withdraw support for it suggests a mismatch between its soaring oratory on climate change and its willingness truly to prioritise it. This is a government, let’s not forget, that is committed to spending £6bn on two road improvement projects. What climate campaigners fear is this: that in the game of political Top Trumps, economic considerations still outrank environmental ones, no matter how urgent the climate question.

And that’s bad because every day that passes brings us closer to irrevocable climate change. In 2018, the Intergovernmental Panel on Climate Change warned that the world had until 2030 to make "rapid, far-reaching and unprecedented changes in all aspects of society" to prevent drastic effects from climate change. It’s already halfway through 2020. Is the Scottish Government really willing to make those changes?

Heathrow probably should be expanded, one day, when there is proven, green aviation technology that mean planes no longer inject carbon dioxide in dizzying quantities into the upper atmosphere.

But now is not the time.

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