THE withdrawal of Shell from the Cambo oil field development is not necessarily the beginning of the end for fossil fuels and transition to a zero carbon energy policy, nor the death-knell for the economy of the north-east. Even if it were either or both of those things, it would clearly not be cause for unqualified celebration or for condemnation.

It is more likely to be an early indication that the choices made in pursuing greener energy and climate ambitions (shared by the governments at Holyrood and Westminster and recently adopted at the COP conference in Glasgow) involve time, difficult decisions, and significant economic costs.

It is possible that Cambo will still proceed; the majority shareholders want to continue talks with the UK Government, which grants the licences and contracts, and – though it has committed to rapid transition to renewables and is conducting a new environmental assessment – is still broadly supportive.

Westminster might easily change its stance, as it may do with a proposed coal mine in Cumbria, in order to conform more visibly with Boris Johnson’s highly ambitious, and apparently sincere, rhetoric on environmental transformation. But ministers are also conscious that fossil fuels cannot be magicked out of the wider economy by the stroke of a pen: recent ructions in the energy market and bankruptcy of suppliers are evidence of the reliance of the domestic market on them. In industry, things are even starker: the steel industry will still require coke and the ceramics industry gas; the 120,000 UK jobs directly tied to oil and gas, many in the north-east, are only the most obvious potential casualties.

In the long run, those jobs will have to follow the example of the mining industry if net zero is the aim. But almost everyone – bar the most unrealistically fanatical environmentalists – wants to avoid the trauma and economic carnage that attended that transition. So far, there’s little concrete evidence of transferring engineering skills to renewables at a rate that even begins to match the fine speeches and grand ambitions devoted to the subject.

That’s why Nicola Sturgeon didn’t get round to declaring that Cambo should not be developed until a couple of weeks ago, after persistently and uncharacteristically refusing to voice an opinion. Her novel, indeed unprecedented, insistence that it was Westminster’s decision to make must have been with an eye to it also taking the flak for failing to live up to its climate aims.

Not that one can blame her in political terms. It’s not surprising that a Government that waves the thistle about should have wanted to avoid grasping this particular nettle. In fairness, that is not just about political expediency, but about many difficult future decisions for the Scottish Government. No one doubts the First Minister’s sincerity on climate change, either, but she will be acutely aware of the potentially catastrophic economic damage, too.

The ambitious declarations at COP were not enough for some environmentalists – one suspects nothing would have been – but they are the most ambitious international targets yet. The reality, however, is that to be achieved, they will require global transformation and expenditure on a colossal scale, and will not happen overnight. Less attention needs to be directed at the “optics” of continued use of fossil fuels, and more to constructive, managed solutions. Whether we like it or not, we cannot get rid of them instantly, and moving faster may not always involve refusing to countenance any development; better, surely, to make a balanced judgment about the real costs and impact, both economic and environmental.

That calls for more investment in new green technologies, training of engineers and scientists, and retraining and support for industries that we actively wish to run down. It’s reasonable to oppose new developments such as Cambo and argue for faster transition to renewables and other options, but it is unreasonable to claim that there are no significant costs to real people’s lives and livelihoods. Any revolution has casualties, and a Green one will be no exception. But it need not be a riot of needless destruction and damage.