This week, the government has approved a coal mine at Whitehaven in Cumbria, the first new coal mine in Britain in about thirty years. One of the supporting arguments is this: if we don’t produce the coking coal ourselves, we will just end up importing it.

This assertion is dubious for several reasons, including the fact that most of the coal would be exported (I use “would” rather than “will”, as the government’s decision is certain to be challenged, so the development is still not certain); British Steel maintains the Cumbrian coal might not be suitable for its plant; and Tata Steel plans to shift away from coking coal to cleaner production methods within a decade. So the coal might end up being not here, not usable, or not needed.

Another dubious aspect is the “zero sum” assumption: the idea that whatever we produce in Britain will displace an equivalent volume somewhere overseas. Michael Gove hinted at this in his reasoning that emissions from steel-making are inevitable either way. The Conservative MP for Workington, Mark Jenkinson, went so far as to say that there is “no sense in importing all of our coking coal, which would be an abdication of our climate commitments”. By his logic, developing the Whitehaven mine apparently shows climate leadership!

The “zero sum” assumption is invalid for the simple reason that with any market commodity, if you increase its supply then you put downward pressure on its price, which leads other things being equal to an increase in demand. It might be that the downward pressure is small if the price-setting part of the supply curve is relatively flat, or if there is counteracting fiscal action, or if the developer is an international company which was clearly going to develop just one project – either in Britain or abroad. But unless the government can demonstrate that such is the case, the more credible assumption is that developing Whitehaven would have an upward influence on the overall consumption and greenhouse gas emissions from coking coal.

A common psychology

“Zero sum” is a common psychology, which crops up in other ways in the environmental debate. For instance, frequent flyers frequently argue that “the plane is going anyway” and if you don’t take the seat, someone else will. Companies – including West Cumbria Mining in this instance – argue that if they don’t undertake certain polluting activities, then their competitors will; and they will be less bad than their competitors, honest. And countries such as the UK, in using a production-basis for measuring greenhouse gas emissions and blaming China in particular for wrecking the world, pretend that their consumer demand has no effect on the emissions from those producer nations.

I guess there are various psychological motivations at work. We hate the thought of someone else getting what could be ours, and us not, whether it’s a holiday abroad or corporate profits. We don’t want to take responsibility for consumer behaviour: if it’s legal that’s OK, isn’t it? And, to be fair, it is hard to see how the actions of an individual, or even a small mining company, can have any influence on the global stage. It is likely to be both small and hard, perhaps impossible, to measure.

The trouble is that the world is made up of small and hard-to-measure influences. Cumulatively, they become seismic.