Unlike the UK and some others, many of the big exporters - Saudi Arabia especially comes to mind - have essentially no economy beyond oil and oil processing. As the rationing in Iran already suggests, one way or another they will do what they must to sustain some exports as they have nothing else to fall back upon. So it will be a while before Jeffrey Brown's curves actually cross over globally and the worldwide export market disappears.

But as to predicting the exact quantity of net exports, and the role of long term contracts vs. the spot market, there is simply no telling. Such things will follow from political decisions, which are capricious, arbitrary, and often irrational. Which is why are discussing it at all: it is a concern, just maybe less of a concern than the Mad Max Doomers would have us believe.

In any case, one reasonable side bet is that when forgoing coal becomes a matter of freezing in winter - rather than, as now, a matter of spitefully sticking it to evil wicked Big Business and sentimentally whining over useless, dangerous, brutish polar bears, it is unlikely that coal will continue to be forgone.