Back in 1982, when I was working with some operations researchers on the Energy Information Administration's International Coal Trade Model (ICTM), we kept running up against the question of how to deal with the very large potential coal supplies of Australia and South Africa, which if those countries cared only about covering costs (including a normal profit) could have theoretically supplied most or all of the international market (about 10% of total world coal consumed).

One scenario we therefore built into the model allowed for a non-cooperative Curnot-Nash equilibrium, which would involve both countries exporting less and at a higher price (ceding some of the market to a competitive fringe), thereby earning a higher profit.

As a caveat, however, we noted that for a country like Australia, mine owners with foresight would realize there would be a risk to sitting on unsold, economically exploitable coal reserves, should the world start imposing policies to limit atmospheric emissions of carbon dioxide. It might therefore be rational for them to forgo some higher profits in the short and medium term (some of which were being skimmed off by the state-owned Queensland railways) in order to sell more of their coal while the going was good -- i.e., before the fuel started loosing its market.

That was not offered as advice, I should add, but was simply our analysis of what we saw at the time would be the possible ways in which the trade might develop.

These are only my personal opinions.