This is a guest post from Mark Reynolds, a supply chain and sustainability consultant in Sydney.

Let's imagine world oil supply suddenly drops by 10, 20 or 30 percent, more or less overnight, for several weeks or months to come. Don't worry about how or why – we can all think of ways a sudden oil shortage could arise. The more interesting questions are how we respond and what local impacts would follow. At the international level there is sure to be argy-bargy among countries over who gets what from where and how much we pay. It is hard to predict how these global issues may play out. In the case of a serious shortage the ways we share the remaining oil supply and set global prices will be a matter of life or death for some countries, particularly the smaller and poorer ones, so let us hope the international community surprises us with fairness.