The ability for Australian and New Zealand refineries to switch to light sweet oil (as produced in WA and currently shipped to Asian markets) rather than the heavier crude imports they've been using for the previous 50+ years. What sort of efficiency loss would there be, production delays during changeover, etc.
My own research seems to indicate there's only one refinery in the country in the 1990s that had the ability to quickly switch from one feed stock type to another (up to three times in a day apparently). The others don't seem to have that ability built in.
Knowing what problems and delays there may be is critical to deciding on what's going on throughout the country and may perhaps explain why Australia apparently avoided being nuked.
On another vaguely related topic, I just found this website a moment ago.
http://australiansteam.com
Quote "This site provides an up-to-date listing of all surviving Australian steam locomotives, including their location and status. More than 600 locomotives are detailed, indexed by their state of origin and first user."
Going to be loads of fun trawling through there and figuring out which ones may be pressed back into service when diesel runs short.