It's not as much as you may think you have to learn though. Once you understand the general characteristics of globalisation/global economy you can discuss it with reference to the world as a whole. If you know a few stats and have a qualitative grip on australia's progress in the past 20yrs you should also be able to manipulate ur info fairly well to spk about australia. Similarly, an understanding of another country can then be used specifically for the case study, and also to back up anything you may say about the global economy as a whole.
E.g globalisation has done *blah* as can be seen in *thailand/singapore/china/indonesia* as well as *blah* as may be seen in USA/euro area etc etc...Practice using ur info efficiently - if you know anything, throw it in in an effective manner, rather than thinking about it as finite pieces of info "oh this is topic 1, this is topic 2" etc etc
. To be honest, for my globalisation question last year, my first few pages was stock stuff from the text, then i kinda got bored and basically spoke about what i'd read in the economist over breakfast that morning...If you have general knowledge, use it