Great response Rics. The depth of conversation much appreciated. The great analytical debate on this forum far outweighs any other I have seen.
DA Morgan, being a statistician and studying it at university for 8-9 years, I do know a lot about Monte Carlo analysis. In fact I started my Masters Thesis on it, before changing. Obviously, it's basically a simulation. But if you have the data, there's no reason to simulate it if you are looking at trend analysis.

He's basically using a simulation to get random areas of which to grab temperatures from, something which isn't necessary if just studying Australia. If he used longtitudes as well instead of just latitudes, then monte carlo would also be not necessary