The science in this movie is... questionable. Yes it's built on some solid principles. But it ignores certain other principles, just as the alarmists that the guy chose to interview do. Keep in mind that Humans produce less than one seventh of the Earths atmospheric carbon dioxide (the main greenhouse gas that people are afraid of) and that the overwhelming majority is produced by Volcanoes. Keep in mind that we're in an upward temperature gradient that has been going since the dark ages, not one that has been going on since the industrial revolution. Keep in mind that for the last several hundred thousand years, the earths climate has been zigzagging, up, down, up, down. Keep in mind that, in the geological history of the earth, polar icecaps are a uncommon and unusual phenonenon. Yes, ocean currents play a huge role in the Global climate, and yes melting of the icecaps could screw with them. No we aren't looking at a catastrophic climate change that will take place over such a short length of time.
And anyway, if it happens, Australia, being the most stable and possibly most powerful western country in the southern hemisphere, will be in a pretty much ideal position to begin its world conquest... Whee!