The dryness of Australia comes from the fact that current bring cold Antarctic water up to its west coast which leads to dry winds that blow eastward, which com

The dryness of Australia comes from the fact that current bring cold Antarctic water up to its west coast which leads to dry winds that blow eastward, which compounds with the complete lack of any mountain ranges to serve as rain shields to leave most of the continent dry. Even the mountains in the east of the continent are barely high enough to form a rain shield, if they were even a bit smaller then the east coast would be as dry as the rest of the continent. Moist tropical air barely reaches the very top of Australia - instead it hits places like Java, where the abundant rainfall and numerous active volcanoes provide ridiculously fertile land that currently supports 150 million people - 5x that of Australia - despite being 50 times smaller.