Physically speaking, it is likely that Australia’s geography will not change in many very dramatic ways. Australia is a continent that is not seismically active and so it is not likely to undergo any major changes to its landforms. It may, however, have its physical geography altered to some degree by global warming and by the demands for water on the part of its populace. It has already had problems with river levels dropping and with terrible wildfires. These may continue.
The more likely changes will be in Australia’s human geography. For one thing, Australia is likely to become more Asian in terms of its demographics. For a long time, the government pursued a “white Australia” policy, but this is no longer sustainable given that the world generally disapproves of racism. Politically and economically speaking, Australia is also likely to orient more towards Asia in the years to come. This is because China’s economy and influence are expanding in this region. This means that Australia’s culture, political, and economic geography might change to some degree to make the country more appealing to potential customers and trading partners in Asia.