Worlds largest coal exporter, at near 40% of the world's coal, puts Australia as the third highest global export source of CO2. Behind only Saudi and Russia (oil and gas respectively).
I'm not sure it's fair to count a country's fossil fuel exports to its CO2 contributions. Arguably Australia could increase the price of coal by stopping its coal production but the effect would just be that mines elsewhere would reopen or increase production to meet demand.
I'm not sure it's fair to give production and export a free pass in the accounting, as we do.
If coal prices increase it strengthens the case everywhere, for switching to alternative fuels. More solar, wind, hydro schemes will start, and some will replace coal with gas -- which although fossil is, at least, a step in the right direction. Of course mines may reopen, but if the world is ever to be serious about solving the problem that should be restricted, regulated or taxed by the nation with the reopening mines.