The biggest driver of Australia's increased emissions is the increasing population: https://www.macrobusiness.com.au/2017/07/greenhouse-gas-emis... Under current immigration settings Australia will reach 40 million people by 2050.

With zero net overseas migration, the population would stabilise at 27 million then fall slightly. This is the most important change that could be made to assist the Australian environment, but sadly discussing immigration is completely disallowed in mainstream Australian media.

There is no need to limit birthrates - they are already sub-replacement in Australia. Just cut immigration.