Sustainable Population Australia (SPA) has welcomed the latest figures showing registered births fell by 3.7% in 2020, and dismissed concerns expressed by former Treasurer Peter Costello.
The Australian Bureau of Statistics (ABS) also reported that the total fertility rate was at an all-time low of 1.58 babies per woman.
SPA National President Ms Jenny Goldie says Australia has not been living sustainably and continuing population growth rates just exacerbate the problems.
"There has been continued encroachment on agricultural lands and forests for urban development; infrastructure failing to keep up with ever-expanding numbers; and, until Covid, crowding and congestion.
"The fall in the birth rate and fertility probably reflected the uncertainties surrounding Covid, particularly in Victoria where lockdowns were most severe.
"It may also reflect the astonishing blow out in housing costs, both to buy and to rent," says Ms Goldie. "One might also hope it reflects increasing awareness that we cannot continue to grow our population as we have been and expect a sustainable future.
"Whatever the reason, there is certainly no reason to panic; rather, the news is welcome. Pre-Covid population growth rates were one of the highest in the OECD and more than twice the OECD average. A slowdown is thus eminently desirable.
"Even with this slowdown, Australia's population is still growing and will continue to do so even with 1.58 fertility and low migration. This fact is not grasped by some media commentators and politicians.
"Ideally, Australia's population size and growth rate should be assessed against their effect on the overarching national goals of human wellbeing and ecological sustainability.
"The empirical evidence over recent decades, however, shows that population growth is associated with a decline in both our wellbeing and life-supporting ecosystems.
"There has been continued encroachment on agricultural lands and forests for urban development; infrastructure failing to keep up with ever-expanding numbers; and increasing crowding and congestion which has only now reduced slightly due to Covid.
"We need to stabilise our population numbers for the sake of sustainability. Low birth rates allow for that."
According to Ms Goldie, demographic research has found that low fertility and gradually declining population can maximise standards of living, ensuring high employment levels, good infrastructure provision, improving environments and low debt levels.
"No matter how low Australia's fertility falls, we have more than enough prospective migrants to top up any shortfall," says Ms Goldie. "Pre-Covid net immigration levels were around four times greater than we would need, even with fertility below 1.6."
To achieve a stable and sustainable population, Ms Goldie says falls in the birthrate must be accompanied in the long-term by low net migration, around 60,000 annually.
"We should not revert to the ridiculously high pre-Covid levels of around a quarter million people a year," she says.
"Every new person, be they native-born or migrant, costs more than $100,000 in public money to fund the extra infrastructure. The environmental costs of this growth are grievous and never-ending. Not least, it will undermine whatever efforts we make to achieve emission-reduction targets including Net Zero by 2050.
"With Australia's per capita greenhouse gas emissions one of the highest in the world at around 21 tonnes per person, any growth in population is going to add to our total emissions."
