In Michael Shreeve's 44 years, Australia has doubled its population. He was born in 1959 in the midst of the populate-or-perish mood. The country was riding a baby boom and had just welcomed the 1.5 millionth migrant since the war. The population reached 10 million that year.
Some time this week - probably Thursday - it will hit 20 million, says the Australian Bureau of Statistics. During this week, a Herald series will examine what this means.
The prospect of another doubling appears unlikely, at least this century. The postwar period has seen a population boom unlikely to be repeated. Now there is a baby bust, and immigration is unlikely to make up the difference. Even if the immigration rate doubled to 200,000 a year, it would take about 80 years to reach 40 million.
Most projections see the population levelling out at about 23-25 million by the middle of the century. Fertility rates declined past the replacement point in the 1980s and continue to drop. It now stands at just over 1.7 children a woman and is forecast to dip to at least 1.65.
The Australian Bureau of Statistics is running a clock. The continent's ecology is already under severe stress because of governmental inaction. Doubling from 20 to 40 million is just not feasible.