Ian McLean QSO: The Grey Rhino of Population Decline

New Zealand faces a grey rhino event. We now feel the impact of the NZ birth rate dropping.

Across the world it’s happening. Birth rates are well below replacement. Workforces are tightening. Populations are ageing. The cost of pensions and healthcare is rising.

We in New Zealand rely heavily on immigration to staff hospitals, farms, and core services, but global competition for skilled workers is intensifying. Richer countries are scrambling for skills. Immigration can no longer be relied on to solve our problems.

The global nature of the change is obvious but unrecognised. That is called a ‘grey rhino event’.

Awareness of the impact of low fertility has risen, country by country, over the past year or so. Yet it is still almost always framed as a national problem rather than a global one. Each society sees its birth rate falling and assumes its predicament is unique. In fact, the pattern is shared across most of the world. The global nature of the shift is obvious once seen, but rarely acknowledged.

New Zealand treats these pressures as local issues. They are not. Our future will be shaped by the global population shift, even as our own policies determine how well we adapt to it.

For much of the twentieth century, the world population grew faster each year, in exponential growth. That changed about 1964. Since then, growth has slowed steadily, driven mainly by falling birth rates rather than falling death rates.

Country by country, population growth is turning into decline. What is happening now is the mirror image of twentieth century population growth, operating in reverse across generations.

The key measure is the Total Fertility Rate, the average number of children a woman is expected to have. A Total Fertility Rate of about 2.1 is needed for long term population stability. Around two thirds of the world’s population now live in countries below replacement fertility, including China and India. Populations in East Asia are already shrinking. So too in Europe, although some countries are partly protected by immigration. Sub Saharan Africa remains above replacement, but there too fertility is falling.

Because of population momentum, total world population has yet to peak and will not do so for another 50 years or so. But momentum works both ways. Fewer babies today mean fewer mums tomorrow. If fertility stays low, decline becomes self-reinforcing.

This downturn differs from earlier population falls caused by famine, disease, or war. It is driven by social change: rising prosperity, education, urbanisation, lower child mortality, and access to contraception. It reflects women’s choices as they have gained greater control over their lives.

There are benefits. Slower growth eventually eases environmental pressure. But fewer babies today mean fewer workers tomorrow. Labour shortages emerge long before total population falls. Populations age. Pension systems and health services come under strain.

New Zealand already feels the first ripples. Our population still grows because of immigration and demographic momentum, but births are well short of those needed to avoid long term decline. Skill shortages are already acute.

Global competition for workers will intensify. Richer countries are bidding for the same shrinking pool of talent and can outbid us for our own skilled people. We need to build the skills of our own people and then retain them, rather than rely on immigration.

Fewer young people are available to support the growing proportion of older folk. The costs of healthcare and New Zealand Superannuation are rising and increasing pressure on government finances.

New Zealand needs a plan. No part of the existing government system is equipped to provide one. A task force is needed to develop an integrated response. We need to repeat the successful approaches of the Woodhouse Commission on ACC, and the Picot Committee’s Tomorrow’s Schools.

The likely elements are already clear. Productivity will have to rise through innovation and technology. Economic growth per head will need to be strong enough to sustain living standards and support an ageing society with a smaller workforce. To eventually halt population decline, the role of women needs to be enhanced and parenthood supported much better.

We also need to take account of the long term prospects. Because the current fertility decline is unprecedented, long‑term outcomes are hard to predict. But the projections of current trends are frightening. These projections are not forecasts but they show what happens if nothing changes.

Civilisation may not unravel with a bang. It may shrink generation by generation, empty cradle by empty cradle. The first ripples are already affecting New Zealand. New Zealand needs to plan for the consequences of falling global fertility.

Ian McLean QSO

Rotorua

January 2026