27 million people, and growing faster than expected

Australia is home to about 27.1 million people in 2026 by the UN’s count, the largest population in Oceania. The UN’s medium projection has it growing to 32.4 million by 2050, about 5.3 million more¹.

That projection is probably on the low side. The Australian Bureau of Statistics (ABS) already counted 27.9 million people in March 2026, about 2.5% more than the UN’s figure, after a year in which the population grew by 392,700, or 1.4%². The ABS’s own middle scenario for 2050 is 34.9 million. Its low scenario, 32.5 million, is almost exactly where the UN ends up³.

Three in four new Australians arrive from overseas

In the year to March 2026, births outnumbered deaths by 100,600, while net overseas migration added a whopping 292,100 people². So migration supplied about three-quarters of the growth.

Australian women had 1.48 children on average in 2024, and fertility has been below the replacement rate of about 2.1 every year since 1976⁴. Without migration the population would grow only slowly. With it, the country added 1.4% in a single year².

That is also why the forecasts disagree. The UN assumed net migration of about 132,000 a year, less than half of what Australia actually recorded¹². The 2050 figure depends far more on migration policy than on birth rates.

Two-thirds of Australians live in the state capitals

New South Wales is the most populous state, with about 8.67 million people in March 2026. Victoria follows with 7.15 million and Queensland with 5.74 million².

The bigger story is how concentrated those people are. In mid-2025, 18.75 million Australians, 67.9% of the population, lived in the greater capital-city areas. Spread across the whole continent there are just 3.6 people per square kilometre⁵, so a few coastal cities hold most of the country while much of the interior is almost empty.

A world-class reef under heat stress

The Great Barrier Reef Marine Park covers about 344,400 square kilometres⁶, roughly the size of Germany. Between the 2024 and 2025 surveys its hard coral cover fell sharply in the north, the centre and the south. The 2025–26 surveys found early signs of recovery in the north and centre after the crash⁷. Scientists at the Australian Institute of Marine Science (AIMS) see a reef that now swings harder between highs and lows than it used to¹⁴.

AIMS puts the cause plainly: ocean warming driven by climate change¹⁴, the same force behind the global destruction of coral reefs.

A tenth of Australia’s native mammals are already gone

On land, Australia’s isolation produced animals found nowhere else: about 87% of its mammals, 93% of its reptiles and 94% of its frogs are endemic⁸. It has also lost them at what researchers call an extraordinary rate. More than a tenth of its 273 endemic land mammals have gone extinct since European settlement in 1788. Continental North America, over the same period, lost one⁹.

The cause is mostly not cities or farms. Feral cats and red foxes, brought in by settlers, did much of the damage, and they did it in places people barely touched⁹.

That makes Australia an unusually clear case in the global species extinction rate: the losses come with the people who arrived, but not from where they live. It is also why the megafauna that remain get so much attention here.

Digging up the world’s lithium and iron ore

For a country of 27 million, Australia carries an outsized weight in the global economy’s raw materials. In 2024 it mined 43% of the world’s lithium and 38% of its iron ore¹⁰. The lithium ends up in batteries for electric cars and power grids, and the iron ore in steel mills abroad, which means the damage from digging them up stays in Australia while most of the use happens elsewhere.

7.4 Earths of production, from a country with land to spare

Australia’s footprint is measured by what it produces, because the national accounts publish no figure for what Australians consume. If every country produced at Australia’s rate per person, the world would need a massive 7.44 Earths¹¹. That number describes mines, farms and power stations, not how residents live, and as the mining shares above suggest, much of what they produce leaves the country.

The biggest slice, 3.00 Earths, is carbon: the forest it would take to absorb the carbon dioxide from the fossil fuels burned in all that production. Cropland adds 2.20 Earths and grazing land 1.64, the fields and pastures behind Australia’s crops and herds¹¹.

On paper the country can carry it. Australia’s land and seas renew about 12.30 global hectares per person a year, more than the 11.17 its production uses¹¹, so it still runs an ecological surplus.

A coal-heavy grid that is starting to turn

Carbon is the biggest part of that footprint, and the power system is a large share of it. In 2025 fossil fuels still made 61% of Australia’s electricity, with coal alone at 43%¹².

But that share is falling. Power-sector emissions were 23% below their 2009 peak in 2025, even as demand rose¹². If the government hits its target of 82% renewable electricity, its own projections have power emissions falling from 148 million tonnes to 55 million by 2030¹³, a drop of almost two-thirds in five years.

Where Australia is heading

Australia is likely to reach somewhere between the UN’s 32.4 million and the ABS’s 34.9 million by 2050, with migration deciding where. If recent arrivals continued at anything like 2025–26 levels, a rough extrapolation rather than a forecast, the higher figure looks more likely than the lower one.

Most of those extra people will land in a handful of coastal capitals. The pressure they add will most likely be felt there, while the country’s biggest environmental stories, the reef, the missing mammals and the mines, play out far from where most Australians live.