Population: How much is too much?

By Peter Meredith 11 January 2011
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The human race keeps multiplying and environmental impact will continue to grow as a result, writes Peter Meredith.

NEAR WHERE I LIVE in the NSW Southern Tablelands, there’s a 400-ha rainforest reserve tucked away in a gorge. On weekends its four car parks are often chock-full and a stream of visitors make the hour-long pilgrimage from the visitor centre along a sturdy boardwalk to a waterfall.

Rainforest like this once covered nearly 23,000 ha in the area. Then cedar-getters and cattlemen arrived in the 1800s. Now three-quarters of it is gone and, outside reserves, much of what’s left is in poor shape. I recall what former NSW premier Bob Carr wrote 10 years ago in a Sydney Morning Herald article. His topic was population and its impact on wild places. “Over the next 100 years treasures like these will be erased from the planet, outside a few struggling game parks or tourist-trampled reserves,” he wrote. “Forests [will be] torn out, grasslands ploughed under, to meet the demands of this vastly expanded human presence.”

Humanity’s presence on this planet is a story of ceaseless growth. From the time our forebears took up farming, more than 10,000 years ago, population expansion has been unstoppable. Whenever we came up with an innovation, such as domestication, new crop varieties or irrigation, the numbers jumped; each advance made our food more abundant, its supply more dependable and our lives more secure.

From an estimated 5 million souls when humankind began farming, the global population reached 250 million about 2000 years ago. It passed the 1 billion mark in 1804, after which the trend went exponential. Humanity hit 2 billion in 1927, 3 billion in 1960, 4 billion in 1974, 5 billion in 1987 and 6 billion in 1999. Our population now hovers near 6.9 billion. It took humanity 12,000 years or more to clock up its first billion – and just 12 to add its sixth. The world’s population is currently growing at 1.15 per cent. That’s about 77 million people a year, 150 people a minute or 2.5 people a second.

Since European colonisation, Australia’s population has grown at an even faster rate than the global average. From about 1 million inhabitants prior to 1788, there are now nearly 22,450,000 people. It is increasing by about 470,000 souls a year, mostly through immigration. And there are more on the way. The world is predicted to have 7 billion human inhabitants in 2011 and 9.2 billion by 2050. The current predictions are that it will plateau at somewhere between 9 and 10 billion. If last year’s growth is anything to go by then Australia’s population will head towards 36 million by 2050 and perhaps 50 million before the end of the century.

Forecast reliability

How reliable are such forecasts? And if they’re right, what will the world be like then? Will there be enough water, clean air, non-renewable resources and food? Experts see food shortage as humanity’s nemesis. Others are more optimistic. In his book Feeding the Ten Billion, Dr Lloyd Evans, ex-chief of the CSIRO’s Division of Plant Industry, says: “Feeding the 10 billion can be done, but to do so sustainably in the face of climatic change, equitably in the face of social and regional inequalities, and in a time when few seem concerned, remains one of humanity’s greatest challenges.”

Feeding all those mouths in Australia and across the world will come at a huge environmental cost. Is it worth it? Who stands to gain?

“The main beneficiaries are business enterprises because they gain additional customers,” says Dr Bob Birrell, director of the Centre for Population and Urban Research at Melbourne’s Monash University. “Governments by and large also are beneficiaries, especially at state level, because they’re very keen to see development in their jurisdictions… They like the economic dynamism associated with extra people, because it means more expansion and therefore more economic activity, measured by cranes on the skyline.”

Long-time Sydney Morning Herald economics editor Ross Gittins doesn’t agree on the wider economic benefits. “Just because it’s good for business doesn’t mean it’s good for the economy,” he says. “Businesses get the benefits of immigration while bearing only some of the costs. The main costs are the need for more capital equipment and…infrastructure, as well as more government services, to meet the needs of the extra people. So governments don’t benefit from immigration; it just increases the demands on them.”

Consuming theories

Modern economies are all about consumption – which requires consumers – and the more consumers there are the bigger an economy gets. “Nothing more preoccupies the modern political process than economic growth,” says Australian National University Professor of Public Ethics Clive Hamilton in his book Growth Fetish. “As never before, it is the touchstone of policy success.” Economists, he adds, are “relentless advocates of more growth as the solution to all problems”.

The trouble with consumption is that everyone wants their cut. Those billions in developing countries who can’t afford our level of consumption today aspire to it tomorrow. Which means consumption will keep growing long after global population peaks post-2050. This in turn means we’ll continue to make the planet less hospitable by felling Earth’s forests, plundering its oceans, damming and draining its rivers, squandering its limited resources and allowing our megacities to metastasise across its surface.

And looming over the many environmental problems we’ve already caused is the spectral threat of climate change, so intimately linked with us, yet so difficult for us to mitigate. Population and climate change are inextricably linked problems. Agriculture is a major emitter of greenhouse gases but, as Clive points out in the book Requiem for a Species: “Population growth will make the task of reducing…emissions much harder because food is the first item of consumption humans must have.”

In Australia, climate change will reduce our capacity to grow food for ourselves – just when our growing population requires us to grow more. As temperatures rise and rainfall becomes less dependable, productive land may turn to dust. With inland areas becoming inhospitable, people will flee to the moister, cooler eastern seaboard. This kind of internal migration, combined with continuing population growth, is likely to encourage the spread of what demographer Bernard Salt calls “suburbia by the sea”.

In August 2009, Federal Labor backbencher Kelvin Thomson made an impassioned parliamentary speech that defied his party’s line on population and spelt out 11 overpopulation-related social and environmental ills plaguing the world. He called on governments and policymakers around the world to “come to their senses and take steps to stabilise the world’s population”.

Although the speech was largely unremarked upon, events in early 2010 thrust the population issue into the Australian mainstream. The Treasury’s prediction that Australia’s population would reach 36 million by 2050, former prime minister Kevin Rudd’s welcoming of the “big Australia” that this represented, the country’s population reaching 22 million in October 2009, and the appointment of Australia’s first Minister for Population, all served to make Australia’s demographic future an election issue.

Sensing the public mood, new Prime Minister Julia Gillard spurned Kevin Rudd’s stance in June 2010, saying she wasn’t in favour of “Australia hurtling down the track towards a big population”. Lobby groups like Sustainable Population Australia and the Australian Conservation Foundation welcomed Gillard’s pronouncement. Although her stance might be taken to imply support for a population cap, no official figure has been canvassed and setting one is difficult.

“There is no such thing as optimum population,” says Monash’s Bob Birrell. “It all depends on your values and objectives. If you’re a businessman the optimum is going to be very big… [But] if you’re concerned about the quality of life of Australian cities, the price of housing or the state of the natural environment, you’re likely to believe we’ve already passed the optimum.” Some studies have put the global optimum at between 1 and 5 billion. Tim Flannery, one of Australia’s best-known scientists and thinkers, has suggested that our nation’s arid and fragile interior and fickle climate make 6-12 million a much more practical carrying capacity.

With the nation home to 22 million and most Australians wary of further growth, it’s not surprising that the optimum figures being thrown around the political arena range between 22 and
30 million. But whatever figure above 22 million wins the toss, we mustn’t lose sight of the fact that our current population is already unsustainable. As the CSIRO noted in 1994 in its submission to the Jones Inquiry into Australia’s carrying capacity: “Every extra person and every unit increase in consumption increase the need to rectify this situation.”

In the end, whether we attempt to stabilise our population at a lower level is up to us. We need to ask ourselves what we want. Is it to be growth or stability, quantity or quality? Is it to be suburbia by the sea, or a continent where there are still wild places to replenish the soul?