Some say humanity’s ever-rising environmental impact is about to go into reverse. Fact or just fantasy?
HUMANITY is doomed. Or it was in 1798, when English scholar Robert Malthus published his influential An Essay on the Principle of Population. Malthus predicted that unchecked growth in human numbers would condemn our species to a “perpetual struggle for room and food” and an unbreakable cycle of squalor, famine and disease. Nearly two centuries later, biologist Paul Ehrlich was no less pessimistic. We had exceeded the planet’s “carrying capacity”, he declared in his 1968 bestseller The Population Bomb. “The battle to feed humanity is over. Sometime between 1970 and 1985, the world will undergo vast famines. Hundreds of millions of people are going to starve to death.”
In 2012, our mood has hardly improved. The focus has shifted from how to feed ourselves to our rapacious appetite for energy and raw materials, and the greenhouse gases we pump into the atmosphere to satisfy it. Sooner or later, the argument goes, we must send our planet’s climate and ourselves past the point of no return – if we haven’t done so already.
Might these reports of our imminent demise also be exaggerated? That is the reasoning of those who see a pattern in recent statistics from the industrialised world. People in the US are driving less. Europeans are using less energy. Water use is down in countries such as the US and UK; so is calorie consumption in the UK.
The talk is of “peak stuff”: that beyond a certain level of economic development, people simply stop consuming so much. Technology and the course of economic evolution allow prosperity to keep rising without a linked increase in our use of energy and materials. Our demands on planetary resources stabilise – and ultimately begin to fall.
Others are unconvinced, seeing in peak stuff a dangerous myth and a thinly veiled excuse to abandon efforts to limit our planetary impact. Without large-scale intervention to curb our excesses now, they argue, peak stuff, if it exists, will be too little, too late. So who is right? Is humanity really about to lose its appetite for stuff – and if so, will it help?
Predictions such as those of Malthus and Ehrlich fell down on a simple point: they failed to see what came next. Malthus missed the industrial revolution and its ways of mass production, which ultimately allowed more people to live longer and more comfortably. Ehrlich failed to factor in the “green revolution”, the widespread use of more productive crop strains and chemical fertilisers and pesticides that has kept food production ahead of the population curve since the 1960s. Perhaps we are missing a similar trend now.
Although Ehrlich arrived at the wrong conclusion, his analysis provides a useful framework for assessing arguments about peak stuff. Ehrlich described our planetary footprint as the product of three factors: how many of us there are, how much each of us consumes and how we produce what we consume – that is, the prevailing technology.
Much of our ballooning impact on the planet is down to the first factor, population. Thanks largely to medical advances ensuring that, for the first time in human history, most children get to grow up, our numbers have quadrupled over the past century to seven billion. We are adjusting our behaviour at the same time: women today have 2.5 children on average, half as many as 40 years ago. In much of Europe and east Asia, including China, that number is 1.6 or lower, below the rate needed to maintain population sizes. That leads demographer Joel Cohen of Columbia University in New York to predict that “many of us may live to see population peak in the middle of this century”. If so, that would fulfil the first necessary condition to begin to reduce our demands on the planet.
Not everyone is so sanguine. For a start, even small changes in fertility make a big difference to our numbers over time, and in sub-Saharan Africa fertility rates are still mostly above 4. “African fertility is falling, but more slowly than many of us expected,” says Hania Zlotnik, until recently chief demographer at the United Nations. The UN’s projections for world population in 2100 range from 15.8 billion and rising to 6.2 billion and falling. The middle projection is for a roughly stable 10 billion (see “Peak planet: Population”).
Even if population growth is at the lower end of expectations, reaching peak stuff would still require each of us to consume less – which brings us to Ehrlich’s second metric.
On past performance, falling consumption looks like wishful thinking. Since 1950, world population has risen by a factor of 2.7, but our use of materials such as metals and oil has quadrupled, and greenhouse gas emissions are up more than fivefold. Proponents of peak stuff point out that this masks one significant positive trend, however. Since 1950, the world’s economy has grown sevenfold, easily outpacing our resource consumption. Every year between 1973 and 2008, according to the US Energy Information Administration, the US gained an average of just under 3 per cent more economic benefit from every unit of energy consumed.