New York Times science reporter Andrew Revkin has written a provocative column, "The Endless Pursuit of Unnecessary Things," on his always interesting Dot Earth blog. The title is from a line attributed to Adam Smith: "An investment is by all right-minded people to be commended, because it brings comforts and necessities to the citizenry. But, if continued indefinitely, it will lead to the endless pursuit of unnecessary things." (I confess my usual sources of Smith arcana could not turn up this quotation anywhere online, but no matter, let's assume Smith wrote it.) Revkin uses the quotation as a launch point for a discussion of sustainable development. He sums up his concerns in two questions:
How many people will inhabit Earth in the next few generations? How much stuff—energy, land, water, marine life—will they consume?
Let's look first at Revkin's population concerns. World population increased from about 1.5 billion in 1900 to 6.5 billion today. Along the way, Malthusians predicted that massive famines would occur. They didn't. Food supplies increased faster than population growth and food became cheaper and more abundant. In addition, the amount of land devoted to farming barely changed. As a consequence of growing food security and the spread of improved public health and medical technologies, global human life expectancy more than doubled. Perhaps the Malthusians are at last right? There are good reasons to think not.
Globally fertility rates have been falling since the 1960s. What does this mean for the future? At the Transvision 2007 conference, Jerome Glenn, head of the United Nations' Millenium Project and author of its annual State of the Future report, pointed out something what I've been saying for years—that the U.N.'s low variant trend appears to be the path that world population is following. If that trend holds, Glenn noted, that would mean that world population would grow to about 8 billion in 2050 and start declining to 5.5 billion in 2100. That's a billion fewer people than currently live on the planet.
So if overpopulation isn't the problem, then perhaps overconsumption is? Americans are held up as the poster children of overconsumption and Revkin's column plows that well-worn furrow with its meditation on "the endless pursuit of unnecessary things." But before looking to see what things are unnecessary, let's look at the resource consumption trends that worry Revkin. He quotes long-time limits-to-growth proponent and current President of the American Association for the Advancement of Science John Holdren on the challenges of sustainability. Holdren (along with his colleagues Paul Ehrlich and John Harte) famously lost a bet with economist Julian Simon that prices of a basket of mineral resources valued at $1,000 and chosen by Holdren et al. would increase between 1980 and 1990. They didn't. Holdren and his colleagues mailed a check to Simon for $576.07.
Revkin also mentions land. So what's happened with trends in land usage? A 2006 study published in the Proceedings of the National Academy of Sciences found that "among 50 nations with extensive forests reported in the Food and Agriculture Organization's comprehensive Global Forest Resources Assessment 2005, no nation where annual per capita gross domestic product exceeded $4,600 had a negative rate of growing stock change." Biotech tree plantations would enable humanity to produce all the timber we need on an area roughly 5 percent to 10 percent of the total forest today. This would mean that more of the Earth's forests could remain in their natural states.
Similarly, the amount of land needed to grow enough food to feed a person has plummeted from about one-and-a-quarter acres in 1950 to about half an acre today. Jesse Ausubel, director of the Program for the Human Environment at Rockefeller University, finds, "If the world farmer reaches the average yield of today's US corn grower during the next 70 years, ten billion people eating as people now on average do will need only half of today's cropland. The land spared exceeds Amazonia. This will happen if farmers sustain the yearly 2 percent worldwide yield growth of grains achieved since 1960, in other words if social learning continues as usual."
And what about water? Americans are using less water per capita too. Water withdrawals peaked in 1980 and have been flat since. All kinds of innovative techniques for stretching freshwater supplies are being developed. An example of that is the low-cost drip irrigation systems designed by International Development Enterprises that can reduce the cost of irrigation in poor countries from about $6,000 per acre to about $37. In addition, strides are being made in developing seawater agriculture.
Overconsumption of marine resources is an institutional problem—fisheries are open access commons which encourage wanton plundering. If a fisher doesn't take a fish, the next guy will, so fishers have no incentive to leave fish in the sea to replenish themselves. This can be changed via privatization and by the expansion of aquaculture.
What about non-renewable resources? This is a tougher issue. Even as workers in modern societies have shifted from manufacturing to service jobs, the raw stuff used to make goods has not declined. We are, however, getting far more value and services out of the stuff we do use. For example, between 1980 and 2000, the amount of stuff consumed in the European Union 15 was essentially flat while their economies grew by 50 percent. As the poor in the developing world become wealthier, they will want better housing, transport, and modern energy supplies. Can the world's resources meet their desires? Again, there are good reasons to think so.
People do not get rich just by doing more of the same—they get rich by doing things better, cheaper and with less stuff over time. As Stanford University economist Paul Romer argues, humans become wealthier by improving the recipes for how we make stuff. Sand and iron used to be just building materials; now we use them to make computer memory. As described above, there are strongly positive trends in the future supply of renewable resources, such as food, fiber, wood, and so forth.
The vast majority of non-renewable material flows are used in construction (housing and infrastructure) and energy production. There is no likely future shortage of construction materials. In addition, fossil fuels will not run out in the 21st century. However, humanity will either have to figure out how to control the pollution produced by fossil fuels or shift away from them because of their deleterious effects on the environment, including their contribution to man-made global warming. There are good reasons for optimism with regard to pollution control. Air pollution in the U.S. has been declining for decades and even China's notoriously bad air pollution may be decreasing. Supplying adequate clean energy is the central challenge to future human well-being. Fortunately, the ideas for sustainably improving and increasing energy, food, and any other form of industrial production are far from being depleted.
Revkin entertains the suggestion by Boston College sociologist Juliet Schor that we should all relax and stop working so hard and instead "opt for a new economic and social vision based on quality of life, rather than quantity of stuff." Quality of life can have all sorts of dimensions, but one important aspect is increased leisure and access to learning. And that's what people in modern societies have done throughout the last couple of centuries, plus getting all the nifty new stuff.
In a 2005 National Bureau of Economic Research study, economists Jeremy Greenwood and Guillaume Vandenbroucke found, "Over the course of the last century there was a precipitous drop in the average length of the workweek, both in the marketplace and at home. In 1830 the average workweek in the market place was 70 hours. This had plunged to just 41 hours by 2002. At the same time there was a 9-fold gain in real wages." In other words, people in modern societies aren't working harder, they're working better. So what do we do to fill up all those extra hours of leisure? Perhaps we buy "unnecessary things" with which to entertain and enlighten ourselves. And then there is that horrible suspicion that most people actually like to work.
Which bring us to the question: Just what are all those "unnecessary things" that allegedly clog our shopping malls? Which does Revkin think we should want to give up? He mentions not a single product—yet the implication is that the mandarins of good taste and restraint know best what the rest of us really need. Our cellular phones? Our iPods? Our pink sunglasses? Our kids' paint-by-number set? The 246 varieties of dog food and 165 kinds of cat food, and even Valentine gifts for your favorite mutt? Necessity, like beauty, is in the eye of the beholder. And in fact, consumers in markets winnow out all kinds of unnecessary things every day.
The Malthusian meme always insists "things just can't go on like this." Of course, if "things can't go on like this," then they don't. Humanity changes course and things get better. At least that has been the story of the last two centuries and the evidence is that it will be the story of the 21st century as well.
Disclosure: I think that the cat toys my wife bought for our two felines are unnecessary. And does she really need that many pairs of black shoes?
Ronald Bailey is reason's science correspondent. His most recent book, Liberation Biology: The Scientific and Moral Case for the Biotech Revolution, is available from Prometheus Books.