Scientific American
August 22, 2005


By George Musser

The 21st century feels like a letdown. We were promised flying cars,
space colonies and 15-hour workweeks. Robots were supposed to do our
chores, except when they were organizing rebellions; children were
supposed to learn about disease from history books; portable fusion
reactors were supposed to be on sale at the Home Depot. Even dystopian
visions of the future predicted leaps of technology and social
organization that leave our era in the dust.

Looking beyond the blinking lights and whirring gizmos, though, the
new century is shaping up as one of the most amazing periods in human
history. Three great transitions set in motion by the Industrial
Revolution are reaching their culmination. After several centuries of
faster-than-exponential growth, the world's population is stabilizing.
Judging from current trends, it will plateau at around nine billion
people toward the middle of this century. Meanwhile extreme poverty is
receding both as a percentage of population and in absolute numbers.
If China and India continue to follow in the economic footsteps of
Japan and South Korea, by 2050 the average Chinese will be as rich as
the average Swiss is today; the average Indian, as rich as today's
Israeli. As humanity grows in size and wealth, however, it
increasingly presses against the limits of the planet. Already we pump
out carbon dioxide three times as fast as the oceans and land can
absorb it; midcentury is when climatologists think global warming will
really begin to bite. At the rate things are going, the world's
forests and fisheries will be exhausted even sooner.

These three concurrent, intertwined transitions -- demographic,
economic, environmental -- are what historians of the future will
remember when they look back on our age. They are transforming
everything from geopolitics to the structure of families. And they
pose problems on a scale that humans have little experience with. As
Harvard University biologist E. O. Wilson puts it, we are about to
pass through "the bottleneck," a period of maximum stress on natural
resources and human ingenuity.

The trends are evident in everyday life. Many of us have had the
experience of getting lost in our hometowns because they have grown so
much. But growth is slowing as families shrink. Ever more children
grow up not just without siblings but also without aunts, uncles or
cousins. (Some people find that sad, but the only other way to have a
stable population is for death rates to rise.) Chinese goods line Wal-
Mart shelves, Indians handle customer-service calls, and, in turn,
ever more Asians buy Western products. Spring flowers bloom a week
earlier than they did 50 years ago because of global warming, and
restaurants serve different types of fish than they used to because
species that were once common have been fished out.

Looking at the present era in historical context helps to put the
world's myriad problems in perspective. Many of those problems stem,
directly or indirectly, from growth. As growth tapers off, humanity
will have a chance to close the books on them. A bottleneck may be
tough to squeeze through, but once you do, the worst is behind you.

The transitions we are undergoing define the scope of the challenges.
Scientists can estimate, at least roughly, how many people will
inhabit Earth, what they are going to need and want, what resources
are available, and when it is all going to happen. By the latter half
of this century, humanity could enter an equilibrium in which economic
growth, currently driven by the combination of more productivity, more
people and more resources, will flow entirely from productivity--which
would take much of the edge off conflicts between the economy and the
environment. Old challenges will give way to new ones. This process is
already evident in countries at the leading edge of the transitions.
The Social Security debate in the U.S., like worries about pensions in
Europe and Japan, is the sound of a society planning for life after

In the public's eyes, demographers have a checkered reputation. Thirty
years ago, wasn't overpopulation the big concern? Paul Ehrlich's book
The Population Bomb was a best seller. The film Soylent Green,
starring Charlton Heston, dramatized a future in which people would be
stacked like cordwood and fed little squares that looked like tofu but
weren't. Lately, though, underpopulation has become the cause celèbre,
heralded by neoconservatives such as Nicholas Eberstadt. Their concern
is epitomized by another Heston movie: The Omega Man, in which
humanity dwindles to nothingness. So which will it be: Too many people
or too few?

Mainstream demographers have not swung back and forth nearly as much
as these extreme depictions might suggest. Families in the developing
world have shrunk faster than expected, but the forecasts described in
Scientific American's 1974 special issue on population have largely
stood the test of time. In fact, the Soylent Green and Omega Man
scenarios each contain an element of truth. Humanity is still growing
enormously in absolute terms, and past success at avoiding Malthusian
nightmares is no guarantee of future performance. The decline in
growth rates is a worry, though. Historically, most stable or
shrinking societies have been down at heel.

Partisans of one scenario shrug off the challenges of the other,
expressing "confidence" that they can be handled without actually
doing much to ensure that they are. Once you blow away the fog of
ideology, the outlines of a comprehensive action plan begin to emerge.
It is hardly the only way forward, but it can serve as a starting
point for discussion.

A recurring theme of this plan is that business is not necessarily the
enemy of nature, or vice versa. Traditionally the economy and
environment have not even been described in like terms. The most-
watched economic statistics, such as gross domestic product (GDP), do
not measure resource depletion; they are essentially measures of cash
flow rather than balance sheets of assets and liabilities. If you
clear-cut a forest, GDP jumps even though you have wiped out an asset
that could have brought in a steady stream of income.

More broadly, the prices we pay for goods and services seldom include
the associated environmental costs. Someone else picks up the tab--and
that someone is usually us, in another guise. By one estimate, the
average American taxpayer forks out $2,000 a year to subsidize
farming, driving, mining and other activities with a heavy
environmental footprint. The distorted market gives consumers and
producers little incentive to clean up. Environmentalists
inadvertently reinforce this tendency when they focus on the priceless
attractions of nature, which are deeply meaningful but difficult to
weigh against more pressing concerns. The Endangered Species Act has
provided iconic examples of advocates talking past one another. Greens
blamed the plight of spotted owls on loggers; the loggers blamed
unemployment on self-indulgent ornithology. In fact, both were victims
of unsustainable forestry.

In recent years, economists and environmental scientists have come
together to hang a price tag on nature's benefits. Far from demeaning
nature, this exercise reveals how much we depend on it. The Millennium
Ecosystem Assessment, published earlier this year, identified services
-- from pollination to water filtration -- that humans would have to
provide for themselves, at great cost, if nature did not. Of the 24
broad categories of services, the team found that 15 are being used
faster than they regenerate.

When the environment is properly accounted for, what is good for
nature is often what is good for the economy and even for individual
business sectors. Fishers, for example, maximize their profits when
they harvest fisheries at a sustainable level; beyond that point, both
yields and profits decline as more people chase ever fewer fish. To be
sure, life is not always so convenient. Society must sometimes make
real trade-offs. But it is only beginning to explore the win-win

If decision makers can get the framework right, the future of humanity
will be secured by thousands of mundane decisions: how many babies
people have, where they graze their cattle, how they insulate their
houses. It is usually in mundane matters that the most profound
advances are made. What makes a community rich is not the computers
and the DVDs, which you can find nowadays even in humble villages. It
is the sewage pipes, the soft beds, the sense of physical and economic
security. By helping to bring these benefits of modernity to all,
science and technology will have done something more spectacular than
building space colonies.

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