Today 7:44 PM ET (Dow Jones)
By Matt Ridley
How many times have you heard that we humans are "using up" the
world's resources, "running out" of oil, "reaching the limits" of the
atmosphere's capacity to cope with pollution or "approaching the
carrying capacity" of the land's ability to support a greater
population? The assumption behind all such statements is that there is a
fixed amount of stuff--metals, oil, clean air, land--and that we risk
exhausting it through our consumption.
"We are using 50%
more resources than the Earth can sustainably produce, and unless we
change course, that number will grow fast--by 2030, even two planets
will not be enough," says Jim Leape, director general of the World Wide
Fund for Nature International (formerly the World Wildlife Fund).
But here's a peculiar feature of human history: We burst through
such limits again and again. After all, as a Saudi oil minister once
said, the Stone Age didn't end for lack of stone. Ecologists call this
"niche construction"--that people (and indeed some other animals) can
create new opportunities for themselves by making their habitats more
productive in some way. Agriculture is the classic example of niche
construction: We stopped relying on nature's bounty and substituted an
artificial and much larger bounty.
Economists call the same
phenomenon innovation. What frustrates them about ecologists is the
latter's tendency to think in terms of static limits. Ecologists can't
seem to see that when whale oil starts to run out, petroleum is
discovered, or that when farm yields flatten, fertilizer comes along, or
that when glass fiber is invented, demand for copper falls.
That frustration is heartily reciprocated. Ecologists think that
economists espouse a sort of superstitious magic called "markets" or
"prices" to avoid confronting the reality of limits to growth. The
easiest way to raise a cheer in a conference of ecologists is to make a
rude joke about economists.
I have lived among both tribes. I
studied various forms of ecology in an academic setting for seven years
and then worked at the Economist magazine for eight years. When I was
an ecologist (in the academic sense of the word, not the political one,
though I also had antinuclear stickers on my car), I very much espoused
the carrying-capacity viewpoint--that there were limits to growth. I
nowadays lean to the view that there are no limits because we can invent
new ways of doing more with less.
This disagreement goes to
the heart of many current political issues and explains much about why
people disagree about environmental policy. In the climate debate, for
example, pessimists see a limit to the atmosphere's capacity to cope
with extra carbon dioxide without rapid warming. So a continuing
increase in emissions if economic growth continues will eventually
accelerate warming to dangerous rates. But optimists see economic growth
leading to technological change that would result in the use of
lower-carbon energy. That would allow warming to level off long before
it does much harm.
It is striking, for example, that the
Intergovernmental Panel on Climate Change's recent forecast that
temperatures would rise by 3.7 to 4.8 degrees Celsius compared with
preindustrial levels by 2100 was based on several assumptions: little
technological change, an end to the 50-year fall in population growth
rates, a tripling (only) of per capita income and not much improvement
in the energy efficiency of the economy. Basically, that would mean a
world much like today's but with lots more people burning lots more coal
and oil, leading to an increase in emissions. Most economists expect a
five- or tenfold increase in income, huge changes in technology and an
end to population growth by 2100: not so many more people needing much
less carbon.
In 1679, Antonie van Leeuwenhoek, the great
Dutch microscopist, estimated that the planet could hold 13.4 billion
people, a number that most demographers think we may never reach. Since
then, estimates have bounced around between 1 billion and 100 billion,
with no sign of converging on an agreed figure.
Economists
point out that we keep improving the productivity of each acre of land
by applying fertilizer, mechanization, pesticides and irrigation.
Further innovation is bound to shift the ceiling upward. Jesse Ausubel
at Rockefeller University calculates that the amount of land required to
grow a given quantity of food has fallen by 65% over the past 50 years,
world-wide.
Ecologists object that these innovations rely
on nonrenewable resources, such as oil and gas, or renewable ones that
are being used up faster than they are replenished, such as aquifers. So
current yields cannot be maintained, let alone improved.
In
his recent book "The View from Lazy Point," the ecologist Carl Safina
estimates that if everybody had the living standards of Americans, we
would need 2.5 Earths because the world's agricultural land just
couldn't grow enough food for more than 2.5 billion people at that level
of consumption. Harvard emeritus professor E.O. Wilson, one of
ecology's patriarchs, reckoned that only if we all turned vegetarian
could the world's farms grow enough food to support 10 billion people.
Economists respond by saying that since large parts of the world,
especially in Africa, have yet to gain access to fertilizer and modern
farming techniques, there is no reason to think that the global land
requirements for a given amount of food will cease shrinking any time
soon. Indeed, Mr. Ausubel, together with his colleagues Iddo Wernick and
Paul Waggoner, came to the startling conclusion that, even with
generous assumptions about population growth and growing affluence
leading to greater demand for meat and other luxuries, and with
ungenerous assumptions about future global yield improvements, we will
need less farmland in 2050 than we needed in 2000. (So long, that is, as
we don't grow more biofuels on land that could be growing food.)
But surely intensification of yields depends on inputs that may run
out? Take water, a commodity that limits the production of food in many
places. Estimates made in the 1960s and 1970s of water demand by the
year 2000 proved grossly overestimated: The world used half as much
water as experts had projected 30 years before.
The reason
was greater economy in the use of water by new irrigation techniques.
Some countries, such as Israel and Cyprus, have cut water use for
irrigation through the use of drip irrigation. Combine these
improvements with solar-driven desalination of seawater world-wide, and
it is highly unlikely that fresh water will limit human population.
The best-selling book "Limits to Growth," published in 1972 by the
Club of Rome (an influential global think tank), argued that we would
have bumped our heads against all sorts of ceilings by now, running
short of various metals, fuels, minerals and space. Why did it not
happen? In a word, technology: better mining techniques, more frugal use
of materials, and if scarcity causes price increases, substitution by
cheaper material. We use 100 times thinner gold plating on computer
connectors than we did 40 years ago. The steel content of cars and
buildings keeps on falling.
Until about 10 years ago, it was
reasonable to expect that natural gas might run out in a few short
decades and oil soon thereafter. If that were to happen, agricultural
yields would plummet, and the world would be faced with a stark dilemma:
Plow up all the remaining rain forest to grow food, or starve.
But thanks to fracking and the shale revolution, peak oil and gas
have been postponed. They will run out one day, but only in the sense
that you will run out of Atlantic Ocean one day if you take a rowboat
west out of a harbor in Ireland. Just as you are likely to stop rowing
long before you bump into Newfoundland, so we may well find cheap
substitutes for fossil fuels long before they run out.
The
economist and metals dealer Tim Worstall gives the example of tellurium,
a key ingredient of some kinds of solar panels. Tellurium is one of the
rarest elements in the Earth's crust--one atom per billion. Will it
soon run out? Mr. Worstall estimates that there are 120 million tons of
it, or a million years' supply altogether. It is sufficiently
concentrated in the residues from refining copper ores, called copper
slimes, to be worth extracting for a very long time to come. One day, it
will also be recycled as old solar panels get cannibalized to make new
ones.
Or take phosphorus, an element vital to agricultural
fertility. The richest phosphate mines, such as on the island of Nauru
in the South Pacific, are all but exhausted. Does that mean the world is
running out? No: There are extensive lower grade deposits, and if we
get desperate, all the phosphorus atoms put into the ground over past
centuries still exist, especially in the mud of estuaries. It's just a
matter of concentrating them again.
In 1972, the ecologist
Paul Ehrlich of Stanford University came up with a simple formula called
IPAT, which stated that the impact of humankind was equal to population
multiplied by affluence multiplied again by technology. In other words,
the damage done to Earth increases the more people there are, the
richer they get and the more technology they have.
Many
ecologists still subscribe to this doctrine, which has attained the
status of holy writ in ecology. But the past 40 years haven't been kind
to it. In many respects, greater affluence and new technology have led
to less human impact on the planet, not more. Richer people with new
technologies tend not to collect firewood and bushmeat from natural
forests; instead, they use electricity and farmed chicken--both of which
need much less land. In 2006, Mr. Ausubel calculated that no country
with a GDP per head greater than $4,600 has a falling stock of forest
(in density as well as in acreage).
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April 25, 2014 19:44 ET (23:44 GMT)
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