Ecologists worry that the world's resources come in fixed amounts that will run out, but we have broken through such limits again and again
""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."
"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."
"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."
"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,"
"the ecologist
Carl Safina
estimates that if everybody had the living standards of Americans, we would need 2.5 Earths"
"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."
"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."
"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."
"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."
"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."
"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,"
"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,"
"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."
"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).
Haiti
is 98% deforested and literally brown on satellite images, compared
with its green, well-forested neighbor, the Dominican Republic. The
difference stems from Haiti's poverty, which causes it to rely on
charcoal for domestic and industrial energy, whereas the Dominican
Republic is wealthy enough to use fossil fuels,"
"Water returns to the environment through sewage and can be reused.
Phosphorus gets recycled through compost. Tellurium is in solar panels,
which can be recycled. As the economist Thomas Sowell wrote in his 1980
book "Knowledge and Decisions," "Although we speak loosely of
'production,' man neither creates nor destroys matter, but only
transforms it.""
"A widely used measure of "ecological
footprint" simply assumes that 54% of the acreage we need should be
devoted to "carbon uptake."
But what if
tree planting wasn't the only way to soak up carbon dioxide? Or if trees
grew faster when irrigated and fertilized so you needed fewer of them?
Or if we cut emissions, as the U.S. has recently done by substituting
gas for coal in electricity generation? Or if we tolerated some increase
in emissions (which are measurably increasing crop yields, by the way)?"
"ecologists have been using "human
appropriation of net primary production"—that is, the percentage of the
world's green vegetation eaten or prevented from growing by us and our
domestic animals—as an indicator of ecological limits to growth. Some
ecologists had begun to argue that we were using half or more of all the
greenery on the planet.
This is wrong,
says Dr. Haberl, for several reasons. First, the amount appropriated is
still fairly low: About 14.2% is eaten by us and our animals, and an
additional 9.6% is prevented from growing by goats and buildings,
according to his estimates. Second, most economic growth happens without
any greater use of biomass. Indeed, human appropriation usually
declines as a country industrializes and the harvest grows—as a result
of agricultural intensification rather than through plowing more land.
Finally,
human activities actually increase the production of green vegetation
in natural ecosystems. Fertilizer taken up by crops is carried into
forests and rivers by wild birds and animals, where it boosts yields of
wild vegetation too (sometimes too much, causing algal blooms in water).
In places like the Nile delta, wild ecosystems are more productive than
they would be without human intervention,"