Can Technology Spare the
Earth?
Evolving efficiencies in our use of
resources suggest that technology
can restore the environment even as population
grows
American Scientist Magazine 84(2):166-178, March-April 1996.
URL: http://phe.rockefeller.edu/sparetheearth/
(NOTE: The color figures are at the end of this document for easier online reading)
Technologies have enabled us to expand our
range and transform the earth. In 1909 Peary sledded to the North Pole, and in
1911 Amundsen reached the South. Improved navigational aids and ships that could
withstand the pack ice made the poles accessible to men and dogs. Less than a
century later we worry about the environmental purity of the polar regions and
the ozone that shields them. My fundamental question is whether the technology
that has conquered the earth can also spare it. To answer this question, I shall
examine secular trends in what technology does with four paramount resources:
energy, materials, land and water. I focus on the evolving efficiency of use of
these resources. Economists call such resources "factors of production," along
with labor and capital. Customarily, technology's relation to environment is
considered by evaluating lists of devices and machines: cars, oil tankers,
nuclear power stations, windmills, wastewater-treatment plants, spray cans and
chain saws. My approach is more basic. I ask whether technology enables us to
obtain services more efficiently and, if so, at what rates. The answers indicate
the feasibility of greatly diminishing our environmental burdens by increasing
the productivity of our resources. Analysts, eager to assimilate the latest
information, live life on the tangent, extrapolating brief fluctuations to
eternity. To counter this tendency, I search for stable signals amid the noise
of the daily news. The historical analyses shared here, many contributed to an
ongoing project at The Rockefeller University on technological trajectories and
the human environment, seek the inherent lifetimes of processes of technological
development, which can extend generations and centuries. Recognizing and
formally analyzing incomplete developmental processes and the rhythmic patterns
of processes permits confident prediction. Identifying secular trends also
enables me to frame answers to a second question: what distinguishes the last
half-century or so with regard to environment and technology. The years around
1970 marked the maximum rate of growth of human population in modern times. Have
we more generally passed a point of inflection in the curve of human
development? Finally, what present actions will wave us toward sweet, greener
days? Two basic arguments weigh against technology. One is that technology's
success is self-defeating. Technology makes the human niche elastic. If we solve
problems, our population grows and creates further, eventually insurmountable
problems. The cardinal case is the conquest of death in developing countries.
Public-health measures and modern medicine defeat mortality, while fertility
declines at a much slower pace, and so population explodes. Before dosing, I
shall consider technology's relation to population. Population is always the
catch. The second argument contra-technology is the paucity of human wisdom.
Technology creates handguns and hydrogen bombs, and these kill. We can use
science and technology to provide goods and services for human sustenance and
comfort and other purposes worthy for the planet. But technology powers good and
evil. Some would feel more comfort with less power. I leave it to others to
discuss the cultural controls to assure constructive use of science and
technology. A subordinate, manageable argument is that unanticipated
consequences of the introduction of technologies diminish their value.
Chlorinated fluorocarbons solved the problem of explosive and inefficient
ammonia based refrigerators, but turned out 40 years after their introduction to
threaten life's stratospheric filter. The appropriate response is a feedback
system: Assess technologies early in their prospective social penetration, watch
them thereafter for surprises and tailor designs to fit changing needs and
tastes. I outline a global picture, with most detail from the United States.
For more than a century the United States has on average adopted technologies
earliest, diffused them fullest and documented the outcomes. The symptoms and
cures show.
Energy
Energy systems extend from the mining of coal through
the generation and transmission of electricity to the artificial light that
enables the reader to see this page. For environmental technologists, two
central questions define the energy system. First, is the efficiency increasing?
Second, is the carbon used to deliver energy to the final user declining?
Energy efficiency has been gaining in many segments,
probably for thousands of years. Think of all the designs and devices to improve
fireplaces and chimneys. Or consider the improvement in motors and lamps (Figure
2). About 1700 the quest began to build efficient engines, at first with steam.
Three hundred years have increased the efficiency of generators from 1 to about
50 percent of the apparent limit, the latter achieved by today's best gas
turbines. Fuel cells can advance efficiency to 70 percent. They will require
about 50 years to do so, if the socio-technical clock continues to tick at its
established rate. In 300 years, physical laws may finally arrest our engine
progress.
Whereas centuries measure the struggle to improve generators, lamps
brighten with each decade. A new design proposes to bombard sulfur with
microwaves. One such bulb the size of a golf ball could purportedly produce the
same amount of light as hundreds of high-intensity mercury-vapor lamps, with a
quality of light comparable to sunlight. The current 100-year pulse of
improvement evident in Figure 2 will surely not extinguish ideas for
illumination The next century may reveal quite new ways to see in the dark For
example, nightglasses, the mirror image of sunglasses, could make the objects of
night visible with a few milliwatts. Segments of the energy economy
have advanced impressively toward local ceilings of 100 percent efficiency.
However, modem economies still work far from the limit of system efficiency
because system efficiency is multiplicative, not additive. In fact, if we define
efficiency as the ratio of the theoretical minimum to the actual energy
consumption for the same goods and services, modern economies probably run at
less than 5 percent efficiency for the full chain from extracting primary energy
to delivery of the service to the final user. So, far from a ceiling, the United
States has averaged about 1 percent less energy to produce a good or service
each year since about 1800. At that pace of advance, total efficiency will still
approach only 15 percent by 2100. Because of some losses difficult to avoid in
each link of the chain, the thermodynamic efficiency of the total system in
practice could probably never exceed 50 percent. Still, in 1995 we are early in
the game. What about the decarbonization of the energy system? Carbon matters
because it blackens lungs, causes air pollution and oil spills and regulates
climate. Carbon is also a surrogate for sulfur, heavy metals and other
environmental bads that attach to it in the dirty fossil fuels. Carbon enters
the energy economy bonded with hydrogen as wood (and other biomass), coal, oil
and natural gas. Per unit of energy, wood weighs most heavily in carbon,
followed by coal, and then oil, with natural gas following as much the
lightest. One can measure decarbonization in several different ways. The
upper graph in Figure 4 shows the changing carbon intensity of primary energy
for the world, where tons of carbon are divided by the total energy produced.
This perspective shows that the long-term rate of decarbonization of the energy
system is about 0.3 percent per year. Plentiful natural gas, efficient turbines
and thrifty end-use devices promise more energy delivered with less carbon
during the next decades. Uranium also decarbonizes. At the end of 1993 432
operating nuclear reactors prodded almost 20 percent of the world's electricity.
Even if a fraction of the 48 listed in 1994 as under construction never operate,
the remainder assure a continuing nuclear contribution to decarbonization. The
radioactive reactor products, which are toxic and also hard and slow to degrade,
and potentially powerful explosives, must of course be safely isolated. Solar
sources also decarbonize but continue to stumble over obstacles in energy
storage and transport. Consider decarbonization also as the diminishing
carbon intensity of the economies of a range of countries. Measured as the ratio
of kilograms of carbon to gross domestic product and taking into account
fuelwood and other renewable sources of energy, the decarbonization of dozens of
nations studied, including Turkey, Thailand and China as well as the United
Kingdom, Germany and Japan, has advanced almost in parallel. Countries begin at
different times from different situations, but once they begin to decarbonize,
they advance at about the same rates, and irreversibly, so far. Between 1970
and 1993, even the gas-guzzling United States more than doubled the ratio of its
income to carbon use, decarbonizing about 3 percent per year. The spectrum of
achievement, from about 3 kilograms of carbon per dollar of output in China to
less than 0.2 in Japan and France, shows the distance most of the world economy
stands from leading practice. The carbon intensity of the Chinese and Indian
economies resembles the Japanese, American and European at the outset of
industrialization in the 19th century. Fundamentally,
decarbonization tracks a technological competition between combustible elements.
In the hydrocarbons, the truly desirable element for energy generation is not
the carbon but the hydrocarbon. The evolution of the atomic ration of hydrogen
to carbon in the world fuel mix displays the gradual and unrelenting penetration
of the energy market by the number one element of the periodic table (Figure
4, bottom). All these analyses imply that during the next 100 years the
human economy will clear most of the carbon from its system and move, via
natural gas, to a hydrogen metabolism, Hydrogen, fortunately, is the immaterial
material. It can be manufactured from something abundant, namely water, it can
substitute for most solid, liquid and gaseous fuels in use, and the product of
its combustion, water vapor, does not pollute. The next decades will see a
vigorous growth in the hydrogen industry. Nightly nuclear heat seeking a market
outlet can efficiently steam-reform natural gas into hydrogen and carbon
dioxide, the latter permanently reinjected into the gas fields from whence it
came. Later, heat, nuclear or solar, can neatly decompose water. Hydrogen,
of course, requires a partner, electricity, to provide action at a distance in a
clean energy system. Since Edison began the commercial industry in the 1880s,
the electrical system has grown in two neat pulses each lasting about 50 years,
synchronized with long cycles of economic growth. A new pulse of growth should
soon begin, in which electricity powers not only more information products but
also more of the transport system, using linear motors. The magnetically
levitated train soon to operate between Hamburg-Berlin inaugurates the
way. Combining analyses of efficiency and decarbonization startles many with
the fact that national energy systems ranging from India to South Korea to
France are heading in the right direction, toward micro-emissions. The way is
long, but we are on the light path.
Land
Of all human activities, agriculture transforms the environment most
widely. Corps and pasture occupy at least one-fifth the land surface, at least
ten times as much as cities, towns and roads. Agriculture has consumed forests,
drained wetlands, erased habitats and favored some plants over others in fierce
green warfare. Farms, of course, also feed us. Yields per hectare measure
the productivity of land and the efficiency of land use. To 1940, yields per
hectare of most crops advanced little, and more mouths required more land to
feed them. During the past half century, ratios of crop to land for the world's
major grains-maize, rice, soybean and wheat have climbed, fast and globally. The
rise in wheat in India, Egypt, Ireland and the U.S. shows the inception and the
spread of the trend (Figure 6, top). A cluster of innovations
including tractors, seeds, chemicals and irrigation, joined through timely
information flows and better organized markets, raised yields to feed billions
more without clearing new fields. In fact, since mid-century global cropland has
remained stable. Expansion in developing countries has offset contraction in
Europe and North America. As the century draws to a close, the earth is at a
historic turning point in land use. The continuing diffusion of high yields and
efficient land use permits the absolute reversal of the destruction of nature
that has occurred for many centuries. Societies chronically fear exhaustion
of the potential to increase food supply. In reality, the agricultural
production frontier is still spacious, even without invoking the engineering of
plants with new molecular techniques. For many decades in Iowa, while yields
have risen steadily, the average corn grower has managed only half the yield of
the Iowa master grower, and the world grows only about 20 percent of the top
Iowa farmer. The production ratio of the performers has not changed much since
1960. In Iowa the average performer lags more than 30 years behind the state of
the art. Even where diffusion proceeds at a moderate pace, the effects
accumulate dramatically. In India, for example, by raising wheat yields farmers
spared 42 million hectares, about the size of Sweden or California, if we
compare the land actually harvested in 1991 with the land the farmers would have
harvested at 1961-66 yield for the actual production. Globally, the land spared
since 1960 by raising yields of grain, which make up more than half of all
calories, equals the Amazon basin (Figure 6, bottom). A single-minded
concentration on land raises concern that side effects will harm the nature we
seek to preserve. In fact, land requires little more clearing, tilling and
cultivating for high yields than for low ones. Protecting lush foliage needs
little more pesticide and usually less herbicide than sparse foliage. Luxuriant
foliage also protects soil better from erosion. The law of diminishing returns
applies to fertilizers, which farmers tend to use abundantly. In many areas
yield gains now come by optimizing inputs such as nitrogen and phosphorus in
step and lowering total application. In sum, careful management of the land we
do use is likely to diminish the total fallout from food production. Most
fallout is coextensive with land used. What is a reasonable outlook for the
land cropped for future population? Future calories per capita will likely lie
between the 3,000 per day of a vegetarian diet and the 6,000 that include meat
(counting dietary calories plus the calories fed to food and draft animals and
not recovered in milk, meet and so on). Let us consider, as Paul Waggoner has
done (Waggoner 1994) how much cropland a population of 10 billion, almost twice
the present, could spare for wilderness or other purposes with that range of
calories per capita. If farmers fail to raise global average yields from the
present 2 tons grain equivalent per hectare, people will have to lower their
daily portions to 3,000 calories to avoid further land clearing. But Irish wheat
and American corn now average 8 tons per hectare. If farmers can lift the global
average to 5,10 billion people on average can enjoy the diet 6,000 calories
bring, and spare a quarter of the present 1.4 billion hectares of
cropland. The quarter spared is about twice the size of Alaska. If future
farmland on average yielded today's U.S. corn, 10 billion eating an American
diet could allow cropland the area of Australia to revert to wilderness. Per
hectare, annual world grain yields in fact rose 2.15 percent 1960-1994. If
dynamics continue as usual, farmers will grow 8 tons per hectare around 2060, at
the end of the decade in which the United Nations projects population to reach
10 billion From the Great Plains of America to the Great Plains of China,
reversion of farms and ranches to woods and grasses will be a spreading, major
environmental feature of the next decades, and beyond. And governments will
avidly seek rationales to subsidize agriculture to keep it from contracting more
rapidly than culture will allow.
Materials
We can reliably project more efficient energy,
decarbonization and effectively landless agriculture. What about a companion
dematerialization? I will define dematerialization primarily as the decline over
time in weight of materials used to perform a given economic function.
Dematerialization would matter enormously for the environment. Excluding
water and oxygen, in 1990 each American mobilized on average about 50 kilograms
per day. Reducing the materials intensity of the economy could preserve
landscapes and natural resources, lessen garbage and reduce human exposures to
hazardous materials. Over time new materials substitute for old. Successful
new materials usually show improved properties per ton, thus leading to a lower
intensity of use for a given task The idea is as old as the epochal succession
from stone to bronze to iron. Our century has witnessed the relative decline of
wood and the traditional metals and the rise of aluminum and especially plastics
(Figure 7, top). Modern examples of dematerialization abound. Since
the early 19th century, the ratio of weight to power in industrial boilers has
decreased almost 100 times. Within the steel industry, powder metallurgy, thin
casting, ion-beam implantation and directional solidification as well as drop
and cold forging have allowed savings up to 50 percent of material inputs in a
few decades. In the 1970s a mundane invention, the radial tire, directly lowered
weight and material by one-quarter below the bias-ply tires they replaced. An
unexpected and bigger gain in efficiency came from the doubling of tire life by
radials, so halving the use of material (and the piles of tire carcasses
blighting landscapes and breeding mosquitoes). Lightweight optical fibers with
30 to 40 times the carrying capacity of conventional wiring and invulnerability
to electromagnetic interference are ousting copper in many segments of the
telecommunications infrastructure. The development of high-fructose corn syrup
(HFCS) in the 1960s eliminated sugar from industrial uses in the United States.
HFCS has five times sugar's sweetening power on a unit-weight basis, with a
proportional impact on agricultural land use. Certainly many products--for
example, cars, computers and containers--have become lighter and often smaller.
Compact discs selling for less than $100 now contain 90 million home phone
numbers of Americans, equivalent to the content of telephone books once costing
$60,000 and weighing 5 tons. At midcentury, glass bottles dominated. In 1953 the
first steel soft-drink can was marketed. Cans of aluminum, one-third the density
of steel, entered the scene a decade later and by 1986 garnered more than 90
percent of the beer and soft-drink market. Between 1973 and 1992 the aluminum
can itself lightened 25 percent. In 1976 polyethylene terephthalate resins began
to win a large share of the market, especially for large containers previously
made of glass. Recycling, of course, diminishes the demand for primary
materials and may thus be considered a form of dematerialization. No longer
limited to resource-poor individuals and regions, during the past couple of
decades recycling has regained standing as a generalized social practice in the
U.S. and other societies with huge material appetites. Difficulties arise in
the more complex "new materials society" in which the premium lies on
sophisticated materials and their applications. Alloys and composites with
attractive structural properties can be hard to separate and recycle. Popular
materials can be lighter but bulkier or more toxic. Reuse of plastics may be
less economical than burning them (cleanly) for fuel or otherwise extracting
their chemical energy. Most important, economic and population growth has
multiplied the volume of products and objects. Thus, total wastes have tended to
increase while declining per unit of economic activity (Figure 7,
bottom). By weight, construction materials make up about 40 percent of
the materials Americans consume and thus form a significant metric. Although
absolute use of physical-structure materials by weight has fluctuated,
consumption per unit of economic activity has trended downward since 1970.
Because energy materials such as petroleum constitute another 40 percent of our
materials diet, increases in energy efficiency could also markedly dematerialize
economies. As yet, trends with respect to dematerialization are equivocal.
Better and more complete data on materialization and dematerialization over long
periods for the United States and the rest of the world need to be assembled and
analyzed. Moreover, the heterogeneity of purpose of materials will never permit
the performance of the materials sector to be summarized as simply as kilowatts
and carbon can summarize energy or tons per hectare summarize land. A kilogram
of iron does not compare with one of arsenic. But the promise dearly exists for
what Robert Frosch, I and our colleagues call a superior "industrial ecology,"
in which the materials intensity of the economy declines, wastes lessen and the
wastes that are created become nutritious in new industrial food
webs.
Water
We can get more value from each unit of energy, land and material. Can we
squeeze more from a drop of water? Total per capita water withdrawals
quadrupled in the United States between 1900 and 1970, and overall personal
consumption increased by one-third between just 1960 and the early 1970s
(Figure 9). However, since 1975, per capita water use has fallen
appreciably, at an annual rate of 1.3 percent. Absolute water withdrawals peaked
about 1980. Industry, alert to technology as well as costs, exemplifies the
progress, although it consumes a small fraction of total water. Total industrial
water withdrawals plateaued a decade earlier than total U.S. withdrawals and
have dropped by one-third, more steeply than the total. More interesting,
industrial withdrawals per unit of GNP (in 1982 dollars) have dropped steadily
since 1940, when 14 gallons of water flowed into each dollar of output. Now the
flow is less than 3 gallons per dollar. The steep decline taps many sectors,
including chemicals, paper, petroleum refining, steel and food processing. After
adjusting for production levels, not only intake but discharges per unit of
production are perhaps one-fifth of what they were 50 years ago. In
manufacturing, technology as well as law and economics have favored frugal water
use. More efficient use of heat and water usually go together, through better
heat exchangers and the recirculation of cooling water. Legislation, such as the
U.S. Clean Water Act of 1972, encouraged reduction of discharges and recycling
and conservation as well as shifts in relative prices. Although water treatment
may cost only about 5 percent of production, wastewater-treatment systems are
expensive capital investments. Despite the gains, the United States is far
from most efficient practice. Water withdrawals for all users in the countries
making up the Organization for Economic Cooperation and Development range
tenfold, with the U.S. and Canada the highest. Allowing for differences in major
uses (irrigation, electrical cooling, industry, public water supply), large
opportunities for reductions remain. In the late 1980s over 90 percent of
measured U.S. hazardous wastes were still wastewaters. In the long run, with
much higher thermodynamic efficiency for all processes, removing impurities to
recycle water will require small amounts of energy. Dialytic membranes open the
way to such efficient purification systems. Because hydrogen will be, with
electricity, the main energy carrier, its combustion (if from seawater) may
eventually provide another important source of fresh water, perhaps 200 liters
per person per day at the level of final consumers, about one-fourth the current
withdrawal in water-prudent societies such as Denmark. Importantly, as
agriculture contracts spatially and irrigates more frugally; its water demand
will shrink.
Population
l have demonstrated a revolution in factor productivity, whether energy,
land, materials or water. The game to get more from less is old. In energy,
global progress is documented for centuries. With land, the Chinese started long
ago, but most of the world began only about 1940. 1940 also appears to have
marked a crossing point for new materials. In water, U.S. industry joined the
search about 1940, and the population more generally about 1970. The catch
for homo faber is that our technology not only spares resources but also
expands our niche. Technology further adds to population by increasing longevity
and decreasing mortality. Although fertility has also declined greatly; the role
of new birth-control technologies in the decline has been small. Feedbacks may
well also occur between population growth and density on the one hand and
invention and innovation on the other. Population provides a multiplier that
determines total consumption. So far I have stressed ratios, not
absolutes. To see graphically how technology can change carrying capacity,
consider the population history of Japan. From the establishment of the Tokugawa
Shogunate about 1600 Japan insulated itself from outside technology until 1854
when American Commodore Matthew Perry reopened trade. In 1868 the Meiji
restoration lessened the isolationist policy of the former imperial party, and
Japan entered a period of great borrowing from the Occident. As evident in
Figure 10, Japanese population growth since 1100 sorts perfectly into two pulses
of growth. Tokugawa technology (and culture) and its medieval predecessors
accommodated a gradual addition of 28 million over about five centuries to
Japan's earlier population of about 5 million. Meiji and Western technology
keyed the opening of the niche to another 100 million or so in one
century. Reasoning about the link between technology and carrying capacity
from the Japanese case, my colleague Perrin Meyer and I have speculated about
the growth of the population of the U.S. We hypothesize a sequence of
overlapping pulses of population growth centered on times of rapid economic
expansion, the midpoints of tentatively identified 50-yearlong waves of economic
growth. Technological innovations affecting resources, processes and products
cluster in each economic wave and expand carrying capacity. The first pulse of
population growth associates with wood, iron, steam, canals, and wool and cotton
textiles; the second with coal, steel, railways, telegraphy and early
electrification, and the third with oil, plastics, autos, widespread
electrification, telephony, computers and pharmaceuticals. The fourth, emerging
pulse revolves around natural gas, aviation and a host of information and
molecular technologies. Daring to extrapolate our reasoning with a
"superlogistic" curve using the center points of the growth pulses as the base
points, we find the U.S. population saturating around 400 million in 2100, a
total consistent with projections made by conventional demographic
methods. Clearly the limits to human numbers keep shifting. In any case,
analysis of historic population data shows that the global rate of growth peaked
at about 2.1 percent per year around 1970, as noted near the outset of this
article. Fertility rates, the key factor, have been falling in most nations and
are below the levels needed to replace current population in Europe and Japan.
The difficulty is that we have no logic to predict future fertility, and simply
fitting an equation, as we did for the U.S., is chancy. Globally, the pervasive
economic and social effects of the information revolution could allow the
increase in human numbers to 15 or 50 or 100 billion, or influence the fertile
to choose not to reproduce. The question of future population appears quite
open, as reflected in the spray of projections.
Conclusion
Population frames the challenge for green technologists. To maintain
current levels of cleanliness with the 50 percent increase in population I think
likely for the United States and the current level and kind of economic
activity, emissions per unit of activity would need to drop by one-third. That
is an easy target. An improvement of 1.5 percent per year reaches the target by
2020, 80 years early. The challenge is much harder taking into account
growing consumption. If economic activity doubles per capita roughly every 30
years, as it has since about 1800 in the industrialized countries, the result is
an eightfold increase by 2100. Multiplied by population, the United States would
have 12 times today's emissions and demands on resources, other things being
equal. This scenario of the "dirty dozen" requires micro- or zero emissions per
unit of economic activity to maintain or enhance environmental quality In other
words, Americans need to clean processes by more than one order of magnitude.
More reassuringly, the annual cleaning need be about 2.5 percent. In Europe
and Japan population is stable or even shrinking, easing the magnitude of their
environ mental challenges. The rest of the world, where most people live, faces
the twin pressures of enlarging economies and populations. So in absolute terms
the technical gains must be enormous. But we have seen the outlines of how
the gains can be made. In the long run, we need a smoke free system of
generating hydrogen and electricity that is highly efficient from generator to
consumer, food decoupled from acreage, materials smartly designed and selected
for their uses and recycled, and carefully channeled water. In short, we need a
lean, dry, light economy. In truth, I exaggerate the challenge. With respect
to consumption, multiplying income will not cause an American to eat twice as
much as today in 2020 or eight times more in 2100, and even a mouth moving today
from Lima to Los Angeles only triples its original caloric intake. With respect
to production, history shows that the economy can grow from epoch to epoch only
according to a new industrial paradigm, not by inflating the old. High
environmental performance forms an integral part of the modern paradigm of total
quality. The past half-century signals the preferred directions: the changeover
from oil to gas, the contraction of crops in favor of land for nature, the
development of a new ecology of materials use in industry, and diffusion of more
efficient water use to farmers and residents as well as
industries. Economists always worry about trading off benefits in one area
for costs in another. Hearteningly, we have seen that in general efficiency in
energy favors efficiency in materials; efficiency in materials favors efficiency
in land; efficiency in land favors efficiency in water; and efficiency in water
favors efficiency in energy. The technologies that will thrive, such as
electricity, will concert higher resource productivity. Prone to fail is a
technology, such as biomass farming for energy, which brings into conflict the
goal to spare land with the goal to spare carbon. Some worry that the supply
of a fifth major resource, ingenuity, will run short. But nowhere do averages
appear near the frontier of current best practice. Simply diffusing what we know
can bring gains for several decades. Moreover, science and technology are young.
Aggressively organized research and development (R&D) is another innovation
of the past 50 years. Many industries have systematized their search for better
practice ("endogenized R&D" in the economics jargon) and have the
productivity gains to show for it. Other industries, including much of the
service sector which now forms the bulk of modern economies, and the enlarging
public and non-profit sectors have improved slowly. Overall, society hardly
glimpses the theoretical limits of performance. Inevitably, sectors and
societies will advance at unequal pace. We will continue to have laggards as
well as pioneers. Problems will arise from the distribution of goods, the
actions and interactions of bads, shocking and poorly tailored innovations, and
social traps such as the well-known "tragedy of the commons," which today sadly
entangles the wild stocks of fish. Yet the long history of technical progress
and its reach into more sectors during recent decades encourage. Perhaps the
first Earth Day in 1970 was an inflection point. Policy can interfere
wastefully with dynamics-as-usual, where they are benign. For example,
decarbonization mandates the phasing out of the coal industry worldwide over the
next decades; the political system might prudently assist those who lose their
livelihoods, but not with dollars for actual coal. Wise policy favors science,
experimentation and fluidity, while addressing inequity and insecurity and
insuring against catastrophe. Families named Smith, Cooper, and Miller people
our nation because until not long ago most of us beat metal, bent casks, and
ground grain. Now few workers hold such jobs. So far, except in video, we are
not named Programmer, Sub-Micron, and Genesplicer. We easily forget how much the
modem world has changed and yet how early our day is. We forget the power of
compounding our technical progress, even at one or two percent per year.
Knowledge can grow faster than population and provide abundant green goods and
services. The message from history is that technology, wisely used, can spare
the earth. You can click on it.
Acknowledgments
The author thanks Arnold Grübler, Raphael Kasper, Robert Kates,
Alan McGowan, Perrin Meyer, Nebojsa Nakicenovic, Donald Rogich, Paul Waggoner
and Iddo Wernick.
FIGURES
Figure 1. Advances in technology enable people to obtain services more
efficiently. Greater efficiency in our use of energy, materials, land and water
could help diminish the burdens people place on the environment. One possible
future is captured by the vision of the "buffalo commons": jobs would
concentrate in urban areas (as, for example, at busy Dallas-Forth Worth Airport,
above, where 37,000 people work) as vast lands in the interior of North
America return to a wild state. Restoration of tall grass prairie in the
Midwest, as at the Konza Prairie Research Natural Area in Kansas (also above), has
been guided by conservation organizations and will accelerated as highly
productive agriculture frees additional land. (Above photograph courtesy of
Dallas Fort Worth Airport.)
Figure 2. Energy efficiency is a tern of
modern invention, but the efficiency of energy-conversion technologies has been
increasing for hundreds and probably thousands of years. Improvements in motors
and lamps are analyzed here as a logistic (sigmoid) growth process with a linear
transform that normalizes the data to ease comparison. (From Ausubel and
Marchetti, in press.)
Figure 3. Decarbonization of the world's energy
mix moves the economy from dependence on carbon-heavy fuels, responsible for
black lung, oil spills and large releases of climate-changing greenhouse gases.
A power station in Bitterfeld, Germany (kft), burned lignite, or "brown
coal," contributing to Eastern Europe's severe air-pollution problem. The author
envisions a cleaner energy economy based on hydrogen, whose combustion produces
water vapor. At right a California plant produces hydrogen by steam reforming of
natural gas. (Right photograph courtesy of Air Products and Chemicals,
Inc.)
Figure 4. World primary energy sources have declined in carbon
intensity since 1860. The evolution is seen in the ratio of hydrogen (H) to
carbon © in the world fuel mix, graphed on a logarithmic scale, analyzed as
a logistic growth process and plotted in the linear transform of the logistic
curve (left). After Marchetti 1985). Wood has an effective
hydrogen-to-carbon ratio of 0.1, coal 1, oil 2, and natural gas 4. Progession of
the ratio above natural gas (methane, CH4) requires production of
large amounts of hydrogen fuel without fossil energy. Carbon intensity can also
be calculated as the ratio of the sum of the carbon content of all fuels to the
sum of the energy content of all primary energy sources (right). For such
a calculation carbon emission in tons per kilowatt-year average: wood, 0.84,
coal, 0.73; oil 0.55; and gas, 0.44. (From Nakicenovic, in press).
Figure 5. Much American land cleared by early settlers has reverted to
nature as a result of changes closely related to technological progress and the
increasing ability to grow more crops per acre. As better transport and
machines made farming the rich soils of the Midwest highly profitable, New
England farmers abandoned the rocky fields they had cleared. Dioramas on
display at the Harvard Forest in Petersham, Mass., document the return of New
England to forest. This pair shows the landscape around Petersham in 1830, at
the height of cultivation, and a century later, when volunteer pines and the
maturing hardwoods that followed them filled the landscape. (Photographs
courtesy of the Fisher Museum at Harvard Forest.)
Figure 6. Rising
yields of wheat on four continents (top) illustrate progress in agricultural
productivity. Improved yields have allowed the global area actually harvested
for grain to remain stable at around 600 million hectares (bottom). "Land
spared" is the amount of land that would have been needed to produce actual
grain crops with the 1960 average yield. (Data from Mitchell 1980, Yearbooks of
the Food and Agriculture Organization and the U.S. Department of Agriculture's
"PS&D View," a database.)
Figure 7. Countervailing trends can be detected in the use of materials in
the US. In the top graph, production data are divided by the Gross National
Product in constant (1982) dollars and normalized to 1940. The use of heavy
materials such as steel has been supplanted in the economy by lighter materials,
especially plastics. Since 1970 even aluminum and the agricultural minerals,
phosphates and potash, have declined in relative use. Municipal solid-waste
generation, however, has grown steadily on a per capita basis. In relation to
GNP, solid-waste generation dropped 1960-19185 but climbed again recently. (From
Wernick et al., in press. Data from U.S. Bureau of the Census 1975 and 1993;
U.S. Environmental Protection Agency 1992.)
 Figure 8. Auto manaufacturing today uses plastics and lightweight metals,
exemplifying dematerialization, the trend toward higher materials and products
per unit of economic activity. A Chrysler demonstration car, the Neon Lite,
includes a lightweight instrument panel made of magnesium (left). Yet
total wastes have risen in the U.S. with economic and population growth. At
right, crushed automobiles pile high at a Philadelphia scrap-metal reclamation
center. (Left photograph courtesy of Chrysler Corporation.)
Figure 9.
Total per capita water withdrawals quadrupled in the U.S. between 1900 and 1970,
and overall personal consumption (right) increased by one-third between
1960 and the early 1970s. Since 1975, however, per capita water use has fallen
annually 1.3 percent. Industrial withdrawals per unit of GNP have dropped
steadily since 1940, encouraged by technology as well as law and economics.
Data from other nations show that the U.S. is far from most efficient practice.
(Data from U.S. Bureau of the Census 1975 and 1993.)
Figure 10. History
of Japanese population growth shows how technology changes carrying capacity.
Under the Tokugawa Shogunate from about 1600 to 1854, Japan insulated itself
from outside technology. The right-hand graph decomposes the population data
into a pair of logistic growth pulses in linear form. The pulse the Tokugawa
Shoguns took to its culmination was centered in 1537, required 516 years to grow
from 10 percent to 90 percent of its extent, and saturated at 28 million people
(on top of a pre-existing level of 5 million). The Meiji pulse, centered in
1950, required 95 years, and is saturating now with an addition of 103 million.
(Meyer 1994. Data from Tsuneta Yano Memorial Society 1993 and Taeuber
1958.)
Figure 11. Growing consumption raises the challenge of saving resources
through technology. Since about 1800 in industrialized countries, economic
activity has doubled per capita roughly every 30 years. The contrast between
consumption in developed and developing countries is illustrated by the
“global family portrait” developed by the Material World project,
which photographed typical families with their possessions around the world.
Shown here are the Skeen family of Pearland, Texas, and the Yadev family of
Ahraura, India. (From Material World, Sierra Club Books 1994.)
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Daedalus 125(3):171-198. Jesse H. Ausubel is director of the Program for the Human
Environment and Senior Research Associate at The Rockefeller University and a
program officer of the Alfred P. Sloan Foundation in New York City. From 1977 to
1988, he was associated with the National Academy complex in Washington as a
fellow of the National Academy of Sciences, then as a staff officer with the
National Research Council Board on Atmospheric Sciences and Climate, and finally
as director of programs for the National Academy of Engineering, where he
developed and oversaw studies on the performance of technology-intensive sectors
of U.S. industry and on the diffusion and globalization of technology. In recent
years, he has helped originate industrial ecology, the study of the networks of
flows of materials and energy in industry. Educated at Harvard and Columbia,
Ausubel served on the U.S. Environmental Protection Agency's Science Advisory
Board. Address: Program for the Human Environment, The Rockefeller University,
1230 York Avenue, Box 234, New York, NY 10021-6399. Internet:
phe@mail.rockefeller.edu.
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