TOO MANY RICH PEOPLE:
Weighing Relative Burdens on the Planet
INTERNATIONAL CONFERENCE ON POPULATION AND DEVELOPMENT
Cairo, 5 - 13 September 1994
by Paul Ehrlich
Concern
about population problems among citizens of rich countries generally focuses on
rapid population growth in most poor nations. But the impact of humanity on
Earth's life support systems is not just determined by the number of people
alive on the planet. It also depends on how those people behave. When this is
considered, an entirely different picture emerges: the main population problem
is in wealthy countries. There are, in fact, too many rich people.
The
amount of resources each person consumes, and the damage done by the
technologies used to supply them, need to be taken as much into account as the
size of the population. In theory, the three factors should be multiplied
together to obtain an accurate measurement of the impact on the planet*.
Unhappily, Governments do not keep statistics that allow the consumption and
technology factors to be readily measured—so scientists substitute per capita
energy consumption to give a measure of the effect each person has on the
environment.
USING
AND CONSUMING This makes sense. All human activities require the use of energy,
and the most environmentally destructive of those activities for the most part
require a great deal of it. Human beings use energy to obtain resources,
process them into useful items, and then use or consume them. At every step,
environmental damage is done.
In
traditional societies—more or less in balance with their environments —that
damage may be self-repairing. Wood cut for fires or structures regrows, soaking
up the carbon dioxide produced when it was burned. Water extracted from streams
is replaced by rainfall. Soils in fields are regenerated with the help of crop
residues and animal manures. Wastes are broken down and reconverted into
nutrients by the decomposer organisms of natural ecosystems.
At
the other end of the spectrum, paving over fields and forests with concrete and
asphalt, mining the coal and iron necessary for steel production with all its
associated land degradation, and building and operating automobiles, trains and
aeroplanes that spew pollutants into the atmosphere, are all energy-intensive
processes. So are drilling for and transporting oil and gas, producing
plastics, manufacturing chemicals (from DDT and synthetic nitrogen fertilizers
to chlorofluorocarbons and laundry detergents) and building power plants and
dams. Industrialized agriculture uses enormous amounts of energy—for ploughing,
planting, fertilizing and controlling weeds and insect pests and for
harvesting, processing, shipping, packing, storing and selling foods. So does
industrialized forestry for timber and paper production.
PAYING
THE PRICE Incidents such as Chernobyl and oil spills are among the
environmental prices paid for mobilizing commercial energy—and soil erosion,
desertification, acid rain, global warming, destruction of the ozone layer and
the toxification of the entire planet are among the costs of using it.
In
all, humanity's high-energy activities amount to a large-scale attack on the
integrity of Earth's ecosystems and the critical services they provide. These
include control of the mix of gases in the atmosphere (and thus of the
climate); running of the hydrologic cycle which brings us dependable flows of
fresh water; generation and maintenance of fertile soils; disposal of wastes;
recycling of the nutrients essential to agriculture and forestry; control of
the vast majority of potential crop pests; pollination of many crops; provision
of food from the sea; and maintenance of a vast genetic library from which
humanity has already withdrawn the very basis of civilization in the form of
crops and domestic animals.
THE
RELATIVE IMPACT The average rich-nation citizen used 7.4 kilowatts (kW) of
energy in 1990—a continuous flow of energy equivalent to that powering 74
100-watt lightbulbs. The average citizen of a poor nation, by contrast, used
only 1 kW. There were 1.2 billion people in the rich nations, so their total
environmental impact, as measured by energy use, was 1.2 billion x 7.4 kW, or
8.9 terawatts (TW)—8.9 trillion watts. Some 4.1 billion people lived in poor
nations in 1990, hence their total impact (at 1 kW a head) was 4.1 TW.
The
relatively small population of rich people therefore accounts for roughly
two-thirds of global environmental destruction, as measured by energy use. From
this perspective, the most important population problem is overpopulation in
the industrialized nations.
The
United States poses the most serious threat of all to human life support systems.
It has a gigantic population, the third largest on Earth, more than a quarter
of a billion people. Americans are superconsumers, and use inefficient
technologies to feed their appetites. Each, on average, uses 11 kW of energy,
twice as much as the average Japanese, more than three times as much as the
average Spaniard, and over 100 times as much as an average Bangladeshi.
Clearly, achieving an average family size of 1.5 children in the United States
(which would still be larger than the 1.3 child average in Spain) would benefit
the world much more than a similar success in Bangladesh.
CLOSING
THE GAP Professor John P. Holdren of the University of California has generated
an "optimistic" scenario for solving the population-
resource-environment predicament. This envisages population growth halted at 10
billion a century from now, and rich nations reducing their energy consumption
to 3 kW a head. His population target is feasible with modest effort, and the
reduction in energy consumption could be achieved with technologies already in
hand—given the necessary political will—and would produce an increase in the
quality of life. This would provide room for needed economic growth in poor
nations, which could triple their per-person energy use to 3 kW. Thus the gap
between rich and poor nations would be closed, while the total world impact
would increase from 13 TW to 30 TW (10 billion x 3 kW).
Will
the environment a century hence be able to support 2.3 times as much activity
as today? It's questionable, but perhaps with care it could, at least
temporarily. Success would require a degree of cooperation, care for our fellow
human beings, and respect for the environment that are nowhere evident now. But
society has shown it can change rapidly when the time is ripe; let us hope that
the United Nations International Conference on Population and Development will
help ripen the time.
*
* *
*
The relationship is summarized in the classic I=PAT identity: Impact is equal
to Population size, multiplied by per capita consumption (Affluence), in turn
multiplied by a measure of the damage done by the Technologies chosen to supply
each unit of consumption.
Mr.
Paul R. Ehrlich is Bing Professor of Population Studies and Professor of
Biological Sciences at Stanford University in the United States. His most
recent books, both co-authored with his wife Anne, are "The Population
Explosion" (Simon and Schuster, 1990) and "Healing the Planet"
(Addison-Wesley, 1991). The feature originally appeared in Vol. 6, No.3, 1994
of "Our Planet". The views expressed herein do not necessarily
reflect those of UNEP.
UNEP
Feature 1994/8
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