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A Changing Relationship
Human beings are just one of the many species that take part in the various natural processes that make up the biosphere. Unlike other species, however, our role in these processes has changed dramatically over time. This section describes the changing relationship between humans and the environment, with particular emphasis upon the impact of the human species on the biosphere.
Q2.68
Is the human species different from the rest of the world's
species? Biologically we are but one species among many. Like all species, we
have always interacted with our environment and, in the process, shaped it to
some extent. Since ancient times the use of fire has altered flora and fauna;
farmers have cut forests and spread certain species of domesticated animals.
Early civilizations even transformed deserts through irrigation. The
environmental impact of humans, however, unlike that of other species, has
increased greatly over time. Although just one part of the global ecosystem, we
are unique in the extent to which we are able to transform it for better or for
worse.
Q2.69
How has our impact on our environment changed? The
environmental impact of the human species has grown in scale, become more rapid,
and changed in character. Whereas we once transformed locales or regions, today
we can be said to be transforming the Earth on a global scale. Changes which
once took decades or centuries are now taking place over the course of a few
years. And whereas we once changed the Earth in relatively small ways (e.g., by
clearing a field of forest cover), we are now able to substantially alter the
flows of elements and energy that constitute the planet's basic life-support
systems.
Q2.70
Are there ways to gauge the scale at which human activity
affects the environment? Yes. In the past, human societies transformed tiny
amounts of energy and materials compared to the cycles of nature. Today,
however, humans transform for their use almost half of the plant material that
the process of photosynthesis creates on the Earth's surface. Primarily as a
result of fertilization, we 'fix' almost as much nitrogen in the environment as
does nature (for an explanation of nitrogen fixation, see question #2.37 in the
chapter on element cycles). And we are currently putting about seven to eight
billion tons of carbon dioxide into the atmosphere per year. This represents
about 7% of the total natural carbon exchange between atmosphere and oceans.
When human activities reach this size they can seriously disrupt not only local
ecosystems but the life-support systems of the biosphere itself.
Q2.71
What has caused the increase in the environmental impact of
our species? There are a number of reasons why humans have had such a great
effect on the Earth, but the three most important factors have probably been
technological advance, economic development, and population growth.
Rapid population growth combined with the development of fossil-fuel-based industrial societies fundamentally changed the scale, speed, and nature of the environmental impact of our species.
Q2.72
Have the results of these changes been positive or negative?
The results have been mixed. On the one hand, there has been a marked increased
in human welfare. On average, the world's population is healthier and better fed
than in previous centuries, although poverty, disease, and starvation have not
been eliminated. On the other hand, the unintended consequence of many of our
activities (especially in the last 200 years) has been environmental
degradation. It has taken us some time to realize that our special abilities, if
not properly managed, can pose a threat to the Earth and to ourselves.
Q2.73
What human activities have had the greatest impact on our
environment? Agriculture, energy use, and manufacturing are the three activities
that have probably had the greatest impact on our environment over the course of
human history.
Q2.74
How recent is this increase in impact? Although human
activity has always had an impact on the environment, most global environmental
change is relatively recent. It has been estimated that in most cases of global
environmental transformation the same amount of change (or more) has occurred in
the last 40 years as occurred in the rest of human history.
Q2.75
Is this human-caused transformation of our environment
increasing or decreasing? Some environmental changes are increasing; others,
however, are decreasing. Deforestation and soil erosion, for example, are
long-established and accelerating types of environmental transformation. Loss of
biodiversity, withdrawal of water from the water cycle, and human alteration of
the element cycles are also increasing, but are more recent in origin. On the
other hand, the extinction of terrestrial vertebrates and marine mammals due to
human activity is slowing. Releases of lead, radioactive material, and some
organic solvents are all decreasing.
Q2.76
Are these changes taking place everywhere to the same extent?
No. Different parts of the globe suffer from these various environmental
problems to different extents, depending upon factors such as geographical
location, level of wealth, type of economy,and density of population.
Environmental problems come in all shapes, sizes, and time-scales, from the
immediate and the local (a water source poisoned with toxic metals, for example)
to the global and the long-term (global warming, for example). The wealthier,
'developed' countries of the world are disproportionately responsible for the
environmental degradation that has occurred to date, although the balance of
responsibility may in the future change with economic development and population
growth.
Q2.77
Can we learn how to 'manage' the Earth? Probably not. Our
world evolved over billions of years, and the processes that shaped this
evolution are not fully understood. The functioning of any ecosystem is
extremely complex; even on a small scale, a vast number of interactions take
place that we do not understand. We cannot manage the global ecosystem as if it
were a giant machine.
Q2.78
Can we learn to manage our relationship with the Earth? Yes.
Managing our own activities is both possible and necessary. We will prosper
without degrading our environment to the extent that we learn how to manage our
relationship with the ecosystems of which we are part.
Population
Population is one of the most important factors that affects the relationship of a species to its environment. In the case of the human species, it is also one of the most controversial. This section explains some of the basic facts and concepts relating to growth in human populations, and describes the relationship between population growth and the biosphere.
Q2.79
Has human population grown over time? Yes. The number of
people on the planet has increased throughout human history. Over thousands of
years human population grew very slowly, reaching 1 billion in 1800. By 1930 it
had doubled; by 1975 it had doubled again. In mid-1990, world population was
estimated to be 5.3 billion; it is expected that another billion will be added
by the year 2000, and that by 2025 world population will reach 8.6 billion.
Q2.80
Why has world population grown so rapidly over the last 200
years? Population has grown because mortality declined faster than fertility.
Improved sanitation, health care, medicines, shelter, and nutrition have led to
dramatic increases in life expectancy. Fertility, on the other hand, began to
decline more recently than mortality, and it declined more slowly. The result
has been population growth.
focus
In everyday speech we use the word `fertile ' to refer to
people who are capable of reproducing. Demographers, however, call this
`fecundity' the physiological capacity of couples to reproduce. They reserve the
word `fertility' to refer to the reproductive performance of whole populations
the number of live births in a population.
Q2.81
How do we measure fertility and mortality? These variables
can be measured in a number of different ways. The simplest are the 'crude'
birth and death rates, which measure the average number of live births and the
average number of deaths for every 1000 people in a single year. In 1990, for
example, there was an average of 26 live births and 9 deaths for every 1000
people on the planet.
Q2.82
Has population growth occurred evenly throughout the world?
No. After growing rapidly in the nineteenth and early twentieth centuries, the
population of the industrialized countries of the world has stabilized. In the
less developed regions of the world rapid population growth began later but has
not yet ceased. As a result, the developing countries are home to an increasing
percentage of the world's population.
In 1950, North America, Europe and the USSR contained almost 30% of the world's people. By 2025, they will contain only 14%. India, in contrast, will be the home of 17% of the world's population in 2025. The vast majority of population growth today is occurring in the poorer, less developed regions of the world.
Q2.83
Why is fertility higher in countries considered 'less
developed'? One of the factors that determines the fertility of a society is the
rate at which women of childbearing years are having children or, to put it
another way, the average number of children a woman will have in her lifetime.
This is referred to as the 'total fertility rate'. In less developed countries
there are a number of socio-economic realities that lead women to have more
children:
Q2.84
Is population growth really an environmental issue? The size
of the human population is one of the factors that determines what kind of an
impact we have on our environment. But it is not the only one. The impact of
people on their environment depends not only on their numbers but also on their
location in the biosphere, their levels of consumption of energy and materials,
and their technology.
One way of describing the relationship is with the following equation: I=PAT. 'I' stands for Impact. 'P', 'A' and 'T' all stand for factors that determine what kind of an impact we have: 'P' represents Population size, 'A' represents Affluence (levels of per capita consumption and related waste), and 'T' represents Technology's polluting effects. Although it involves great simplification, this model conveys the idea that environmental impact results from a combination of factors, each of which magnifies the others' effects.
Q2.85
Are there other factors that determine environmental impact?
Yes. Although affluence and polluting technologies are the causes of
environmental degradation with which we are most familiar in Canada, there are
others. Our natural environment can be negatively affected by poverty,
international debt, warfare, international trade policy, and many other factors.
Q2.86
Was population growth the primary cause of the environmental
degradation that has occurred over the last 40 years? No. The scale and rate of
environmental transformation have grown dramatically during this period. World
population has also grown dramatically, leading some people to see population
growth as the key environmental issue. Yet population growth was not the major
cause of this increase in environmental impact. Population grew rapidly in the
developing countries, not in the developed ones. It is the developed countries,
however, that are disproportionately responsible for the environmental
degradation of the last 40 years. In 1985, for example, the developed countries
of the world generated more than three quarters of the world's waste, even
though they contained less than one quarter of the world's population. At
present these countries also consume 75% of all energy used, 79% of all
commercial fuels, 85% of all wood products, and 72% of all steel products. As a
planet, most of our current environmental problems are the result of
rich-country behaviour where rapid population growth is not a problem.
Q2.87
Does this mean that population growth is not an environmental
issue? No. For the next 40 years at least, the world's population will grow
rapidly, and most of this growth will take place in developing countries. The
result will be an increase in the developing world's share in global
environmental degradation. Especially troubling for developing countries are the
likely consequences of population growth on soil, urban areas, and water
quality.
Q2.88
Is population growth the ultimate cause of urbanization,
water shortages, and land degradation? No. Even if populations were not growing
in developing countries these problems would still exist. Poverty, unequal
patterns of land distribution, bad government policies, warfare, etc., would all
still be present and all still be damaging the environment. But even if
population growth is not the root cause, it does make the situation worse.
Stopping population growth will not do away with environmental degradation, but
not stopping population growth will make the situation very much worse. In some
of the poorest countries of the world, population will double in a mere 25 to 30
years. This is the case in much of sub-Saharan Africa, for example, where
population has already more than doubled in the past three decades. In these
countries, economic growth has stalled, per capita food production has declined,
and international debt has grown. Population is expected to go from 500 million
today to over 1 billion in 2010 and to 1.6 billion in 2020. In situations like
this, limiting population growth will at the very least buy time.
Q2.89
What can be done to slow population growth? In order for
fertility rates to decline rapidly, progress must be made on four fronts.
Incomes of poor households must rise, child mortality must decline, educational
and employment opportunities for women must increase, and access to family
planning services must expand.
Of these, investments in female education have proven to be the most effective in reducing population growth and promoting development. Better educated women have fewer, healthier, and better educated children, and are more productive at home and at work.
Technology
In the industrialized countries of the late twentieth century technology is everywhere and technological change is extremely rapid, raising both hopes and fears for our environment. This section outlines the nature and history of technology, and looks at some of its implications for the environment.
Q2.90
What is technology? The term 'technology' as it is used today
refers to all of the various tools we use in order to modify our environment and
ourselves. 'Tools' should be understood in the broadest sense to include not
only physical objects but techniques ways of doing things, such as ways of
organizing a factory or ploughing a field. It has been suggested that tool-use,
along with language and politics, is one of the defining characteristics of the
human species.
Q2.91
What is the relationship between science and technology? The
relationship between science and technology has changed greatly over time.
Originally science the pursuit of knowledge was the domain of aristocrats, while
tool making was the job of craftsmen. Technology grew out of people's personal
experiences with the way things behaved, and out of know-how handed down over
the generations. It was not until the Middle Ages that science and technology
began to draw closer together. Following the scientific revolution that began in
the sixteenth century, science increasingly relied on tools such as the
telescope and the microscope; the work of scientists came to depend more and
more upon the work of craftspeople. By the nineteenth century, tool making in
turn began to be influenced by scientific principles and theories. Today,
science and technology are intertwined to the point that it is difficult to
separate the two.
Q2.92
How has technology changed over time? The record of human
existence on Earth both archaeological and historical shows continued
technological improvement. For better or worse, the undeniable trend of human
history has been toward greater and greater extension and refinement of our
ability to manipulate our environment with the aid of technology. The pace of
technological change today is very rapid in comparison with previous epochs;
this is frequently taken to be a defining characteristic of our age.
Q2.93
Does technological change pose a threat to human society and
the environment? Over the long term, technological change has led to
incalculable benefits for humans. On average, we live longer and healthier lives
today than did our prehistoric or medieval ancestors. At the same time,
technological improvements have allowed us to kill ourselves in unprecedented
numbers in this century through war and other forms of political violence. The
central dilemma of the technical progress of the past 250 years is that it has
outstripped moral and political progress progress in deciding how technology
will be used.
Q2.94
What technological changes have had the greatest impact on
modern society and its natural environment? The technological changes that have
had the most effect on modern society and its environment are, arguable, those
associated with the harnessing of energy. This would include the invention of
the steam engine, the electro-magnetic generator, and the internal combustion
engine. These and other inventions made possible the industrialization and
urbanization of England and later Europe and North America and Australia. They
also made possible rapid transportation of people and materials over long
distances, allowing the development of a global economy and of modern warfare.
The environmental consequences have included increased waste, the release of
polluting materials into the biosphere, and the depletion of renewable resources
such as fish, forests, and soil.
Q2.95
Are the environmental consequences of technological change
always purely negative? No. Technological changes can, in fact, lead to
improvement in the quality of our environment. For example, when the car
replaced the horse it rid the city of heaps of dung, and was hailed as a major
contribution to the improvement of public health and sanitation. In time, of
course, automobile transportation led to new types of environmental problems:
smog, acid rain, global warming. Yet, in recent years, technical changes have
allowed us to switch from leaded to lead-free gasoline, and to build smaller,
more efficient cars. Air quality in most of the industrialized world is now, in
fact, better than in the recent past. The effect of technology on the
environment is thus far from being purely negative.
Q2.96
Can technology solve all of our environmental problems? There
is, at present, much debate on the question of the extent to which technical
fixes will be able to solve environmental problems. The major limit to the power
of technology is that many problems are not primarily the result of technical
inadequacy. We have the knowledge and technical ability, for example, to cure
many of the most deadly communicable diseases; all that must be done is to
ensure clean drinking water and adequate sanitation for all of the world's
population. The barriers to accomplishing this are political, social, and
economic, not technical.
Economy
The economic activities of the human species have a great effect on the environment, while being at the same time dependent upon it. This section looks at some of the key issues relating to the interaction of economics and ecology.
Q2.97
What do we mean by the 'economy'? The term 'economy' is
derived from the ancient Greek words 'oikos', meaning 'home', and 'nomos',
meaning 'law'. In its original sense, it meant something like 'household
management'. The modern sense of the term is quite different. A modern economy
consists of a system by which goods are produced, distributed, and consumed. It
includes, for instance, the extraction of resources, the production of energy,
and the manufacturing, transportation, and selling of goods. Economics is one of
the things that relates people to each other in a society, along with politics,
culture, and religion.
Q2.98
How does the modern economy fit into the biosphere? In purely
economic terms, the biosphere is considered to be a source of resources and a
'sink' for wastes. The production, consumption, and distribution of goods is
dependent upon the biosphere for materials (such as timber, minerals, and soil),
energy (such as firewood and fossil fuels), and for the disposal of waste (such
as effluent, emissions, and landfill). From an ecological perspective, the human
economy is a set of flows of energy and materials that exists alongside natural
biospheric processes. The economy is dependent upon these processes, but also
has a significant and often negative effect upon them.
Q2.99
Is this interdependence recognized by economic thought? In
the past, the interdependence of economic and ecological processes was too often
overlooked in our economic thinking. The biosphere tended to be conceived of as
a limitless source of 'sources' and 'sinks', if it was considered at all. In
previous centuries, when the scale of human activities was small compared with
the processes of nature, this was of less consequence. Today, the
interdependence of the environment and the economy cannot be ignored. In the
past 200 years, human production and consumption have grown dramatically.
Today's modern, industrial economies have a great impact upon the natural world,
and yet they remain crucially dependent upon it.
Q2.100
Is the 'free market' to blame for environmental degradation?
It has been argued that our competitive market economy, with its emphasis upon
ever-greater levels of consumption and production, is responsible for the
environmental degradation that we have witnessed over the past decades.
Capitalism, it is argued, is to blame for the sorry state of the biosphere.
There is no disputing the fact that high levels of consumption and production have had and continue to have serious environmental impact. Yet in Eastern Europe and the former Soviet Union, where markets were severely restricted up until recently, environmental degradation is extreme. It seems that capitalism and socialism have both been environmentally destructive. In fact, there is evidence that the market system has done better. Not only are countries in Eastern Europe today among the most polluted in the world, they are experiencing severe economic difficulties, and so lack the funds necessary to clean up the environment and to convert to more environmentally friendly means of production.
Q2.101
Is economic wealth the cause of environmental degradation?
It is true that most global environmental degradation has been caused by the
wealthy, industrialized societies of the world. Modern industrial economies
mobilize great quantities of energy and materials, and over the last 40 years
this has had a dramatic effect on the environment. In addition, high levels of
wealth can lead to waste, as the efficient use of resources may no longer be
seen as a necessity.
Yet, poverty too has negative environmental consequences. The very poor, near the edge of subsistence, are pre-occupied with the task of immediate survival. Given the precariousness of their existence, they do not have the luxury of using the natural resources to which they have access in a sustainable way. Deforestation, soil erosion, and desertification are environmental problems that are often associated not with great wealth but with poverty. Wealth and poverty each have their own environmental consequences.
Q2.102
What are the economic reasons for environmental degradation?
From an economic point of view, environmental damage occurs as a result of
environmental resources being undervalued. We do, of course, value things such
as wilderness, clean air, and wildlife highly; we do so for aesthetic and
spiritual reasons. Yet the prices our markets allocate to these resources do not
always reflect this value.
Q2.103
Why are environmental resources sometimes undervalued? The
prices we pay for the things we buy reflect many costs: raw material extraction,
production, advertising, and distribution. But there may also be environmental
costs associated with the production of goods. Often these environmental costs
are not borne (or at least not primarily borne) by the persons producing the
goods in question. They are for this reason labelled 'external costs'. When
producers don't bear these costs, they are not reflected in the prices they
charge.
Let us say, for example, that a chemical factory located on a river discharges toxic waste into the water. The environmental consequences of this activity are not borne by the company producing the chemicals, but by those who live downstream. As a result, the prices of the chemicals produced by this company will not reflect the environmental costs associated with their production. If the company was forced to pay these costs, prices would increase, encouraging consumers to use other chemicals, and encouraging the company to find ways of reducing the amount of toxic waste it discharges.
focus
An external cost exists when the economic activity of one
person or company causes an uncompensated loss in welfare on the part of
another. The costs of pollution, for example, are often not borne by the
polluter but by the victims of the pollution. From the point of view of the
polluter, the cost is said to be external. Since these costs are not borne by
the polluting producer, they are not reflected in the prices the producer
charges, and the producer has no economic incentive not to pollute.
Q2.104
What are 'scarce' and 'free' goods? Economists label as
'scarce' those goods that are not immediately available to all. This means that
even goods we normally think of as abundant (such as paper clips or coat
hangers) are, in economic terms, scarce. In a market economy, markets exist for
all scarce goods. Markets do not exist for non-scarce goods, since these goods
are unlimited in supply and readily available to all they are 'free goods'.
Air, for example, has traditionally been thought of as a non-scarce good. We do not buy and sell air, we simply breathe it. Yet the capacity of the atmosphere to replenish its stocks of clean air is not in fact unlimited. Increasingly we are coming to realize that many of the goods we have placed in the 'free good' category are not in infinite supply, and that in order to avoid their further depletion, we must start treating them as scarce.
Q2.105
Can consumption have external environmental costs too? Yes.
Driving cars, for example, contributes to smog, acid rain, and global warming.
The costs associated with these environmental problems are external from the
point of view of the car driver since they are long-term costs borne by the
population in general, not just those who drive cars today. Because car drivers
per se don't pay, no individual car driver has an incentive to reduce the amount
he or she drives. Taxpayers may end up paying for environmental clean-up, but
car drivers as such will not, because the effects and costs of automotive
transport are spread out over the entire society (or even the whole planet). If
the impact of environmental degradation always fell only on those responsible
for it, there would be no problem. As this is not the case, efforts are required
to tie environmental costs more closely to environmentally irresponsible action.
Q2.106
What is the 'polluter pays' principle? The polluter pays
principle is the belief that whoever causes environmental degradation should
bear the costs associated with it. Although straightforward in theory, it is
often difficult to apply in practice, since it is not always clear who the
polluter is. Where pollution results from the production of a good, for example,
it would seem that the producer is the polluter. Yet in any market transaction
there is always a buyer and a seller. Both the consumer who buys the good and
the producer who sells it benefit from the transaction. They both 'caused' the
pollution it would not have occurred had either of them refused their part in
the bargain. Presumably then, they both should pay (although perhaps not in the
same proportion). And there are often third parties who benefit from such
transactions; polluting primary industries often support local service
industries, for example. These third parties also benefit from the polluting
activity, and so it might be expected that they should contribute to pollution
clean-up as well.
Q2.107
Does this complexity mean that the 'polluter pays' principle
is invalid? No. It remains reasonable to demand that environmental degradation
be paid for in proportion to the amount of benefit drawn from the activity that
caused the degradation. We must, however, exercise caution in applying this
principle. The economic system which joins us together is complex; very few of
us are innocent of causing pollution in one way or another.
Q2.108
Is there a way to make people who damage the environment pay
the costs? Yes. People can be made to pay for environmental damage by including
the costs of environmental degradation in market prices through realistic
resource pricing and the use of economic instruments such as taxes and permits.
These measures 'internalise' the external environmental costs; that is to say,
they distribute the costs of environmentally damaging production and consumption
to those engaged in it. Many governments are at present studying or implementing
such 'economic instruments'.
Q2.109
What are some examples of such 'economic instruments'? A
familiar example of an economic instrument is the deposit-refund schemes that
are used for reusable or recyclable products such as bottles. A charge is
imposed on the product at the point of sale, but refunded if the product is
returned to a collection agency. 'Tradeable permits' are another example.
Sources of air pollution, for example, can be issued permits to emit a certain
amount of a polluting substance. Permits are then bought and sold between
sources, enabling pollution reduction to occur in an economically efficient way.
Resource Use
This section describes the different types of natural resources human societies depend upon and some of the economic and environmental concerns associated with their use.
Q2.110
What are the different types of resources our economy uses?
Natural resources are derived either from the air, soil, water, and organisms of
the biosphere, or from the subterranean areas of the earth. Resources of the
first type are normal parts of ecosystems, and are labelled either 'renewable'
or 'replenishable'. Resources of the second type are labelled 'non-renewable'
and 'non-replenishable'. Since resources of the second type are derived from
beneath the Earth's crust, the Earth's ecosystems have mostly evolved with only
episodic or weak exposure to them. In this sense, many non-renewable and
non-replenishable resources are 'foreign' to the biosphere; they can hence be
harmful to organisms and disrupt ecosystems. Levels of these materials in the
biosphere have increased over the past 200 years as a result of human
activities.
Q2.111
What are some of the environmental concerns associated with
the harvesting of renewable resources? There are many different environmental
issues that are raised by the use of renewable resources. In the case of
forestry, for example, habitat loss is a key issue; there is concern that
logging threatens some species with extinction. In the case of agriculture, some
of the major issues relate to land use and water pollution. The main issues
posed by the processing of wood products concern air and water pollution.
Generally speaking, it is not an exaggeration to say that renewable resource
production has implications for all facets of the environment.
focus
Renewable resources, strictly speaking, are organisms and
their products. Plants, animals, and micro-
organisms are the only
resources which can, by reproduction and growth, actually increase in quantity.
Sometimes the term `renewable' is used to refer to both renewable and
replenishable resources.
Replenishable resources are the non-organic resources such as air, water,
soil, and climate that
form the matrix of ecosystems and support life.
They are replenished and maintained by natural cycles of varying (but relatively
rapid) speeds.
Q2.112
What is the key economic concern associated with the
harvesting of renewable resources? Fisheries, forestry, agriculture, and other
economic activities dependent upon renewable resources form an essential part of
the economies of most countries in the world. The key economic concern
associated with these resources is that we may be using them more quickly then
they can regenerate themselves, threatening to leave reduced stocks for future
generations. The commonly used analogy is that we must live off the 'interest'
supplied by our natural 'capital', but not dig into the capital itself; to do so
would yield short-term benefits, but endanger future prosperity. For example, if
forests are cut improperly, their ability to grow back may be impaired, leaving
future generations with a depleted resource base. Although simple to explain in
theory, it is often very hard to determine in practice what is a sustainable
rate of resource use.
Q2.113
What are the environmental concerns associated with the use
of replenishable resources? The environmental issues surrounding the use of
replenishable resources all have to do with the effects of waste flows to the
environment. Whether as effluent to water, emissions to the atmosphere, or solid
garbage to landfills, the by-products of our production and consumption can
damage ecosystems and poison our environment. A key issue is how to keep waste
flows to the environment at or below its 'assimilative capacity' the maximum
amount of waste it can absorb over a certain period of time without degradation.
The problem is that it is often difficult to determine beforehand what this
point is.
Q2.114
What are the economic concerns associated with the use of
replenishable resources? The economic concerns over the use of replenishable
resources focus upon the consequences of air and water pollution for human
health, agricultural productivity, and the health of economically valuable
wildlife. Toxic effluent, acid rain, global warming, ozone depletion, and
environmental issues related to the use of our environment as a 'sink' for
wastes can all pose economically significant threats to human and non-human
welfare.
Q2.115
What are the environmental concerns associated with the use
of non-renewable and non-replenishable resources? Various environmental issues
are raised by the retrieval, processing, transport, use and disposal of these
resources. For example, land use associated with coal and mineral mining may
disturb or displace habitat. Smelting of metals and refining of fuels can
release pollutants into surrounding air, soil, and water, degrading habitat and
posing health risks for both humans and wildlife. Similar impacts occur due to
fuel leaks and spills. The burning of fossil fuels contributes to global
warming, smog, and acid rain. Those products made from non-replenishable
resources, if not re-used or recycled, end up in landfills, adding to the
problem of accumulating solid waste.
Q2.116
What are the economic concerns associated with the use of
non-renewable and non-replenishable resources? The environmental impacts
addressed above degraded air, land, and water, and health problems in human and
wildlife all translate into costs. For example, these costs are realized in
lower harvest sizes of timber and fish, high health care costs for treating
respiratory ailments, and the cost of rehabilitating degraded areas, such as
cleaning up oil spills.
focus
Non-renewable and non-replenishable resources are
materials from the Earth's crust such as ores,
minerals, and fossil
fuels. Nature does not replace these resources within time frames relevant to
human society. Non-renewable resources (oil and natural gas, for example) are
used as energy sources; once consumed they are gone, leaving only waste heat and
other by-products. Non-replenishable resources (iron and tin, for example) are
not consumed, but rather converted into products for sale; once dispersed via
the market, these materials are unavailable for further use unless gathered and
recycled. The term `non-renewable' is sometimes used to refer to both
non-renewable and non-replenishable resources.
Q2.117
What does 'sustainability' mean in the case of non-renewable
and non-replenishable resources? Unlike renewable and replenishable resources,
the resources from the Earth's crust cannot, even in principle, be used
'sustainably'. They do not replace themselves once used (at least not within
time frames relevant to human society). This means that there is no level at
which our use of them could continue forever; at any fixed rate of consumption
such resources will eventually be entirely depleted (although this might take a
very long time).
Q2.118
Will we run out of non-renewable and non-replenishable
resources? It was once felt that the finite amount of non-renewable resources
that are available in the biosphere placed a limit upon economic growth that
would be reached in the near future; as stocks of resources were depleted,
economic growth would come to a halt. Recently, however, estimates of the
quantity of non- renewable resources have been revised upward. More importantly,
it is increasingly well understood that the market system does much to ensure
that there will be sufficient supplies of natural resources, at least for the
foreseeable future.
Q2.119
How does the market system ensure that we will not 'run out'
of natural resources? As resources become more scarce they become more costly to
exploit, and more expensive to consume. This leads consumers to use these
resources more efficiently, and to switch to other, cheaper alternatives. Price
increases also encourage the development of alternative processes of production
and alternative sources of energy. For these reasons, it seems unlikely that our
economy will suffer a deficiency of non- renewable resources in the foreseeable
future.
3. The Biosphere - Issues
