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Impact of Technology on Environment


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Please visit homepage------------- The Sixth Assessment Report (AR6) by the Intergovernmental Panel on Climate Change reveals that the impacts of climate change are escalating at a faster pace that the ability of both nature and humanity to adapt. The perils are visible and widespread, and report shows that countries are not prepared enough against the disasters to come. Halit Eren, in his latest publication titled “Impact of Technology on Environment: Climate Change and Instrumentation” (published by Xlibris AU), puts a spotlight on one of the crucial areas that directly and indirectly affect the environment: technology. This book contains concise but comprehensive information on the environmental effects of technology throughout the history. It starts with the position of the Earth in the universe and human history 70,000 years ago — explaining the fundamentals of technologies from early stone ages to the current space age. By developing and using technologies, humans have been causing significant changes on the environment. The author expresses, explains and raises concerns on these changes that the environment seems to be helpless in the way that humans currently use it. “Human interaction with the environment appears to be opportunistic always in favor of human,” Eren states. “Humanity is causing climate change, ozone depletion, diminishing biodiversity, hazardous and nuclear substances and wastes damping, desertification, land degradation, air pollution, and soil pollution. The offerings and the spoils of the nature were fully exploited without any questions asked on the changes inflicted on the environments and without considering any consequences.” “Impact of Technology on Environment: Climate Change and Instrumentation” highlights where the problems are coming from and, more importantly, how humankind can organize to solve the problems. Instrumentation, measurement, and information sciences allow people to identify and understand environmental changes with a high degree of precision. The book offers remedies to mitigate environmental problems by new technological developments. It also guides readers on environmental protection organizations and groups
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At the beginning of the third millennium, many global environmental problems, such as diminishing biodiver-
sity, climate change, ozone depletion, overpopulation, and hazardous wastes, are causing significant concerns.
Problems of air and water pollution and toxic waste disposal are common in all industrialized countries. In
developing nations, millions lack access to sanitation services and safe drinking water, while dust and soot
in air are said to contribute to hundreds of thousands of deaths each year. Moreover, serious damage from
pollution and overuse of renewable sources challenges world fisheries, agriculture, and forests, with significant
present and possible adverse effects on the physical environment (1).
It is undoubtedly true that twenty-first-century people are causing significant environmental changes,
notably in the biosphere, hydrosphere, and atmosphere. These changes are the results of local actions of many
individuals accumulated in time and space, leading to global environmental problems (2). For example, in the
United States, emissions of primary pollutants into the atmosphere are due to transportation (46%), fuel con-
sumption in stationary sources (29%), industrial processes (16%), solid waste disposal (2%), and miscellaneous
(7%). The breakdown of pollutants by weight is 48% carbon monoxide, 16% nitrogen oxides, 16% sulfur oxides,
15% volatile organic compounds, and 5% particulate matter. Other developed countries exhibit similar statis-
tics, but for developing countries these percentages vary considerably since their activities are quite different
Discussions of the environmental impact of technology can be approached in many interdisciplinary ways.
The natural sciences are concerned with anthropogenic planetary processes and transformations—those in-
duced by human activities. In this respect, the analysis and discussions are concentrated on physical, chemical,
and biological systems through diverse disciplines such as geology, atmospheric chemistry, hydrology, soil sci-
ence, and plant biology (4). However, many social science professionals are also involved in these discussions,
since analysis of environmental changes also involves social causes. The scope of human intervention in the
environment and how it is managed bear particular importance in that humans are now the main causes of
environmental changes (5).
People affect the biophysical system by diverting resources (e.g., energy and matter) to human uses, and by
introducing waste into the environment, thus causing environmental problems. Some environmental problems
occur locally on micro levels (water quality and quantity, noise, local air pollution, hazardous materials, traffic,
overcrowding, etc.) and can be solved by local decision makers, while others take place globally on the macro
level (acid rain, desertification, natural-resource depletion, climate change, depletion of biodiversity, hazardous
materials, toxic and nuclear wastes) and necessitate international cooperation. However, there are crucial
manifestations of global environmental problems as local problems accumulate to become global crises (5). In
this article both micro-level and macro-level environmental problems will be discussed, and references to the
sources of information will be made when necessary.
One of the major causes of environmental problems is technology and how humans use it. Technology
can be both source and remedy of environmental problems. It also plays a critical role as an instrument for
observing and monitoring the environment on global and local scales (4). Although technology has a crucial role
in finding solutions to environmental problems, by itself it cannot fix anything. Technology is a social construct
Fig. 1. Representation of global environmental system in the form of biophysical earth system and human earth system.
Humans continuously interact with the biophysical earth system, and for the first time in history they are not dominated by
the environment. Humans have the technology and ability to influence and upset the interaction between the components
of the biophysical earth system.
responding to social, cultural, political, and economic demands and priorities. These factors determine not only
whether technology is used positively or negatively, but which forms of technology are developed, accepted, and
used in the first place.
Environmental impacts of technology depend on what technologies are used and how they are used.
Technology is an intermediary agent of global change rather than the prime cause of it; that is, the design,
selection, and application of technology are a matter of social choice. Therefore, in a balanced article such as
this one, it is important to maintain a continuous link between technology and human behavior (economics,
culture, demography, etc.).
This article considers natural science and social science in an interactive manner for the study of what can
broadly be termed biophysical earth systems and human earth systems. The biophysical earth system can be
viewed as having five major components: the atmosphere, hydrosphere, cryosphere (frozen water), lithosphere
(rock and soil), and biosphere (living things). The human earth system can be analyzed into population,
economic, political, and technological spheres, all interacting with each other as illustrated in Fig. 1. The
human system interacts strongly with the biophysical system.
This article is divided into two major sections.
In the first section, environment and technology are defined and discussed separately. In the first half
of that section, the environment is viewed as the biophysical Earth system having as major components the
lithosphere, atmosphere, hydrosphere, cryosphere, and biosphere. In the second half, technology is grouped into
three main components: agriculture, industry, and services. A brief historical information is provided for each
of these components in order to provide a strong background for understanding how and why that particular
technology exists in its current form.
Undoubtedly the growth and location of the world’s population are the key determinants of global environ-
mental change. Therefore the relationship between population and environment and between technology and
economics will be highlighted. The scientific methods for assessing and controlling the effect of technology on
the environment will be discussed, and issues surrounding international cooperation will be briefly explained.
The understanding of this first section is important in that the development and environmental effects of
technology are dependent on human behavior, and on the social and economic forces in place.
The second section comprises the bulk of the article. The impact of technology in specific areas, such as
land use, soil contamination, toxic waste, water pollution, resource depletion, air pollution, greenhouse effect,
noise and electromagnetic pollution, climate changes, and ozone depletion, will be discussed in detail, and
conclusions will be given.
Environment and Technology
Environment. Environment concerns all individuals and living things, since it is a common, a com-
modity possessed by all. As this article deals on the effect of technology on the environment, it is important to
understand its meaning fully. Among many other definitions, here, the environment is defined as the conditions
under which an individual or thing exists, lives, or develops. In the case of humans, environment embraces the
whole physical world, and as well as social and cultural conditions. The environment for humanity includes
factors such as land, atmosphere, climate, sounds, other human beings and social factors, fauna, flora, ecology,
bacteria, and so on.
Humans are land-bound; therefore the lithosphere, which consists of land (rocks and soil),
has special importance in the formation of civilizations.
The earth may be viewed as made up of three layers: the core, the mantle, and the crust (6). The core and
mantle together account for well over 99% of Earth’s mass and volume. In the composition of the earth as a
whole the crust has little importance, but it bears special significance for humans and other living things. The
crust can be divided into two parts: the upper crust and the lower crust. The upper crust itself has two parts.
The top few kilometers are variable and are largely formed by sedimentary, igneous, and metamorphic rocks
and soil. The sedimentary rocks are those that have been built up from layers of material deposited by water
and wind. The rest of the upper crust consists largely of igneous rocks and metamorphic rocks. These two types
account for at least 85% of the mass and volume of the upper 20 km of the crust.
Soils form on land surfaces where the hard rocks or soft loose sediments are modified by many physical,
chemical, and biological processes. Soil is basis of agriculture and thus of civilization. Soil becomes suitable for
agriculture when it becomes a mixture of rock and fresh or decayed organic matter.
The lower crust is believed to contain largely coarse-grained igneous rocks.
The atmosphere is a mixture of gases; it contains 75% nitrogen, 23% oxygen, 0.05% carbon
dioxide, and 1.28% argon. There are other inert gases such as helium and neon in minute amounts. It also
contains water vapor in variable quantities from 0.01% to 3%. Another variable component is sulfur dioxide,
estimated to be present in a mass of about 10 million tons in the atmosphere at any time. At heights of 15 km
to 50 km above the earth’s surface there is a layer of ozone; the estimated amount of ozone is about 4 billion
tons (3).
The atmosphere is divided into various layers. The first 11 km is known as the troposphere; it occupies
about 1.5% of the total volume but contains about 80% of the mass. Near the ground level visible and infrared
radiation is absorbed and the temperature is high. The second layer (up to 50 km) is called the stratosphere.
This is the region of the ozone layer in which the sun’s harmful ultraviolet rays are absorbed. The next layer,
the mesosphere, extends from the stratosphere a further 80 km. Above the mesosphere lies the thermosphere.
This layer absorbs ultraviolet rays and is the source of the ionosphere.
Since the formation of atmosphere, there has been close interaction between the biosphere and atmo-
sphere, one influencing the other. This continues today as society affects the chemical composition of atmo-
sphere through pollution and deforestation.
The earth is a watery planet. Land today occupies one-third of Earth’s surface covering
about 36% (29% exposed and 7% under water). The remaining 64% (362 million km2) of Earth’s surface is
covered by oceans with a mean depth of 3.8 km. The ocean contains 1350 million km3of water. Ocean water
is not pure; it contains virtually all elements, though most occur in minute amounts. Prominent solutes are
various salts, collectively called salinity. Approximately 97% of the water on the earth is in the oceans. Fresh
water makes up only about 85 million km3. Of this, approximately 60 million km3is groundwater, 24 million
km3is in ice sheets, 300,000 km3is in lakes, reservoirs, and rivers, less than 100,000 km3is in soil moisture,
and 14,000 km3is in the atmosphere.
Water is naturally cycled between land, sea, and atmosphere, as shown in Fig. 2. The global hydrological
cycle is important for all living things. Water evaporates from the oceans, seas, and land and redistributes
around the globe. Although more than 90% of water precipitation returns directly to the oceans and seas, a
significant portion is carried by winds over the continents, where it falls as rain and snow. Upon reaching
the ground, a portion of the water is absorbed by the soil, and the remaining water evaporates back into the
atmosphere or forms rivers, streams, lakes, and swamps as groundwater. However, factors such as climate as
well as human activities can affect the balance of the hydrological cycle (6).
The annual transport of water is estimated to be about 600,000 km3/yr. Precipitation over land is about
120,000 km3/yr, of which 70,000 km3/yr is evaporated. Currently, humans use about 3000 km3/yr of water,
which shows that there is no immediate scarcity. Nevertheless, both quantitative and qualitative trends in
water demand caution.
“Cryo” means cold or freezing. The part of the earth’s surface, such as glaciers, sea ice, and
areas of frozen ground, that remains perennially frozen covers 15 million km2(about one-tenth of the land
surface). It is estimated that 24 million km3(about 2%) of the water exists in the cryosphere (6). The cryosphere
directly influences climate through enhancing the equator-to-pole thermal gradient. It also plays an important
role in the global energy balance and water mass balance. It is estimated that the melting of ice in Antarctic
alone could result a rise in the sea level by 18 m (3).
Studies in the cryosphere yield accurate observations on climate patterns on long time scales. Modern
scientific methods allow the unveiling of historical information on the earth’s climate changes through the
study of ice sheets in Greenland and at the North and South Poles. Global changes in CO2,CH
4, volcanic
activities, biogenic sources, dust, radioactivity, and so on can also be studied (3).
The biosphere contains the ecosystem and biological diversity (biodiversity) of the world.
Biodiversity encompasses the number and variability of all living organisms, both within a species and between
species. Estimates for the number of species in the world range from 5 to over 50 million, of which only about
1.7 million have been described to date (7). Estimates for the loss of species within the next 50 years are 5% to
50%. Anthropogenic factors responsible for loss of biological diversity may be listed as:
(1) Destruction, alteration, or fragmentation of habitats
(2) Pollution and excessive application of agrochemicals
(3) Greenhouse effects and depletion of ozone layer
Fig. 2. Water is involved in the natural hydrological cycle between land, sea, and atmosphere. Human activities interferes
with this cycle and add additional components such as exposure of fossil fresh underground water that has been in the
ground for millions of years and not very likely to enter the natural cycle.
(4) Overexploitation of flora, fauna, and marine life
(5) Deliberate annihilation of pests or introduction of pests
(6) Deliberate importation of exotic species
(7) Reduction of genetic diversity
Technology. Technology is manmade hardware and knowledge used to produce objects to enhance
human capabilities for performing tasks they could not otherwise perform. The objects are invented, designed,
manufactured, and consumed. This requires a large system with inputs such as labor, energy, raw materials,
and skills. Throughout history, humans have acquired powerful capabilities by developing and using technology
to transform the way that they lived; formed societies; and affected the natural environment on local, regional,
and global levels (4).
It is important to understand that the development and acceptance of technology is dynamic, systematic,
and cumulative. New technologies evolve from uncertain embryonic stages with frequent rejection of proposed
solutions. If they are accepted, diffusion follows, and the technologies continue to grow and improve with
widened possible applications to be integrated with the existing technologies and infrastructures. Demand
growth is the result of complex interacting demographic, economic, and lifestyle forces. Ultimately, the im-
provement potential of the existing technology becomes exhausted and the diffusion saturates, paving ways
for the introduction of alternative solutions (5). At any time, three different kinds of technology can exist: (1)
mature technology for which no further improvements are possible, (2) incremental technology that can be
improved by learning and R&D, and (3) revolutionary technology.
Technology’s impacts on the environment have been both direct and indirect.
Direct impacts are mostly made by new technologies by the creation of entirely new substances [(e.g.,
DDT and chlorofluorocarbons (CFCs)] possible. Many of these new substances lead to novel and direct
environmental impacts.
Indirect impacts arise from the human ability to mobilize vast resources and greatly expand economic
output by means of productivity and efficiency gains from continuous technological change. For example, the
disappearance of infectious diseases like typhoid and cholera has increased the life span, and that, together
with shorter working hours and rising incomes, has changed time budgets and expenditure patterns,
allowing the manipulation of human behavior to cause significant environmental changes.
The impact of technology on environment is not uniform throughout the world, since the development and
use of technology is not uniformly distributed. That is because development, acceptance and use of technology
by humans is uneven and varies vastly from region to region and nation to nation, depending on their economic
and social conditions (5). Today, still, there are billions of people who have been excluded from current technology
or have a very small share of it.
The effects of technology can be divided into three main areas: agriculture, industry, and services.
Next to fire, agriculture is the oldest human technology and has affected the natural envi-
ronment for millennia. Agriculture is the largest user of land and water resources. Intensive soil cultivation,
reservoirs, and irrigation have been part of many civilizations since antiquity. Since the 1700s the world popu-
lation has risen considerably. To be able to supply food for the rising population, an estimated 12 million km2
of land has been converted from forests and wetlands to croplands.
One of the major impacts of technology is through vastly improved agricultural practices in the last
few centuries. This improvement has permitted an increasing share of the growing population to move to
cities. In most industrialized countries today, less than 3% of the work force works on farms. Prior to the
industrial revolution, and still in many countries, that figure was about 75%, and the shift out of agricultural
employment has led to urbanization. Many countries are now in the process of this shift. Coupled with the
overall population growth, the increasing rural-to-urban migration causes infrastructure, health, housing, and
transportation problems.
In order to appreciate how and why current industry has been developed and how it affects the
environment, it is important to look at the historical development of industry.
While important technological innovations can be identified in earlier historical periods, the most impor-
tant ones that significantly influence the environment took place in the eighteenth century. The rise of industry
as we know it today began with the textile industry in the UK, which led to mechanization and factory systems
by the 1820s. Steam power also started in England, led to powerful mechanized industries, and spread quickly
to other countries, reaching to its apex in the 1870s to 1920s. In this period, innovations combined with ac-
cumulation of knowledge and social transformations reinforced one another to drive the industrial revolution.
During the industrial revolutions there were three main tendencies operating: (a) substitution of machines for
human effort and skill on large scales, (b) substitution of fossil fuels for animal power, which greatly increased
the available power, and (c) the use of new and abundant raw materials.
Fueled by coal, heavy industries (e.g., steel production) dominated industry between the 1850s and the
1940s. During this period other technologies such as petrochemicals, synthetics, radio, and electricity emerged.
In the 1920s mass production and consumption technology started, and it continues to the present time. The
mass production techniques, together with scientific management styles, resulted in an increase in productivity
and efficiency by means of economies of scale, and the emergence of multinationals operating on the global
level. Railways have been replaced by roads and the internal combustion engine vehicles; air transportation
and communication networks (radio, telephone, TV, Internet) have overcome physical distance and enhanced
cultural and information exchange. All these have led to changes in social values, new technologies, and
new ways of organizing production, thus shifting occupational profiles and encouraging global competition.
This period can be characterized by an unprecedented increase in many different products for consumers.
Also, higher productivity and consequent increased resource use resulted in higher incomes and reduction in
working hours, in turn leading to more consumption (and more waste) and an increase in leisure and travel
time, whence more energy use and more emission.
In the new millennium the mass production–consumption era still continues strongly. The environmental
impacts of this era are significant in that it generates wastes and pollutants of whose long-term effects we re-
main ignorant. The number of new materials and substances introduced over the last 50 years is large. Plastics,
composite materials, pesticides, drugs and vaccines, and nuclear isotopes are just a few of the major ones. The
properties, functions, and services these new products provide are spectacular. Penicillin and other antibiotics
have almost wiped out a large number of infectious diseases and significantly increased life expectancy. Plastic
containers and packaging have improved hygiene and food preservation. New materials such as alloys and
ceramics have found many diverse applications.
Today, industrialization is at the core of global change. Because of the success of industrialization, artificial
transformations of matter and energy have assumed global dimensions. Industry mobilizes about 20 billion
tons of materials annually in the form of fossil fuel, minerals, and renewable raw materials. The extraction,
conversion, and disposal of these quantities produce 40 billion tons of solid wastes per year. In comparison,
total materials transport by natural river runoff is about 10 to 25 billion tons a year. In addition to quantity,
quality also matters. For example, release of less than one ton per year of dioxins and furans is responsible for
major human health and environmental concerns.
An emerging and important technological sector, which is likely to dominate human behavior
and environmental impacts of technology in the near future, is the services and information industry. In it,
the consumption activities are decentralized and driven by complex motivational structures. Its constraints
are no longer dependent only on the natural and economic resources and technological limitations, but also
on human activities. In industrialized countries, the service sector typically accounts for about two-thirds
of economic output and employment. In the United States the service sector provides 72% of employment.
Studies in the the United States indicate that growing categories in the service sector will be largely in health,
virtual reality media (telephone, audio, video, computers), and recreational services, approaching about 40% of
personal incomes. Previously, services were regarded as low-tech activities, but they are now large consumers
of new technologies, particularly information and communications technologies (4).
Technology and Economics.
Most societies in recent human history have sought to increase their level
of economic activity through economic growth and increased capacity to provide goods and services. Economic
growth requires inputs and greater consumption of resources; it accelerates the flow of matter and energy
through the society to produce outputs (Fig. 3). As discussed above, technology helps this economic growth;
hence technology and economics are closely related and can be treated with macroeconomic or microeconomic
models. The main drivers of this relation are population, demography, income levels and living standards, and
resource use (5).
Since the onset of the industrial revolution in the middle of the eighteenth century, global industrial
output and productivity have risen spectacularly. Data offered by various researchers indicate that global
industrial output has risen by approximately a factor of 100 since the 1750s. Over the last 100 years, output
has grown by a factor of 40, an average growth rate of 3.5% per year. Per capita industrial production has
increased by a factor of 11, equivalent to a growth rate of 2.3% per year. Taking the United Kingdom as an
example, the average number of hours worked in a lifetime in 1956 was estimated to be about 150,000 for
men and about 63,000 for women. In 1981 it was estimated to be about 88,000 for men and 40,000 for women,
signifying a 40% drop for men and 37% for women (4).
Over the last 100 years, real wages in industry have risen by more than a factor of 10, and working time
has fallen by a factor of 2, thus bringing affluence and leisure. Material productivity and energy productivity
have also risen sharply. Producing a ton of steel requires only one-tenth of the energy input that it required
about 100 years ego. Higher productivity and more output have enabled higher wages and shorter working
hours; both are important elements of consumer societies. Higher consumption is the necessary counterpart to
Fig. 3. Human economic activities lead to growth and prosperity. But the growth requires greater consumption of natural
resources. Use of natural resources throughout human society leads to many environmental effects such as air and water
pollution, land degradation, and climate changes.
Fig. 4. The population growth, increase in incomes, and higher standards of living through the use of technology lead to
many environmental changes. The intensity of environmental impact of technology and population can be expressed by a
simple formula I=PAT,whereIis the environmental impact, Pis the population, Ais the affluence factor, and Tis the
damaging effect of technology.
higher production of the industrial sector. At the same time, new environmental concerns have emerged at the
local and global levels. For example, synthetic substances are depleting the ozone layer and are increasing the
concentration on the greenhouse gases, causing global warming.
Technology, Population, and Environment. The relation between environmental changes, popula-
tion, and economic growth is important, since environmental damage can be directly related to the growth and
location of world’s population. Clearly, more people require more food, more space, more fuel and raw materials.
Environmental damage can be associated with population, per capita income, the gross domestic product, and
so on; see Fig. 4. At the same time, an improved standard of living is a critical need for a substantial portion of
the world’s population. As a result, the key issue is not whether there should be additional growth, but rather
how to achieve without thwarting important social, economic, and environmental goals.
Information on population size and growth is of fundamental importance for evaluations of environmental
change (5). Data on the distribution and age structure of a population is a prerequisite for the assessment and
prediction of its environmental, socioeconomic, and health problems. The world population increased from
about 890 million in 1750 to 3 billion in 1960 and 6 billion in 2000. The population has been increasing rapidly
since 1970s (1.7%/year), particularly in developing countries, due to increased life expectancy and the number
of births exceeding the number of deaths.
Today, the distribution of the world population of 6 billion is as follows: 59.4% in Asia, 4.7% in North
America, 8.5% in South America, 13.8% in Africa, 8.2% in Europe, 0.5% in Oceania, and 4.9% in the former
Soviet Union. Overall, the population in the industrialized countries is about 20%, and in the developing
countries 80%. Although there are disagreements and variations in the estimation of future population from
one to another source and from one to another year, the UNPD and World Bank estimate that world population
will reach 8.5 billion by 2030 and will be just under 12 billion by 2050. About 90% of the world population
increase is in the low-income nations of Africa, Asia, and Latin America, where in 42 countries the growth
rate exceeds 3%. In 48 countries, mainly in Europe and North America, the growth rate has stabilized at less
than 1%. By the year 2030 the distribution of the world population will change considerably: 57.8% in Asia,
3.9% in North America, 8.9% in South America, 18.8% in Africa, 6.1% in Europe, 0.4% in Oceania, and 4.1%
in the former Soviet Union. The population in the industrialized countries will be about 15.9%, in developing
countries 84.1%. For more information on population see the Annual Report of the German Advisory Council
on Global Changes, 1995 (8).
One of the important environmental problems is due to rapid urbanization, which has resulted in the
formation of cities and megacities. In 1800 less than 3% of the world’s population was living in cities with
20,000 or more inhabitants; now this percentage is more than 40%. Global urbanization is set to continue, with
increasing tempo in the developing world. It is estimated that more than 80% of the population in developed and
more than 50% in developing countries will live in urban areas by the year 2025. The annual average growth
rate of the urban population is about 2.7% per year. This continuing expansion presents many environmental
problems and requires the provision of basic services such as water supply, sanitation, housing, transport,
and health services. Particularly where squatter settlements proliferate on the outskirts of cities, a common
occurrence in developing countries, access to drinking water and sanitation facilities may be inadequate or
entirely lacking. Rural populations in many developing countries have very poor access to safe water.
Cities will play a crucial role in the world in the new millennium. Despite their seeming insignificance in
terms of area (only around 0.3% of the earth’s surface), they have vast effects on the regional and global scales.
Many cities, accommodating over 1 billion people, are built on coasts, rivers, and estuaries. Because of these
locations, large pollution loads in both air and water transport the effects of urban activities over long distances.
Cities also cause major alterations to topography, drainage systems, climate, economies, and social systems.
For example, while photochemical smog affects the local urban population’s health, damage to vegetation from
high concentrations of troposphere ozone is a regional problem, as is the destruction of forests and lakes from
acid rain; burning fossil fuels for industrial and domestic energy, largely in urban areas, contributes to the
intensification of pollution and enhances the greenhouse effect.
Moreover, in parallel with the predicted increase in population, global per capita income is estimated to
increase by over 80% between 1990 and 2030, and developing-country per capita income may grow by 140%. As
a result, by 2030 world economic output could be as much as 3.5 times its present value. If the environmental
impacts rose in step with these projected developments, the result would be detrimental to environment and
humans. Nevertheless, the intensity of damage can be reduced through existing technologies and approaches
that make more efficient, sustainable use of resources, such as energy conservation, recycling, and more efficient
and cleaner industry.
Assessing and Controlling of the Effect of Technology. As indicated earlier, technology affects
the environment through human behavior. The effects need to be monitored, measured, and interpreted in
a scientific manner. One approach to evaluating the effect of technology is modeling. Both conceptual and
mathematical approaches are available for modeling technological impacts on environment (9). Nonetheless,
the modeling is only a first step toward a good understanding of the process. There is always uncertainty on
many issues such as future technological configurations, their social acceptability, and their environmental
implications. In the absence of deterministic models, empirical base patterns are used to determine the effect
of technology on the environment (4). Empirical observations indicate that technological change is continuous,
pervasive, and incremental. Technological impacts on the environment are ubiquitous in space and time, across
different technologies, and across societies, being shaped by what and how societies produce and consume, and
how they interact with the environment (10).
Indeed, efforts to solve environmental problems can only be successful when based on sound understand-
ing and reliable data (11). Regrettably, although there are increasing number of published environmental
compendia of various types, a comprehensive coverage of many regions of the world still is not available.
Here, technology helps by providing better data on environment and human activities, and giving powerful
means of analyzing the data to build models and management plans. For this purpose accurate environmental
instruments and instrumentation will help to increase the amount of reliable information available.
Despite the growing number and efforts of environmental monitoring programs, significant gaps in na-
tional and international environmental statistics still exist, due to differences in definitions and lack of un-
derstanding of the significance of the problems in many nations. Nowadays, conventional monitoring methods
have been complemented by observations from satellites specifically devoted to earth resources monitoring
(11). The main advantages of satellite sensing are the provision of repetitive and large-scale data in remote
and/or inaccessible regions. There are, however, some disadvantages to satellite monitoring that still have to
be overcome, particularly technical limitations of sensors. Nevertheless, satellite remote sensing now has a sig-
nificant role in mineral and land resource monitoring, agriculture, forestry, water resources, natural disasters,
and other environmental fields.
It is worth noting that in recent years, there has been substantial investment in the global market for
environmental goods and services (5), a list of some companies is given in Table 1. The Organization for
Economic Cooperation and Development (OECD) estimates that the global market for environmental services,
combined with pollution control and waste management equipment and goods, stood at about US$300 billion
in 2000.
The most general and important strategies to lessen environmental impacts of technology center on
improving land, energy, and labor productivity. Governments, individuals, firms, and society at large spend
resources on innovation, experimentation, and continual improvement. Other strategies center on specific
technologies to reduce particular environmental impacts by fitting them with cleanup technologies. Still other
strategies focus on radically redesigning the production process and the entire product cycle.
International Cooperation on Environmental Issues. Attempts at international cooperation on
environmental and resource management issues began in the late nineteenth century, mainly on regional
rather than global issues. Many dealt with regional fisheries or ocean pollution, or international waterways.
Today, there is a very wide scope of activities relating to environmental management in which cooperative action
is effective, beneficial, and even essential for control or solution of environmental problems on national and
international levels, as illustrated in Fig. 5. These activities, conducted within local areas, nations, and regions
and globally, include information collection and dissemination, regulation setting and control, collaborative
research, and monitoring to protect the environment and preserve natural resources. Organizations such as the
United Nations (UN), the OECD, Council of Mutual Economic Assistance (CMEA), the European Community
(EC), the Association of South East Asian (ASEAN), and the Organization of African Unity (OAU) have branches
to look after environmental concerns. Established nongovernmental organizations, including the International
Union for the Conservation of Nature and Natural Resources (IUCN) and the International Council of Scientific
Unions (ICSU), also play a major role in environmental concerns.
The UN Conference on the Human Environment, held in Stockholm in 1972, was the first international
conference to have a broad agenda covering virtually all aspects of environmental concerns. One of the most
important outcomes of this conference was the establishment of the United Nations Environment Program
(UNEP) in 1974. Its major tasks were to act as a source of environmental data, assessment, and reporting on
a global scale, and to become a principal advocate and agent for change and international cooperation.
UNEP has been working in close collaboration with the UN and outside organizations to establish and
promote a large number of programs covering such topics as desertification, climate change, hazardous wastes,
oceans, and global environmental monitoring. In 1980, UNEP, in conjunction with the World Conservation
Fig. 5. Today, humans realize that the environment is fragile and can no longer be used in the traditional way. Therefore,
many organizations at various levels are looking into environmental problems and means of sustainable development.
Union (IUCN) and the World Wildlife Fund (WWF), produced a World Conservation Strategy that contained
key features for sustainable development. The United Nations Conference on Environment and Development
(UNCED), held in Rio de Janeiro in 1992, was a comprehensive meeting and a major media event that
focused worldwide public attention on environmental issues; its agenda is given in Fig. 6. Although there was
disagreement on many issues, UNCED initiated many international actions to be taken and organizations to be
set up concerning regional and global environmental problems. The Montreal Protocol of 1994, the Convention
on the Law of the Sea (1994), the Desertification Convention, and the Biodiversity Convention are some of the
important milestones in international cooperation on environmental issues (8).
Since 1957, a network of data centers, operating under the auspices of ICSU, has provided facilities for
archiving, exchange, and dissemination of data sets, which now encompass all disciplines related tor the earth,
its environment, and the sun. Currently there are 27 World Data Centers (WDCs) active, each tending to
specialize in one discipline. The United States maintains nine WDCs, Russia two, and 16 other centers operate
in various countries. There are other important organizations such as International Environmental System
(known as INFOTERRA) and the International Register of Potentially Toxic Chemicals (IRPTC). Nowadays,
environmental data are obtained from a wide variety of sources and in many formats, including satellite
observations, using advanced computer technology. The data entered in the Global Resource Information
Fig. 6. The United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro in 1992, was
very significant in bringing people of the world together on environmental issues. As can be seen, the conference agenda
included many important economic, social, management, and implementation issues, thus providing the basis for a good
understanding of environmental problems.
Database (GRID), maintained by the UN, are analyzed and integrated using Geographic Information System
and image-processing technologies to describe complex environmental issues.
Specific Effects of Technology
Land Use. Three major cultivation centers are recognized historically: in southeast Asia as early as
13,000 B.C., the Middle East about 11,000 B.C. with irrigation about 7000 B.C., and Central America about 9000
B.C. Since then, human-induced land degradation has been taking place in many forms, such as soil erosion,
salination, desertification, waterlogging, soil acidification, soil contamination, and range-land degradation.
Throughout history, man has substantially altered much of the world’s land cover by clearing forests and
draining wetlands for agriculture and livestock, burning grasslands to promote desirable forage crops, and
building villages, towns, and cities for human habitation. Generally, the impact on land and the changes in
land use have presented problems when the decisions of a sufficient number of users or owners coincided. Thus
land usage has been a cumulative phenomenon (12).
Land use can be divided into three broad categories: agricultural lands, forests and woodlands, and other
lands (cities, unmanaged rangelands, wetlands, etc.). We will briefly discuss them here.
Since the 1930s, global agriculture has been transformed from a resource-based industry
to a technology-based industry. Mechanization, synthetic factor inputs in the form of fertilizers and pesticides,
new production techniques, biological innovations, and new crops have pushed agricultural output to large
scales, thus requiring fewer farmers. The reduced demand for farmers is followed by migration from rural
to urban areas. At the same time, progress in agricultural technologies and techniques has progressively
decreased the need for expansion of arable land to be able to supply food for increasing population. Initially,
Fig. 7. Carbon, nitrogen, sulfur, and phosphorus are naturally cycled in the ecosystem. However, man’s activities accel-
erate and upset this natural cycle, thus adversely affecting air, soil, and water.
this decrease slowed down the expansion of agricultural land in some countries, transferring the expansion to
others. Particularly in European countries and the United States, agricultural productivity increased to such
an extent that some agricultural land could be converted to other uses. In recent years, agricultural mass
production, combined with saturation of the demand for food, has translated into absolute reductions in the
overall agricultural land requirements around the globe. Here, technology has tended to spare nature and
the environment. But, in parallel with the decreased land requirements, the overall expansion of agricultural
production had other effects, such as putting pressure on water resources and affecting global nutrient and
geochemical cycles (12).
Important factors in agriculture are land, labor, energy, water, and nutrients. In some areas agricultural
systems are highly land-productive and labor-intensive, as in Asia; in others, labor-productive and land-
intensive, as in North America and Australia.
In land-intensive areas, in order to raise land productivity, many synthetic fertilizers (e.g., superphos-
phates and nitrogen fertilizers) have been widely used. For example, after the Second World War ammonia
synthesis became the dominant source of nitrogen fertilizers, and since then global nitrogen use has risen from
3 million tons to over 80 million tons. The use of phosphates has risen to over 150 million tons. Today, artificial
nitrogen and phosphate cycles affect nearly every major biospheric flow of nitrogen and phosphorus nutrients
on the planet (Fig. 7).
Pesticide use has also grown significantly, to a production level of over 3 million tons of formulated
pesticides per year. The adverse environmental effect of long-lived pesticides, such as DDT, has been significant
globally. Nevertheless, there has been important progress in the development of degradable pesticides.
Innovations in food preservation have proved to be very important. These began with tin cans, concen-
trated milk, and refrigeration. The refrigeration technology remained cumbersome until the 1930s, suffering
from frequent leaks of reactive ammonia. To solve that problem, chemically inert chlorofluorocarbons (CFCs)
were substituted, which contributed significantly to the depletion of the earth’s stratospheric ozone layer (3).
Agricultural production suffers from crop pests and diseases. Adverse impacts are caused directly, such
as by insect defoliation or by competition for space, light, and nutrients by weed species, or indirectly, by
vector organisms carrying crop diseases. The use of pesticides has helped to reduce crop losses. However,
adverse environmental effects, such as pest resistance and food-chain accumulation, have forced us to phase
out several of the more toxic and persistent chemicals.
Apart from crops, livestock are maintained for meat, milk, eggs, wool, leather, and transportation. World-
wide, the numbers of some livestock have increased significantly while others have declined. In many dryland
areas, irrigation has been essential to maintain adequate grassland for livestock. However, badly managed
irrigation has caused salt accumulation on the soil surface as water evaporated, leading to salinization, which
has become a significant environmental hazard and a chronic problem in many parts of the world, as in the
case of Australia.
Forests and Woodlands.
Forests are perhaps the most important biomass on the earth; they play vital
role in the planet’s biophysical system. They are reservoirs of biodiversity and habitats for endangered plant
and animal species. Yet, they are also among the most threatened environments, being depleted at rate that
could reduce them to impoverished remnants within decades. Technology in the form of powerful machinery
and easy transportation, together with increase in the human population and demand for forest products such
as paper and timber for housing and fuel, accelerates deforestation (10).
Forests and woodlands account for more than one-fifth of the world total land area (8). Forests are
under pressure on account of many human uses: agricultural land, firewood, marketable timber, and land for
settlements. The loss of forests and woodlands has varied considerably between countries, and the recent data
indicate a general increase in clearing of forests for cropland or pasture in developing countries since the 1960s.
However, many developed countries have increased their forested area and reduced the area of cropland (12).
The first complete assessment of forest cover was estimated in 1990 by the Food and Agricultural Organi-
zation (FAO). According to various sources (e.g., Ref. 4), the green areas of the planet in 1980 were as follows: 51
million km2(38%) covered with forests, close to 70 million km2(51%) with grass, and 15 million km2(11%) with
crops. In the forest land, there was estimated to be 34 million km2of native tree species and plantation forests,
and the remaining 17 million km2consisted of other woody vegetation such as open woodland, scrubland, and
Increase in land use and deforestation has had significant effects on the environment through altered
ecosystems, destroyed wildlife habitats, changed regional climates, and the release of an estimated 150 billion
tons of carbon into the atmosphere. The FAO defines deforestation as the conversion of forest to other uses
such as cropland. By this definition, the forests declined by 2% between 1980 and 1990. But in the same period,
new plantation cover totaling to about 630,000 km2offset the loss of natural forest. At this point credit must
be given to China for her massive forestation programs.
The land use changes associated with forests are the ones of greatest significance to the global climate
system. Deforestation for agricultural and other uses is one of the major causes of increased atmospheric carbon
concentration and the ecological problems facing the planet (2). The ecological environmental consequences
of deforestation include soil erosion, incapacity of soil to retain water, loss of biological diversity, and loss of
cultural diversity. Loss of forests and change in land use for other purposes results in significant emissions of
CO2and other greenhouse gases.
Deserts are arid areas with sparse or absent vegetation and a low population density. Together
with semiarid regions, they constitute more than one-third of the earth’s surface. However, only 5% of the
earth’s land surface can be described as extremely arid. Such regions include the central Sahara and the Nabib
deserts of Africa, the Takla Makan desert in central Asia, the Atacama Desert in Peru and Chile, parts of
the southwestern United States and northern Mexico, the Gobi desert in northeastern China, and the Grate
desert of Australia (12). It has been observed that more than 100 countries are suffering the consequences of
desertification, or land degradation in dry areas.
In addition, the ice deserts of the Antarctic continent and the Arctic region should be mentioned. They are
fairly barren with respect to fauna and flora. A vast ice sheet, averaging about 2000 m deep, covers Antarctica’s
14,200,000 km2surface. The cold climate of Antarctica supports only a small community of plants, but the
coasts provide havens for seabird rookeries, penguins, and Antarctic petrels. Research findings indicate that
there has been a large-scale retreat of Antarctic Peninsula ice shelves during the past 50 years due to local and
global warming.
Land Use for Human Occupation and Residence.
Reference to technology’s impact on land use usually
calls up misleading images of land covered by cities, sprawling suburbs, factories, roads, dams, pipelines, and
other human artifacts. In reality, the area covered by these is most likely less than 1% of the earth’s total land
area. It is estimated that globally 1.3 million km2of land (1%) is built up. Physical structures like buildings
and infrastructures are estimated to cover not more that 0.25 million km2, or less than 0.2% of the global
land area. However, these small percentages mask potentially serious land-use conflict over usable land, as
settlements impinge on agricultural and forested areas (10). Also, the land that urban structures occupy is
almost permanently excluded from alternative uses.
Urban infrastructures such as water systems offer greater efficiency, thus improving environmental
conditions. Nonetheless, there is substantial urban poverty around the world and, with it, urban environmental
stress. Large urban population concentrations also create environmental stress, such as smog, and serious
health hazards. Urban poverty remains widespread; over the globe, more than 1 billion urban people have no
access to a safe water supply. Some 2 billion people lack adequate sanitation. These constitute a prime example
of environmental problems arising from too little technology rather than too much. Urban environmental
problems due to high population concentrations are most noticeable in air and water pollution. The large
appetite of cities for water strains resources significantly (12). This strain is felt differently in different places.
For instance, in Mexico City water comes almost exclusively from a local aquifer, and its depletion causes
significant land subsidence. Another example is Venice, where heavy groundwater withdrawal for industry has
led to subsidence of nearby areas and flooding of the city.
Soil Contamination. Soil contamination refers to addition of soil constituents, due to domestic, in-
dustrial, and agricultural activities, that were originally absent in the system. Soil contamination is of two
different kinds. One is the slow but steady degradation of soil quality (e.g., organic matter, nutrients, water-
holding capacity, porosity, purity) due to contaminants such as domestic and industrial wastes or chemical
inputs from agriculture. The other is the concentrated pollution of smaller areas, mainly through dumping or
leakage of wastes. The sources of contamination include the weathering of geological parent materials, where
element concentrations exceed the natural abundances in wet or dry deposition forms (2).
Soils are prone to degradation due to human influences in a number of ways: (1) crops remove nutrients
from soils, leading to chemical deterioration, (2) management practices influence soil quality through waste
dumping, silting, and salinization, and (3) erosion removes soil. There are many examples of such degradation,
and the impacts that it inflicts on the environment have been witnessed around the globe since antiquity. For
instance, silting of soil due to bad irrigation practices destroyed the agricultural base of the large empires of
Mesopotamia. Recently, in the United States in the 1930s, due to destructive agricultural practices, drought
and dust storms caused dust bowls carrying millions of tons of fertile topsoil hundreds of miles, thus forcing
millions of farmers to abandon their lands.
A number of metals and chemicals are commonly regarded as contaminants of soil. They notably include
heavy metals, but also include metalloids and nonmetals. The main elements implicated as contaminants are
arsenic, cadmium, chromium, copper, fluorine, lead, mercury, nickel, and zinc. In addition, beryllium, bismuth,
selenium, and vanadium may also be dangerous (2).
Acid deposition arises largely through complex chemical transformation of sulfur and nitrogen oxides in
the atmosphere and the resulting acidification of the environment. Many environmental effects of it, including
soil and freshwater acidification, injury to vegetation, and materials damage, are well documented. Until
recently, recognition of the problem of acidification has been confined to acid-sensitive regions of North America
and Europe. However, many other regions are likely to be affected if trends in population growth, urbanization,
and energy consumption continue.
At this point acid rain must be elaborated on, as it is one of the prime cases of acid land degradation.
Acid rain refers to the acidification of rain associated with the combustion of fossil fuels: coal, oil, and natural
gas. The constituents of flue gases that contribute to the acidity of rain are oxides of sulfur and of nitrogen.
These chemical compounds react with the water vapor to form acids. Some acids may adhere to particulates in
the air to form acid soot; most are absorbed by rain, snow, or hail and carried far from the source of pollution.
Significantly affected areas are the northeastern United States; Onterio, Canada; Scandinavia; and the Black
Forest in Germany.
Sediments provide an integrated assessment of contamination within a body of water. The levels of
contaminants in sediments are often higher than in the water itself and thus easier to analyze. Sediments in
lakes, in particular, are suitable for contaminant monitoring, as they often remain undisturbed for many years
and represent an accumulation of suspended material from the whole lake basin. They can therefore reflect
the integrated effects of human activity in the surrounding area. Since many metals and organic substances
have an affinity for organic matter or mineral particles, both soils and sediments are suitable media for the
accumulation of contaminants from the aqueous sources and atmospheric deposition. Studies, particularly in
lake sediments, enable historical records of many contaminants to be obtained.
Waste materials are one of the major factors in degradation of soil. Nowadays, many environmental
problems come from population concentrations generating large amounts of solid, liquid, and gaseous waste,
exceeding the assimilative capacity of the environment. Globally, total solid and liquid urban wastes amount
to approximately 1 billion tons per year. Over the 200 years since the beginning of industrialization, massive
changes in the global budget of wastes and critical chemicals at the earth’s surface have occurred, challenging
natural regulatory systems that took millions of years to evolve.
Waste products can be classified as municipal wastes, wastewater, wastes dumped at sea, oil and oil
products, hazardous waste, and radioactive effluent. Municipal wastes and wastewater originate from domestic
and industrial sources as well as urban runoff. There are still a few countries and cities that dump wastes into
the sea, in violation of the London and Oslo conventions. Waste and spilled oil often end up in surface waters
and the sea. The total input of petroleum hydrocarbons to the marine environment is difficult to estimate; the
main contributors are from river runoff, the atmosphere, and spills from oil tankers.
Production of toxic and other wastes continues to grow in most countries, and data indicate that disposal
of these wastes is already a significant problem or will become one in the near future. However, implementation
of educational programs, collection schemes, and new technologies has caused an increase in the quantities
and variety of materials being recycled. Increased public awareness of waste issues has also resulted in
some governments funding research into new methods of waste reclamation, recycling, and disposal, and of
implementation of regulatory measures (2).
Toxic and Hazardous Wastes. Toxic materials (some heavy metals, pesticides, chlorinated hydrocar-
bons, etc.) are chemicals that are harmful or fatal when consumed by organisms even in small amounts. Some
toxic materials may be deadly even at concentrations in parts per trillion or less. The toxic pathways through
the living organisms are governed by absorption, distribution, metabolism, storage, and excretion (3). Toxic
effects can be acute, causing immediate harm, or chronic, or long-term harm. For example, pesticides (e.g.,
DDT) can cause cancer, liver damage, and embryo and bird egg damage; petrochemicals (e.g., benzene, vinyl
chloride) cause headaches, nausea, loss of muscle coordination, leukemia, lung and liver cancer, and depression;
heavy metals (e.g., lead, cadmium) can cause mental impairment, irritability, cancer, damage to brain, liver,
and kidneys; and other organic chemicals such as dioxin and polychlorinated biphenil (PCBs) can cause cancer,
birth defects, and skin disease.
Toxic substances are generated mainly by industry, either as primary products or as wastes (2). Over the
times, technologies have drawn on different principal raw materials and different energy sources, ranging from
iron and coal in the nineteenth century to plastics, petrochemicals, oil, and natural gas in the twentieth. Hence
the amounts and compositions of wastes have varied in time. For example, in 1990 the US chemical industry
produced some 90 million tons of organic and inorganic chemicals. To produce these chemicals it generated 350
million tons of wet hazardous wastes.
It must be mentioned here that the term “hazardous materials” has different definitions in different
countries. Depending on the definition, estimates for the United States vary from 100 million tons to 350
million tons, including 329 chemicals.
Hazardous wastes are generated in great amounts. Important hazardous wastes are: waste oil, acids,
alkalis, solvents, organic chemicals, heavy metals, mercury, arsenic, cyanides, pesticide wastes, paints and
dyes, pharmaceutical, and others. Landfill, incineration, and dumping at sea are currently the most used
disposal methods for hazardous wastes. Elimination, transportation, and dumping of hazardous wastes can be
a socially and politically sensitive issue; therefore complete worldwide data are not available. In some cases,
these wastes are internationally traded. International transportation of hazardous waste can be divided into
two classes: transportation to a recognized location for authorized treatment or disposal, and importation to
be dumped illegally.
US laws regulating hazardous wastes are very strong compared to most countries’. While many European
countries have laws similar to the Resource Conservation and Recovery Act (RCRA) of the United States,
none is as restrictive and comprehensive. For example, the United States lists approximately 500 wastes as
hazardous; the United Kingdom, 31; France, 100; and Germany, 348. One estimate suggests that only 20% of
Italian toxic waste is disposed of properly, with the rest either stockpiled, dumped illegally, or exported. The
difference between the US hazardous waste laws and those in developing countries is even greater. Few of the
latter have significant laws regulating hazardous wastes.
Another hazardous waste of importance is the radioactive waste that is generated by the reprocessing of
nuclear fuel and discharged in liquid effluent. Contamination levels of discharges are measured in terms of the
long-lived nuclides 90Sr, 137Cs, and 106Ru, and selected isotopes of transuranic elements.
Water Pollution. Water is a resource fundamental to all life, and it is important in both quantity and
quality, particularly for humans. Fresh water is essential for life, and clean, unpolluted water is necessary to
human health and the preservation of nature. Water usage varies from one country to another. In 1940, total
global water use was about 200 m3/capita·yr. The global use of water doubled in the 1960s and doubled again
in the 1990s to about 800 m3/capita·yr. According to the World Bank, the United States uses 1870 m3of water
per person per year, Canada 1602 m3, and other developed countries about 205 m3on the average. In last 20
years, growth of water use has flattened in developed countries because of technology improvement in response
to water laws.
Water is used for many purposes besides human consumption, and in arid and semiarid countries large
quantities are used for irrigation. The water availability varies from one country to another; for example avail-
ability is 110 thousand m3/capita·yr in large and sparsely populated Canada, and 0.04 thousand m3/capita·yr
in Egypt, which receives most of its water from other countries. The internal renewable water resources in
Bahrain are practically nil. Also, countries with rivers that have already passed through other countries may
suffer from reduced quantity and quality as a result of prior use upstream.
Throughout the world, agriculture uses approximately 2000 km3of water annually for irrigation and
livestock. Households, services, and industry use about 1000 km3. Since the industrial revolution, irrigation
water usage has increased by a factor of 30, causing significant environmental impacts. Irrigation is the key
technology for increasing agricultural productivity and yields. Only about 16% of the global cultivated land is
irrigated, but that 16% produces approximately 33% of all crops. The central components of irrigation systems
are the reservoirs, which are just over 30,000 in number, covering 800,000 km3and holding 6000 km3(6000
billion tons) of water worldwide. Prior to 1900, reservoirs globally held only about 14 km3of water. This increase
in the volume of water captured in reservoirs, which is about 450 times within a century, has been the largest
material-handling effort of mankind.
Water withdrawal for irrigation purposes can have a number of ecological impacts far beyond the agri-
cultural ones. Perhaps the most dramatic illustration in this century is the disappearance of the Aral Sea,
resulting in severe ecological consequences such as salinity, destruction of the fish population, and serious
health problems for the local population, including an increase in infant mortality.
Water Quality Problems.
Different standards of water quality are acceptable for different uses. Water
for human consumption should be free of disease-causing microorganisms, harmful chemicals, objectionable
taste and odor, unacceptable color, and suspended materials. In contrast, stock can tolerate saltier water,
irrigation water can carry some sediments, and so on. As a general principle, water quality problems fall into
two categories, biological and chemical (2):
Biological agents such as bacteria, viruses, and some higher organisms can exist naturally or can be human-
induced. They can cause infections and outbreaks of acute diseases. Microbiological contamination of water
is responsible for many widespread and persistent diseases in the world. Globally, around 250 million new
cases of waterborne diseases are reported each year, resulting about 10 million deaths, 60% of which are of
Chemical agents such as suspended sediments, toxins, and nutrients are generated by various forms of
land use, industrial and agricultural activities, wastes, and air pollution.
Many pollutants, through terrestrial runoff, direct discharge, or atmospheric deposition, end up in surface
waters. In turn, rivers carry many of these pollutants to the sea. However, water quality varies from one
location to the next depending on local geology, climate, biological activity, and human impact. Several basic
measurements of natural water quality need to be made before the additional impact from artificial sources
could be assessed. With increasing numbers of chemicals being released into the environment by man, the
number of variables that may have to be monitored in both fresh and marine water is growing all the time,
and is currently in the hundreds. Nonetheless, subnational governments set the standards on water pollution;
therefore it is difficult to obtain data and compare water regulations between nations. Also, water controls in
many jurisdictions are very weak.
One of the major causes of water pollution is due to cycles of nitrogen and phosphorus, as shown in Fig. 7.
The first inorganic nitrogen fertilizer was introduced in the nineteenth century in the form of Chilean nitrates
and guano, but the real breakthrough came early in the twentieth century with ammonia synthesis using the
Haber–Bosch process. Overall, human activity has doubled the rate of global nitrogen fixation since preindus-
trial times, and farming has largely become dependent on assuring adequate nitrogen supplies. The resulting
large increase in nitrogen mobility creates environmental concerns. Nitrates can pollute underground water
resources, and NOxemissions from combustion are a major cause of urban photochemical smog. Ammonia
(NH3) emissions from fertilizer application and from dense livestock populations add to nitrogen oxides as
an additional source of acidification. In the mid-1990s, European nitrogen emissions totaled some 13 million
tons of elemental nitrogen. About half of this came from agriculture, 4 million tons were emitted from mobile
sources such as vehicles, and 3 million tons from stationary sources. Also, nitrogen in the form of N2O con-
tributes substantially to the global greenhouse effect (3). The N2O is highly absorptive in the infrared, and its
atmospheric residence time is approximately 120 years.
Rivers, lakes, underground waters, and marine waters around the globe face somewhat different threats
from technology and human activities. The most important pollutant in rivers are eroded soil, salt, nutrients,
wastewater with high organic content, metals, acids, and other chemical pollutants. As far as lakes are con-
cerned, an important environmental concern is the problem of eutrophication, that is, enrichment in nutrients.
In the recent decades, extensive use of fertilizers that run off from agricultural land and the discharge of
wastewater into rivers have aggravated this problem.
The underground waters, on the other hand, suffer from dumping of wastes and from agricultural activi-
ties. Underground water is an important source of drinking water in both developing and developed countries.
It accounts for 95% of the earth’s usable fresh-water resources and plays an important part in maintaining soil
moisture, stream flow, and wetlands. Over half of the world’s population depends on underground water for
As a result of the long retention time and natural filtering capacity of aquifers, these waters are often
unpolluted. Nevertheless, recently, there has been evidence of pollution from certain chemicals, particularly
pesticides. In some countries the use of pit latrines has led to bacterial contamination of drinking-water wells
through underground water movement. Increased nitrate levels in ground waters cause concern in many
developed countries. One of the most widespread forms of groundwater pollution is an increase in salinity,
often as a result of irrigation or saline intrusion in coastal areas and islands.
Water quality in seas is particularly important in regard to the contamination of fisheries. There is
evidence that a general deterioration of water quality in highly exploited seas is taking place, causing serious
concerns. There are many examples showing the adverse effects of technology and human behavior on water
quality, affecting vast areas and vast volumes of water. In addition to the Aral Sea, one may mention the Baltic
Sea and the Caspian Sea.
The Baltic Sea.
The Baltic Sea covers 420,000 km2and is fed by four major rivers. It is the largest area
of almost fresh water in the world. Today it borders countries that are home to more than 80 million people
conducting about 15% of the world’s industrial production. Hence, the waters of the Baltic are becoming turbid
due to increased nutrient flows from the land and from the atmosphere. The bottom mud is becoming loaded
with phosphorus. Toxic wastes from industry and transportation systems have greatly reduced the population
of seals, otters, and sea eagles.
The Caspian Sea.
The Caspian sea covers an area of 370,000 km2and is fed by many rivers. There
are some 850 fauna and more than 500 plant species in the Caspian. Due to industrial activities and petrol
production, the fragile Caspian ecosystem is buckling under increasing exploitation, one possible result being
that the world will lose 90% of its caviar production.
Resource Depletion. A resource is a source of raw materials used by society. These materials include
all types of matter and energy that are used to build and run society. Minerals, trees, soil, water, coal, and all
other naturally occurring materials are resources. There are renewable resources (e.g., timber, food, hydropower,
and biomass) that can be replaced within a few human generations, and nonrenewable resources (e.g., ore
deposit metals, and fossil fuels) that cannot (13).
Man is the greatest user of natural resources and consequently presents a major threat to their future
availability. Table 2 illustrates the intensity of common mineral mining and production. Population growth
and rapid development around the world are placing constantly increasing demands on many resources. In
addition, overexploitation and poor management in some areas have led to serious degradation or depletion of
the natural resources on which many lives depend. For example, increased industrial development has placed
continuing demand on the world’s mineral resources. These resources are nonrenewable, and as extraction
continues to increase, methods of recycling have to be investigated to ensure availability of certain essential
minerals for future generations. Consumption of all materials, except mercury and arsenic, has been increasing
steadily. However, some have been replaced by new materials, as in the substitution of plastics for aluminum.
Worldwide, industrial activities with easy availability of supporting technology, such as heavy machinery,
mobilize vast amounts of materials. In 1990s, close to 10 billion tons of coal, oil, and gas were mined as fuel;
more than 5 billion tons of mineral ores were extracted; and over 5 billion tons of renewable materials were
produced for food, fuel, and structural materials. Actual material flows were even higher, because all the
materials mentioned above had to be extracted, processed, transformed and upgraded, converted to the final
goods, and finally disposed of as wastes by the consumers. Globally, metal production generates 13 billion tons
of waste materials per year in the form of waste rock, overburden, and processing wastes. Nevertheless, if
managed properly, most of these materials do not pose environmental problems (13). The overburden, waste
rock, or water is generally not toxic or hazardous.
Technology-dependent metal production and waste-material handling (material mobilization) can signif-
icantly disturb the land, require infrastructures and settlements to be relocated, and substantially alter the
flow of surface and ground waters. The long-term impacts of metal production and waste-material handling
can be remedied through land reclamation and appropriate water management. The extent of environmental
impact depends on the material mobilization ratio (MMR), which is defined as the ratio of final to primary
material (a kind of efficiency). The MMR is nearly 1 in the case of crude oil and petroleum products, but 1 in
150,000 in the case of gold. It can approach to 1 in a million in the case of drugs and medicine.
Metals and hydrocarbons appear to be abundant in the earth’s crust. Accessibility and concentration (both
being functions of technology and price) determine if a particular deposit is minable. The amount of material
input to economies of different countries is difficult to obtain. It is estimated that the total material input to
the US economy in 1994 was about 6 billion tons, or 20 tons/capita·yr. This figure is largely accounted for by
2 billion tons of fuel and 1 billion tons of forestry and agricultural materials, the rest being material imports,
crude oil, etc. In addition, 15 billion tons of extractive wastes are generated, and 130 billion tons of water is
used. The materials used in the United States are mostly hydrocarbons (87%) and silicon dioxide (9%); metals,
nitrogen, sulfur, and other materials constitute the remaining 4%.
Enormous expansion of metal production worldwide has led to emission of copper, lead, zinc, arsenic, and
so on into the environment (13). However, with regard to impacts on the environment, such quantitative data
have to be supplemented with qualitative characteristics of different wastes, most prominently toxicity. For
example, total US dioxin and furan emissions amount only to one metric ton per year, but they cause serious
environmental concern.
As far as resource depletion (Table 2) is concerned, there are several technology-dependent strategies
in place, which can be attributed to environmental impacts. These are (1) dematerialization, (2) material
substitution, and (3) recycling and waste mining. They are briefly discussed below:
(1) Dematerialization is a decrease in the quantity of materials used per unit of output. Computers can be
mentioned as an example; the first electronic computer filled several rooms; today their functions can
easily be performed by small pocket computers. Dematerialization is achieved by radical design changes
and technological change. However, dematerialization of individual items does not indicate decline in the
total consumption of the material that it is made from, since that depends on the volume of production and
(2) Material substitution is a core phenomenon of industrialization. It is possible to show key substitutions
that made technological revolutions throughout the history. In the mass-production–consumption period
the replacement of coal by oil and gas, and of natural materials by synthetic fibers, plastics, and fertilizers,
are good examples. Material substitution overcomes the resource constraints and diversifies key supplies;
it introduces materials with new properties, thus opening new applications and in some cases improving
the functionality of use. In many cases, environmentally harmful materials can be replaced by less harmful
(3) Recycling and waste mining depend on the technology of separation of mixed materials. Many materials
such as aluminum, copper, glass, lead, paper, steel, zinc, arsenic, plastics, and coal ash are recycled for
economic and environmental reasons.
Air Pollution. Air pollution may be defined as unwanted change in the quality of the earth’s atmosphere
caused by the emission of gases and solid or liquid particulates. It is considered to be one of the major causes
of climatic change (greenhouse effect) and ozone depletion, which may have series consequences for all living
things in the world. Polluted air is carried everywhere by winds and air currents and is not confined by national
boundaries (3). Therefore air pollution is a concern for everybody irrespective of what and where the sources
are. Due to the seriousness of air pollution, this article concentrates more on that topic than on others.
The seriousness of air pollution was realized when 4000 people died in London in 1952 due to smog.
In Britain, the Clean Air Act of 1956 marked the beginning of the environmental era, which spread to the
United States and Europe soon after (14). The Global Environmental Monitoring System (GEMS), established
in 1974, has various monitoring networks around the globe for observing pollution, climate, ecology, and
oceans. Concentrations of atmospheric pollutants are monitored routinely in many parts of the world at remote
background sites and regional stations, as well as urban centers. Since the establishment of GEMS, some
interesting findings have been reported. Some examples are as follows: It is found that overall only 20% of
people live in cities where air quality is acceptable. More than 1.2 billion people are exposed to excessive levels
of sulfur dioxide, and 1.4 billion people to excessive particulate emission and smoke. In 1996, there were over
64,000 deaths in the United States that could be traced to air pollution.
The most widely available data on ambient standards concern air quality, particularly for sulfur dioxide
(SO2), total suspended particulate matter (TSP), and nitrogen oxides (NOx). Different countries have different
standards on air quality (2). The US Clean Air Act regulates 189 toxic pollutants and criteria pollutants,
whereas Japan’s Air Pollution Control Law designates only 10 regulated pollutants.
Air pollutants can be classified according to their physical and chemical composition as follows:
Inorganic Gases. Sulfur dioxide, hydrogen sulfide, nitrogen oxides, hydrochloric acid, silicon tetrafluoride,
carbon monoxide, carbon dioxide, ammonia, ozone, and others (14).
Organic Gases. Hydrocarbons, terpenes, mercaptans, formaldehyde, dioxin, fluorocarbons, and others.
Inorganic Particulates. Lime, metal oxides, silica, antimony, zinc radioactive isotopes, and others.
Organic Particulates. Pollen, smuts, fly ash, and others.
CO and CO
Carbon monoxide is a colorless, odorless, poisonous gas produced by incomplete combustion
of fossil fuels. In the detection of carbon monoxide, the most commonly used methods are indicator tubes, iodine
pentoxide, spectrometry, and gas chromatography.
In industrialized countries nitrogen compounds are common pollutants. Nitrogen oxides are pro-
duced when fuel is burned at very high temperatures. Colorless nitric oxide (NO) gas tends to combine further
with O2in the air to form poisonous brown nitrogen dioxide. In the presence of sunlight, NO2absorbs ultravi-
olet radiation to break down into NO and atomic O, which reacts with O2to form ozone (O3). Measurements of
NO can be made by nonautomatic or automatic methods.
Sulfur compounds are among the main contaminants in air pollution. They are produced when
materials containing sulfur as impurity are heated or burned. In industrialized nations, burning of bituminous
coal produces 60%, fuel oil 14%, and metallic ore smelting, steel, and acid plants 22% of the SOxemission.
The other 4% comes from many diverse sources. The main compound, SO2, is a colorless gas with a sharp
choking odor. Some sulfur oxides are formed in air as secondary pollutants by the action of oxygen, ozone, and
nitrogen oxides on hydrogen sulfide (H2S). SO2combines with oxygen to make sulfur trioxide (SO3). When the
atmospheric conditions are ripe, a highly corrosive sulfuric acid mist can form by reaction of SO3and water
Many automatic and nonautomatic devices are manufactured to measure sulfur compounds in the atmo-
sphere. The most frequently used methods are flame photometric detectors, West and Gaeke colorimetric and
p-rosaniline methods, electrolytic methods, hydrogen peroxide methods, and amperimetric methods.
Most hydrocarbons are not poisonous gases at the concentrations found in air; nev-
ertheless, they are pollutants because, when sunlight is present, they combine with nitrogen oxide to form
complex variety of secondary pollutants that are known to be the main causes of smog. Concentrations of
hydrocarbons are determined by many methods: filtration; extraction; and chromatographic, adsorption, and
fluorescence spectrophotometry. Dispersive and nondispersive infrared analyzers are also used to measure low
concentrations of hydrocarbons and other organic compounds, as well as carbon monoxide and carbon dioxide.
Pollutant particulates are carbon particles, ash, oil, grease, asbestos, metals, liquids, and
SiO2dusts, particularly in remote areas. Heavy particles in the atmosphere tend to settle quickly. However,
small particles are the main pollutants, and they are permanently suspended in air as aerosols. Therefore,
collection of settled particles is not necessarily representative of all types of particles in the air. The size of
particulates suspended in air as aerosols may vary from 30 µmto0.01µmorless.
Aerosols exist in individual particles or in condensed agglomerated form as coarse particles. Their stability
in the atmosphere influenced by gravity settling, coagulation, sedimentation, impaction, Brownian movement,
electric charge, and other phenomena. The identification and measurement of particles in air may be made
by a number of methods, such as settling and sedimentation, filtration, impingement methods, electrostatic
precipitation, thermal precipitation, and centrifugal methods.
Measurement of Air Pollution.
Accurate measurements of air pollution are necessary to establish accept-
able levels and to establish control mechanisms against offending sources (2). Accurate prediction of pollution
helps in setting policies and regulations, as well as in observing the effect on humans, plants, vegetation,
animals, environment, and properties. Nevertheless, precise estimation of substances responsible for air pol-
lution is difficult due to geographical, physical, and seasonal variations. Currently many studies are taking
place to understand the processes involving the formation, accumulation, diffusion, dispersion, and decay of
air pollution and the individual pollutants causing it. Effective national and international control programs
depend very much on this understanding.
A fundamental requirement for an air pollution survey is the collection of representative samples of
homogeneous air mixtures. The data must include the content of particulate and gaseous contaminants and
their fluctuations in space and time. Geographical factors—horizontal and vertical distribution of pollutants,
locations of the sources of contaminants, air flow directions and velocities, intensity of sunlight, time of day—and
the half-lives of contaminants must be considered to be able to determine level of pollution in a given location.
The sampling must be done by proven and effective methods and supported by appropriate mathematical and
statistical analysis (14).
Two basic types of sampling methods are used in determining of air pollution: spot sampling (sometimes
termed grab sampling) and continuous sampling. These techniques can be implemented by a variety of instru-
ments. Automatic samplers are based on one or more of methods such as electrolytic conductivity, electrolytic
titrimetry, electrolytic current or potential, colorimetry, turbidimetry, photometry, fluorimetry, infrared or ul-
traviolet absorption, and gas chromatography. Nonautomatic samplers are based on absorption, adsorption,
condensation, or the like.
Causes of Air Pollution.
Gaseous and particulate pollutants are emitted into the atmosphere from a
variety of both natural and man-made sources. Man-made pollutant emissions, predominantly from combustion
sources, have given rise to a range of environmental problems on global, regional, and local scales. Most
important air pollutants can be attributed primarily to five major sources: transportation, industry, power
generation, space heating, and refuse burning (2). Approximately 90% by weight of this pollution is found to
be gaseous, and the remaining 10% is the particulate matter.
Energy Usage. The consumption of energy is governed by the laws of thermodynamics. When energy is
used, it is not lost or destroyed, but simply transformed to some other form of energy. In terms of energy flows,
earth is an open system with energy inputs entering and outputs leaving. Virtually all the flows are driven by
solar energy that enters biophysical systems by being absorbed, stored, and transported from place to place.
Humans gain most of their nonfood energy from burning fossil fuels (10).
An adequate supply of energy is essential for the survival and development of all humans. Yet energy
production and consumption affect the environment in a variety of ways. Consumption patterns in commer-
cially traded energy sources indicate continued growth. The long-term prospects for traditional energy sources
seem adequate despite the warnings put forward in the 1970s. Identified energy reserves have increased, but
renewable energy sources such as firewood continue to be scarce—an increasingly serious issue for people in
developing countries. The percentage worldwide uses of natural energy sources in the 1990s are as follows:
32% oil, 26% coal, 17% gas, 14% biomass, 6% hydro, and 5% nuclear.
More than half of the world population rely on the biomass fuels such as firewood, charcoal, and other
traditional but not commercial fuels for their energy sources. Some 300 million people in Africa alone rely
on biomass for cooking, heating, and lighting. The use of wood fuel for cooking and space heating presents
environmental and social problems because the wood is being used up faster than it is being replaced. Scarcity
of wood fuel is currently thought to affect about 1.5 billion people.
Over the next 100 years, energy demand is likely to increase substantially. But, in general, our knowledge
of future demands for energy, raw materials, food, and environmental amenities is extremely uncertain. There
is also little knowledge about the basic drivers, such as the world’s future population.
Industry. Different industrial plants emit different types of air pollutants. Thermal power plants emit
soot, ash, and SO2; metallurgical plants emit soot, dust, gaseous iron oxide, SO2, and fluorides; cement plants
emit dust; plants of the heavy inorganic chemical industries emit waste gases such as SO2,SiF
NO2; plants emit malodorous waste gases; and so on. These pollutants may be due to incomplete conversion of
products, or due to discharge of secondary components and impurities. In general, industrial plants create the
greatest diversity of pollutants; they emit SO2(33%), particulate matter (26%), HC (16%), CO (11%), NOx(8%),
and others (6%). However, as the nature and technology of industrial operations change in time, the amounts
and proportions of the pollutants change too.
Even in industrialized nations, industry accounts for only about 17% of the total pollution. The other
major contributors are transportation (60%), power generation (15%), space heating (6%), and refuse burning
Transportation. Transport activities affect the environment by the use of land and fuel resources and
by emission of noise and pollutants. Environmental impacts from transportation systems have reached global
dimensions in energy use and CO2emission. Traffic-related CO2emissions are estimated at 1.3 billion tons of
carbon, rivaling the 1.6 billion tons due to land use. At the local level, traffic pollutants in the form of solid
particulates, nitrogen oxides, and sulfur compounds are the principle precursors of acid rain.
In recent years, strict environmental regulations on the level of emissions has reduced the emission per
vehicle; however, growth in the number of vehicles has more than canceled that achievement, and emissions
have increased by about 20% since the 1970s. Also, the ownership of road vehicles is increasing worldwide.
The number of vehicles per 1000 persons varies from one country to another; in the United States it is about
700, in the OECD countries 400, and in India and some African countries 1 or 2. It is estimated that there are
about 550 million vehicles in the world, and this figure is likely to double in the next 30 years. For prevailing
emission trends demand growth must be slowed, technology must improve for zero emission, and alternative
non-emission-based systems must be developed. It is becoming apparent that incremental innovations are not
enough to reverse emission trends and reduce the environmental impacts of transport systems (10).
Other important sources of air pollution are maritime and air traffic, both of which are increasing world-
wide. Over the past 10 years the number aircraft-kilometers flown by scheduled airlines has increased rapidly
in many countries.
Greenhouse Effect. The greenhouse effect is a natural phenomenon due to presence in the atmosphere
of so-called greenhouse gases such as COx,CH
2O (as shown in Table 3), which absorb outgoing
terrestrial radiation while permitting incoming solar radiation to pass through the atmosphere relatively
unhindered. The natural greenhouse effect warms the earth by about 33C. The enhanced greenhouse effect,
brought about by the release of additional gases, results in an average increase in the warming of the earth’s
surface. The consensus in the early 1990s was that the human-induced greenhouse effect had already warmed
the earth by about 0.5C, and a further warming of about 2.0C is expected by 2030 (3). The primary cause
of the human-induced greenhouse effect is burning of fossil fuel for energy, but land use is also a source of
harmful gases (2).
Carbon Dioxide. Carbon dioxide is currently increasing at 0.5% per annum in the atmosphere and now
constitutes approximately 360 parts per million by volume (ppmv), compared to 280 ppmv in preindustrial
times. CO2is increasing by 1.5 ppmv each year, or 4% per decade. In the mid-1990s people put 6.7 to 9.3
gigatons (Gt) of carbon into the atmosphere each year. This is made up of about 5.5 Gt/year from fossil-fuel
burning, and about 1.6 Gt/year from deforestation and land use. CO2has a residence of 50 to 200 years
in the atmosphere.
Methane. Methane (CH4) accounts for 8% to 15% of the total greenhouse effect. The atmospheric concen-
tration of CH4has been rising steadily in the last 300 years. The current concentration of 1.72 ppmv
(the preindustrial level was 0.7 ppmv) corresponds to an atmospheric reservoir of around 4900 million
tons (Mt) of CH4, which is increasing by around 30 Mt CH4per year. The largest emission of green-
house methane gas is completely independent of human intervention and comes from natural wetlands.
However, human action continues to intervene in the natural balance by altering the areas of wetland,
primarily by draining it for agricultural and other uses. The mean atmospheric life cycle of methane is 12
Nitrous Oxide. Atmospheric N2O emissions are currently rising at a rate of 0.8 ppbv per year, so the
concentration is likely to be 320 ppbv within 50 years (the preindustrial level was 275 ppbv). Total
production of nitric oxides is estimated to be about 0.01 Gt/year, approximately 60% coming from natural
emissions from land and sea, 15% from fossil-fuel burning, 10% from biomass burning, and the remainder
from the application of nitrogen fertilizers. The principal sink of N2O is destruction by ultraviolet light in
the stratosphere; it thus has a long atmospheric residence time of approximately 150 years.
Halocarbons. There is a whole family of carbon compounds in the atmosphere, collectively known as halocar-
bons, that contain chlorine, fluorine, iodine, or bromine. Halocarbons, including CHCs and hydrochloroflu-
orocarbons (HCFCs), are among the main causes of ozone-layer destruction and the greenhouse effect.
The preindustrial CFC level was 0; today, the combined CFC and HCFC level is about 370 pptv.
Agricultural and cropland expansion have interfered substantially with global flows of carbon dioxide
and methane, which are the most important greenhouse gases. Agriculture dominates anthropogenic methane
emission. For carbon, the impact of agriculture and land use is secondary to other industrial activities and
energy use. Current biotic carbon emission occurs largely in the tropics, where most biomass burning and land-
use changes are concentrated. Annual biotic carbon emission is estimated to be 1.1 Gt of elemental carbon. It
is estimated that from 1800 to 1990 about 190 Gt of greenhouse gases were released globally into atmosphere
as a result of land-use change, while approximately 200 Gt were released from fossil-fuel consumption in the
same period.
Biodiversity. Biodiversity, or biological diversity, is an umbrella term to describe collectively the variety
and variability of living things. It encompasses three basic levels of organization in living systems: the genetic,
species, and ecosystem levels. Plant and animal species are the most commonly recognized units of biological
diversity. Extinction of many species is caused by human activities through habitat disruption, introducing
diseases and predators, overhunting, and environmental changes such as climatic changes, destruction of
forests, and water and air pollution. The best way to save species is to preserve their natural habitat, and
most countries have taken legal and physical measures to protect endangered species from extinction. Also,
the idea of protecting outstanding scenic and scientific resources, wildlife, and vegetation has taken root in
many countries and developed into national policies, embracing both terrestrial and marine parks.
Biodiversity can be estimated and measured in a variety of ways, but species richness, or species diversity,
is one of the most practical and common measures (15). It is estimated that there are grave threats to many
species; up to 5% to 50% in some genera of animals and plants are threatened with extinction in the foreseeable
future (1). In 1996, the Red List of Threatened Animals issued by the World Conservation Union identifies 5205
species in danger of extinction. It has been estimated by biologists that three species are being eliminated
every hour in tropical forests alone. Much of the decline is caused by habitat destruction, especially logging.
Only 6% of the world’s forests were formally protected, leaving 33.6 million km2vulnerable to exploitation.
Surveys of concentrations of contaminants in organisms and measurements of their biological effects
reflect exposure to contaminants in the organisms’ habitats. The main measured parameters are concentrations
of organochlorin residues and radionuclides. There are many examples of traces of pollutants in organisms.
Some examples are migratory birds (waterfowl), which have been found to have accumulated considerable
amounts of polychlorinated biphenyl (PCB) residues. Similarly, intensive accumulation of DDT, PCB, chlordane,
and toxaphene residues in freshwater fish have been noted. Concentrations of heavy metals such as mercury,
cadmium, and lead in fish muscle and shellfish are reported. There are not many reports of monitoring data
on concentrations of contaminants in plants on regional, national, or global scales. Mosses and lichens have
high capacity for interception and retention of airborne and waterborne contaminants such as lead, sulfur, and
their compounds.
The worldwide diffusion of agricultural crops and animals has been taking place for centuries. The
pervasive diffusion of crops is accompanied by the diffusion of new pests and of species that became nuisances
in new ecosystems where their growth is unchecked by natural predators. Some typical examples of human-
induced shifts in the ecosystem will be dealt with next.
Fish Catch.
Fish is an important source of protein in the human diet, and three-quarters of the world
catch is used directly for human consumption. The increasing adoption of production quotas for managing
fish stocks has contributed to overexploitation of certain fish stocks for the last century, and several fisheries
remain severely depleted. Nevertheless, aquaculture has the potential to supplement fish catches and help
offset the declining stocks of some fish species. It is estimated that aquaculture production may be about 7 Mt
to 8 Mt worldwide; thus this technology helping to preserve the natural environment.
Marine Mammals.
World catches of many species of marine mammals have declined, in part because
populations have been significantly reduced, or because of legal restrictions placed on killing or capture. For
example, in the case of whales, permits have been granted only for scientific purposes. Catches of most whales
have diminished very substantially, and there is continual pressure to stop whaling altogether.
Protected Areas and Wildlife.
Conserving the diversity of wildlife and plant genetic stocks is essential
to maintain the potential for the development of new and improved varieties, which may benefit both man and
environment. The protection of wildlife resources has developed at both the species and the ecosystem level.
Both developing and developed countries around the world have perceived certain natural areas to be
worth preserving and therefore have designated thousands of protected areas. There are five categories of
protected areas: strict nature reserves; national parks and their equivalent; natural monuments; managed
nature reserves and wildlife sanctuaries; and protected landscapes and seascapes.
Although significant advances in the establishment and management of protected areas have been made
over the last few decades, networks are not complete, and management suffers from a range of significant
problems, particularly in the Tropics. There are many actions that can be recommended for improvement of
the coverage and management of the protected area systems.
There are organizations in place that prohibit commercial international trade in currently endangered
species and closely monitor trade in species that may become endangered. Trade is prohibited for about 600
endangered species and regulated for about 30,000 species, which are not yet in jeopardy of extinction, but
soon may be. Trade restrictions and prohibitions have been credited with rescuing several species, such as
American alligators, from the brink of extinction; but other species adversely affected by trade, such as the
African elephant and the rhinoceros, continue to suffer disastrous population declines, largely brought about
by illegal poaching and trade.
Some populations of endangered animals have been making a comeback, such as the fur seal, the short-
tail albatross, and the whooping crane. Others have remained stable or fluctuated slightly. In some species
or subspecies there have been marked or even drastic declines. Examples are the black and northern white
rhinoceroses, the Tana River red colobus, the Riddle turtle, the Atilan grebe, the Californian condor, and the
pink pigeon.
Noise and Electromagnetic Pollution.
Noise is often defined as unwanted sound. Usually it is unwanted because it is either too loud for
comfort or is an annoying mixture that distracts us. Thus, the notion of noise is partly subjective and depends
on one’s state of mind and hearing sensitivity.
Noise is the most ubiquitous of all environmental pollutants. Excessive noise can affect humans physi-
ologically, psychologically, and pathologically in the forms of loss of hearing, disturbed sleep, stress, anxiety,
headaches, emotional trauma, nausea, and high blood pressure.
Loudness increases with intensity, which is measured on a decibel (dB) scale, illustrated in Table 4. Daily
noises in a busy building or city street average 50 dB to 60 dB; in a quiet room, about 30 dB to 40 dB. Hearing
damage begins around 70 dB for long exposure to sound such as a loud vacuum cleaner. At about 130 dB,
irreversible hearing loss can occur almost instantaneously.
In terms of population exposure, transportation is the major source of environmental noise. Recent esti-
mates from OECD countries show that approximately 15% of the population is exposed to road traffic noise.
About 1% of the population is exposed to aircraft noise in excess of 65 dB, which is the proposed guideline
for maximum daytime exposure to noise for populations living near main roadways. Despite advance in noise
reduction technology and the adoption of environmental quantity standards in a number of countries, exposure
to noise appears to an increasing problem, particularly in urban areas.
Electromagnetic Pollution.
Another important environmental pollution is likely to be electromagnetic
pollution, at low frequencies in the vicinity of power lines and at high frequencies in mobile communication
systems and near transmitters. The flow of electricity through the wires produces an electromagnetic field that
extends through air, vacuum, and some materials. Concerns over the health effects of such fields, in particular
cancer, have been growing since the late 1960s. Numerous studies have yielded conflicting results, so the
question is controversial.
Fig. 8. Man-induced increases in greenhouse gases cause the temperature to rise, which in turn puts more moisture in
the atmosphere. This leads to a cause-and-effect cycle.
Climate Change. It is generally accepted that increases in atmospheric concentrations of greenhouse
gases, such as carbon dioxide, methane, nitrous oxide, CFCs, and ozone, lead to increases in surface temperature
and global climatic change, as shown in Fig. 8. Calculations using climate models predict that increases of CO2
and other greenhouse gases will result in an increase in the global mean equilibrium surface temperature in
the range of 1.5to 5.5C. If present trends continue, the combined concentration increases of atmospheric
greenhouse gases will be equivalent to doubling of the CO2concentration, possibly by as early as the year 2030.
Models are currently unable to predict regional-scale changes in climate with any degree of certainty, but there
are indications that warming will be enhanced at high latitudes and summer dryness is likely to become more
frequent in midcontinental, midlatitude regions of the northern hemisphere. Increases in global sea levels are
also forecast; it is estimated that a warming of 1.5to 5.5C can produce a seal-evel rise of between 20 cm and
165 cm (3).
A variety of data sources are available for analysis of long-term trends in climate variables such as surface
and upper air temperatures, precipitation, cloud cover, sea ice extent, snow cover, and sea level (4, 7, 10).
Indicators of Climatic Change.
For comparison with the results of model calculations, large-scale av-
erage changes in climatic indicators in regional, hemispheric, and global trends are needed. Changes in the
surface air temperature give the most direct and reliable predicted effect of greenhouse-gas-induced climatic
changes. Global land-based surface temperature data sets have been compiled since 1927 by various authorities
(e.g., the Smithsonian Institution). Data analysis indicate that since the turn of the twentieth century global
temperatures have increased by 0.3to 0.7C. Using data collected over land and sea, publications indicate that
greater warming occurred over land areas in the southern hemisphere and that some regions in the northern
hemisphere showed signs of cooling.
Large-scale trends of air temperature change in the troposphere and the stratosphere have also been
assessed. A warming trend of 0.09C per decade is indicated at the 95% confidence level in the tropospheric
(850 mb to 300 mb) layer. A cooling of 0.62C per decade is indicated in the stratospheric (100 mb to 50 mb)
Precipitation has high spatial and temporal variability. However, analysis of historical and current data
indicates an increase in the higher latitudes (35to 70N) over the last 40 to 50 years, but a decrease in the
lower latitudes.
Cloud cover plays an important, but complex role in determining the earth’s radiation budget and cli-
mate. Clouds reflect incoming short-wave radiation from the sun back in the space, but also absorb thermal
long-wave radiation emitted by the earth. The net effect of clouds depends on the cloud type, height, and
structure. Results obtained from the analysis of cloud coverage indicate that average total cloud coverage has
increased over the last 90 years in the United States.
Fluctuations of glaciers and sea levels are sensitive indicators of climatic change. Information on the
glaciers consists of the location, surface area, width, orientation, elevation, and morphological characteristics
of individual ice masses. Recent studies indicate that the mass of glaciers in wet maritime environments has
tended to increase, whereas the mass of glaciers in dry, continental areas is decreasing.
Sea levels also appear to be changing, by about 1.0 cm/yr. This figure is arrived at from the historical
data obtained from tide-gauge measurements and current data obtained from devices such as Late Holocene
sea-level indicators.
Ozone Depletion. People have had a number of impacts on the atmosphere, ranging from the local to
the regional and global scales. Arguably, the most important impacts on the global atmosphere are the enhanced
greenhouse effect and the depletion of the ozone layer, both of which have the potential to affect many other
aspects of the Earth’s physical, chemical, and biological systems. Particularly in recent years, research and
development on the measurement of ozone depletion has attracted considerable attention due to its implications
for the earth’s temperature and for human health (10). World ozone levels have been monitored continuously
by NASA, and information is updated daily on its Web site. The ozone level on the day of submission of this
article is given in Fig. 9 (16). The accurate measurement of ozone and the ozone layer is important; therefore,
in this article some detailed treatment of the measurements methods will be given.
Ozone (O3) is naturally occurring gas concentrated in the stratosphere at about 10 km to 50 km above the
earth’s surface. It is formed in a reaction of molecular oxygen (O2) caused by ultraviolet radiation of wavelengths
less than 0.19 µm, in which the oxygen is split in the presence of catalysts and recombines to produce ozone.
Ozone plays a major role in absorbing virtually all UV radiation entering the atmosphere from the sun. Ozone
is destroyed in the atmosphere in three ways: it reacts with UV radiation at wavelengths of 0.23 µmto0.29
µm to produce oxygen molecules; it reacts with nitric oxide (NO); and it reacts with atomic chlorine (Cl). The
natural ozone cycle has been interfered with by the release of chemicals such as CFCs. CFCs do not break
down in the lower atmosphere, but gradually diffuse into the stratosphere, where strong UV breaks then down
to their monomers, releasing atomic chlorine. Initially, the chlorine reacts with ozone in a photolytic reaction
to produce chlorine monoxide (ClO) and oxygen:
The ClO then reacts with atomic oxygen to produce atomic chlorine and oxygen:
These two reactions act as a catalytic cycle leading to a chain reaction, which effectively removes two
molecules of ozone in each cycle, thus causing large-scale ozone destruction in the ozone layer.
Depletion of the ozone layer was first noticed in Antarctica, but is not restricted to that area. It is estimated
that there has been about 14% reduction in the ozone levels of the world. Depletion of the ozone layer affects
both the energy cycle in the upper atmosphere and the amount of UV radiation reaching the earth’s surface.
Many devices are available for ozone measurements. There are six main methods to determine the ozone
in air: electrolytic titrimetry, coulometric titrimetry, reaction with nitric oxide, ultraviolet spectrometry, and
ultraviolet photometry. For stratospheric ozone determinations ultraviolet methods are mainly used.
Fig. 9. Ozone levels round the globe are monitored by satellites, and the information is updated daily by NASA (16).
Global warming, soil contamination, ozone depletion, hazardous wastes, acid rain, radioactive hazards, cli-
mate change, desertification, deforestation, noise, and diminishing biodiversity are illustrations of current
environmental problems that are common to nations worldwide. The growth in human population and rising
or deteriorating living standards due to use or misuse of technology are intensifying these problems. If the
existing human–environment interaction continues and if the human population increases with the current
trends, the evidence shows that irreversible environmental damage may be inflicted on this fragile planet.
However, the knowledge gained by science and clever use of technology, coupled with the willingness and pos-
itive attitude of people as individuals and as nations, can navigate a sustainable path to save the world from
possible man-created disasters. Although not sufficient, there is evidence of understanding of the fragility of
the environment by individuals and nations. There are also positive signs of development in the international
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Curtin University of Technology
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... With the increase in equipment and "things", there is also a growing concern about the environmental risks that they can cause from the production process to disposal. Among the problems generated by technological means are: pollution; chemical composition of materials; consumption of renewable resources or not; generation of waste resulting from the disposal of obsolete electronics; disturbance in ecology and health hazards [Cubitt 2016, Eren 2002]. ...
... With the increase in equipment and "things", there is also a growing concern about the environmental risks that they can cause from the production process to disposal. Among the problems generated by technological means are: pollution; chemical composition of materials; consumption of renewable resources or not; generation of waste resulting from the disposal of obsolete electronics; disturbance in ecology and health hazards [Cubitt 2016, Eren 2002]. ...
Conference Paper
Full-text available
Internet of Musical Things (IoMusT) is one of several subfields of the Internet of Things (IoT) and it relates to several areas of study, such as ubiquitous and mobile music, human-computer interaction, new interfaces for musical expression and participatory art. This paper makes a bibliographic review on the general definitions of this field, explaining what Musical Things are, classifying them according to their behavior and communication role, in addition to discussing their applications in Ubimus. Among the contributions to IoMusT research, the authors also discuss the social, economic and environmental challenges faced in this area.
This book presents the insight for evaluating analytical data obtained from environmental samples. Often, analyses performed on a few samples can lead to misplaced concern on the wrong analytes. For example, a geologist would know which trace metals might be naturally present in the source rock underlying a site, but not know which metals should be expected because of tire wear or which polynuclear aromatic hydrocarbons would be present because of a nearby powerplant. This book provides you with references to support decision making regarding selection of contaminants. This text was written to provide guidance for those evaluating analytical data obtained from environmental characterization and restoration projects. The purpose of the book is to ensure that informed decisions are made regarding compounds that occur naturally or from nonpoint sources such as atmospheric deposition and surface-water runoff.
Sumario: Introduction and overview (Land use and global environmental change: a social science perspective) -- The land use causes of global warming (Assessing greenhouse gas fluxes from the terrestrial biota. The role of tropical forests in the carbon cycle. Soils, bogs and wetlands: greenhouse gas fluxes) -- Policy analysis (An investigation of the causes of tropical deforestation. Agricultural policy to reduce methane emissions. Forestry options for offsetting emissions. The international policy dimension. Land use options for greenhouse gas abatement: prospects and constraints) Bibliografía: P. 239-259
Libro de ecología, manual general por temas que incluye la solución de la problemática referenciada. Es un compendio de las ciencias ambientales en internet y pretende darnos un panorama de esta materia desarrollada fundamentalmente por problemas globales como el calentamiento terrestre, la pérdida de la capa de ozono, la energía nuclear y la contaminación del agua entre otros. Aborda las políticas mundiales enfocadas en la producción económica mundial y el desarrollo sustentable como prerequisito de nuestra supervivencia.
  • P Singleton
  • D Castle
Singleton P. Castle D. Short Environmental Assessment, London: Thomas Telford, 1999.
Global Environmental Change: Research Pathways for the Next Decade
NRC, Global Environmental Change: Research Pathways for the Next Decade, Committee on Global Change Research, Board on Sustainable Development, Policy Division, National Research Council, Washington: National Academy Press, 1999.
Air Pollution in the 21st Century-Priority Issues and Polcy
  • T Schneider
T. Schneider Air Pollution in the 21st Century-Priority Issues and Polcy, Studies in Environmental Science, Amsterdam: Elsevier, 1998.
Global Environmental Crises-An Australian Perspective
  • G Aplin
G. Aplin, et al. Global Environmental Crises-An Australian Perspective, Melbourne, Australia: Oxford University Press, 1999.