Society and the environment
J.J. Blackford
GY3068, 2790068
2011
Undergraduate study in
Economics, Management,
Finance and the Social Sciences
This is an extract from a subject guide for an undergraduate course offered as part of the
University of London International Programmes in Economics, Management, Finance and
the Social Sciences. Materials for these programmes are developed by academics at the
London School of Economics and Political Science (LSE).
For more information, see: www.londoninternational.ac.uk
This guide was prepared for the University of London International Programmes by:
Dr J.J. Blackford, University of Manchester
This is one of a series of subject guides published by the University. We regret that due to
pressure of work the author is unable to enter into any correspondence relating to, or arising
from, the guide. If you have any comments on this subject guide, favourable or unfavourable,
please use the form at the back of this guide.
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Published by: University of London
© University of London 2007
Reprinted with minor revisions 2011
The University of London asserts copyright over all material in this subject guide except where
otherwise indicated. All rights reserved. No part of this work may be reproduced in any form,
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Contents
Contents
Chapter 1: Introduction........................................................................................... 1
Aims ............................................................................................................................. 1
Learning outcomes......................................................................................................... 1
Why study society and the environment?........................................................................ 1
This subject guide........................................................................................................... 2
Syllabus.......................................................................................................................... 2
Reading advice............................................................................................................... 3
Essential reading............................................................................................................ 3
General and introductory reading.................................................................................... 4
Further reading............................................................................................................... 4
Online study resources.................................................................................................... 8
Examination advice........................................................................................................ 9
Chapter 2: Environmental systems and society..................................................... 11
Essential reading.......................................................................................................... 11
Further reading............................................................................................................. 11
Learning outcomes....................................................................................................... 12
Definitions and key concepts......................................................................................... 12
Environmental cycles.................................................................................................... 13
Society and society–environment interactions................................................................ 14
Natural variability of the environment........................................................................... 15
The nature of human impacts....................................................................................... 16
Changing perceptions of the environment..................................................................... 19
Environmental sociology............................................................................................... 24
Political ecology and social ecology............................................................................... 25
A reminder of your learning outcomes........................................................................... 26
Sample examination questions...................................................................................... 26
Chapter 3: Environmental pollution...................................................................... 29
Essential reading.......................................................................................................... 29
Further reading............................................................................................................. 29
Learning outcomes....................................................................................................... 29
Introduction and definitions.......................................................................................... 30
Pollution of the atmosphere.......................................................................................... 31
Water pollution............................................................................................................ 34
Soil pollution................................................................................................................ 36
Acid deposition and acid rain........................................................................................ 38
A reminder of your learning outcomes........................................................................... 39
Sample examination questions...................................................................................... 39
Chapter 4: Environmental hazards........................................................................ 45
Essential reading.......................................................................................................... 45
Further reading............................................................................................................. 45
Learning outcomes....................................................................................................... 45
Introduction................................................................................................................. 45
Risk transference.......................................................................................................... 48
Earthquakes................................................................................................................. 48
Volcanic hazards........................................................................................................... 50
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68 Society and the environment
Hurricanes.................................................................................................................... 51
Poverty, risk and vulnerability ....................................................................................... 53
A reminder of your learning outcomes........................................................................... 53
Sample examination question....................................................................................... 54
Chapter 5: Global environmental change: atmospheric changes.......................... 57
Essential reading.......................................................................................................... 57
Further reading............................................................................................................. 57
Learning outcomes....................................................................................................... 58
Introduction................................................................................................................. 58
Global warming ........................................................................................................... 58
The human impact on climate: greenhouse gases.......................................................... 60
Future climates and mitigation strategies...................................................................... 60
Stratospheric ozone depletion....................................................................................... 61
A reminder of your learning outcomes........................................................................... 63
Sample examination questions...................................................................................... 63
Chapter 6: Global environmental change: terrestrial changes............................. 65
Essential reading.......................................................................................................... 65
Further reading............................................................................................................. 65
Learning outcomes....................................................................................................... 65
Desertification.............................................................................................................. 66
Soil erosion.................................................................................................................. 67
Deforestation............................................................................................................... 69
A reminder of your learning outcomes........................................................................... 70
Sample examination questions...................................................................................... 71
Chapter 7: Causes of, and solutions to, environmental problems......................... 73
Essential reading.......................................................................................................... 73
Further reading............................................................................................................. 73
Learning outcomes....................................................................................................... 74
Introduction................................................................................................................. 74
Causes of environmental problems............................................................................... 74
Solutions to environmental problems............................................................................ 77
A reminder of your learning outcomes........................................................................... 81
Sample examination questions...................................................................................... 81
Appendix: Sample examination paper.................................................................. 83
ii
Chapter 1: Introduction
Chapter 1: Introduction
Aims
This course introduces you to the key issues faced by society which
affect the natural environment. Your studies will focus on the
nature, consequences, causes of, and possible solutions to the major
environmental problems faced by society. The subject will require some
understanding of natural environmental processes.
Learning outcomes
By the end of the course and associated reading, you should know and
understand:
• the operation of selected components of environmental systems
• the causes and nature of human impacts on the environment
• the implications of key environmental issues for human societies
• the range of possible solutions to environmental problems, and be able
to evaluate these.
You will develop the following abilities and skills:
• collation and critical evaluation of information on a range of
environmental issues from a range of sources
• judging the evidence in support of theories and explanations
• developing a reasoned, well-structured argument in written form.
Why study society and the environment?
Environmental issues arise from a growing awareness of problems
caused by the interaction of society (at all spatial scales) and the natural
world. They are increasingly important to policymakers, many types of
businesses, health managers and food producers. Environmental concerns
now influence, and in some cases cause, international agreements and
laws, national environmental regulations and local government actions.
Some environmental issues are considered to be the most important
international issues to face the UN and world leaders. In June 1992,
the United Nations Conference on Environment and Development
(UNCED), sometimes known as the ‘Rio Summit’, agreed declarations
and conventions that included biodiversity, climate change, forests,
oceans and toxins, linked to an Earth Charter – a statement on world
development strategies and sustainability (see Chapter 8; UNCED 1993;
Kemp,1 1994; 2004; Beder, 2006). A follow-up to UNCED (Rio +5) was
held in 1997 in New York, and reviewed progress following UNCED,
concluding that few targets had been met. A further agreement, specific
to climate change, was made in Kyoto in 1998, although not agreed
by several key countries. In 2002, a further conference (Earth Summit
+10, the World Summit on Sustainable Development) was organised in
Johannesburg (see Kemp, 2004; www.earthsummit2002.org/) and again
the conclusions were mixed, with few measurable targets being met and
difficult decisions and targets avoided (for a critical view see the Böll
foundation view at www.worldsummit2002.org/). Debates around the
policy implementation following the summits continue. Some countries
The official publication
of the UNCED
conference includes
the whole range of
agreements: United
Nations Conference
on Environment
and Development,
Earth Summit 1992.
(London: Regency
Press Corporation for
UNCED, 1993) [ISBN
0952046911].
1
1
68 Society and the environment
have not kept to the agreements signed, but the effort involved and high
profile of the environmental issues discussed are a sign of the importance
of the interaction between society and the environment.
Whatever degree or diploma programme you are following, therefore,
consideration of environmental issues is important. In addition, studying
the environmental issues facing the world can change your perspective,
and possibly your way of life. Hopefully, it will be an enjoyable and
rewarding study.
This subject guide
The aim of this guide is to direct you in studying for the 68 Society and
the environment course. Many of the main points are included and
examples given, but it does not attempt to cover in detail all elements
of the material relevant to each subject area. Additional reading is
essential throughout, and it is through this reading that you will learn and
understand the broad range of information that you will be examined on.
You should read each chapter in this guide first, and then the listed texts.
The subject guide is intended to show you what the important points and
issues are and how to organise your notes from additional reading.
In every chapter you will come across sections, called ‘activities’. These
are short exercises to let you test your progress and to help you to reflect
on what you have just read. You will be able to make most progress if you
attempt each of these activities as you come across them in the text. You
should refer to the reading and write your answers down or discuss them
with your fellow students.
I include a list of ‘learning outcomes’ for each chapter. Learning outcomes
tell you what you should have learned from that chapter of the subject
guide and the relevant reading. You should pay close attention to the
learning outcomes and use them to check that you have fully understood
the topic(s).
Example examination questions are included, some of which are given as
worked examples. You should attempt some of these questions as part of
your preparation for the examination.
We recommend that if you are studying this course over the equivalent of
one academic year, you need to spend a minimum of six to seven hours per
week studying.
Syllabus
Environmental systems and society: Analysis of the varied two-way
interactions between human societies and natural environmental systems.
Changing perceptions of environment. Population growth, technology
change, energy use and environmental impacts. The role of market
defects in creating resource scarcity and environmental problems. The
Gaia hypothesis. Ecocentric and technocentric attitudes. Environmental
ethics. Nature as a social construct. ‘Wilderness’ concepts. Concept of
environmental sociology.
Environmental pollution: The nature, causes and consequences
of environmental pollution. The main types of pollution by medium –
biosphere, hydrosphere and atmosphere, including a consideration of
pesticides, sewage, nitrates and phosphates, urban smog, marine pollution,
nitrogen and sulphur emissions and acidification; transboundary pollution.
2
Chapter 1: Introduction
Environmental hazards: The nature, significance and trends of
natural hazard impacts, such as earthquakes, hurricanes and floods. Risk
and vulnerability. The variety of strategies that can be adopted to minimise
hazards; poverty and disasters; risk transference.
Global environmental change: Global environmental change,
including the enhanced ‘greenhouse effect’, stratospheric ozone depletion,
desertification, soil resource depletion, fuelwood shortages and the
depletion of tropical and other natural forests.
Causes of and solutions to environmental concerns: The
underlying causes of environmental problems, and the proposed solutions.
The assessment methods used to evaluate environmental damage
caused by development, and the benefits of control and conservation
(environmental impact assessment and benefit–cost analysis). Economic
instruments in environmental regulation (emissions trading, green
taxation). International agreements. Conclusions.
Reading advice
The study of both the environment and society are potentially huge
undertakings, both areas are infinitely complex and broad, and both could
be a lifetime’s work. Ideally, it would be beneficial to fully understand
what the environment is and how it operates, and to have background
knowledge of social form and function before addressing the interaction
between the two. However, for a subject that forms part of a broader
degree or diploma programme, some key definitions will be a sufficient
introduction. The opening sections of Chapter 2 are intended as a guide
to reaching a suitable starting point.
The content of this subject is quite varied, including physical properties of
the Earth, aspects of economics and social science and at times involving
the principles of chemistry. At present, no single textbook covers all of this
ground adequately. If your access to library resources is limited, therefore,
you may be advised to select from the topics and subtopics included here
when you are preparing for the examination – remember that you have a
choice of questions to answer.
Essential reading
There are three books which between them cover almost all aspects
of the subject with sufficient depth and, along with this subject guide,
should prepare you for the examination. These are listed below and are
recommended for purchase. The text by Kemp (2004) is the closest to a
single volume that covers the syllabus. This is aimed at people who are new
to the subject, rather than advanced learners, however, and you will need to
supplement it with more specialist reading as outlined for each chapter. For
a more detailed guide to some of the scientific principles, including aspects
of environmental chemistry and physics, see Jackson and Jackson (2000).
Pickering and Owen (1997), although now a decade old, still provides a
broad coverage and good discussions of many of the issues involved.
Kemp, D.D. Exploring environmental issues: an integrated approach. (London:
Routledge, 2004) [ISBN 9780415268646].
Jackson, R.W. and J.M. Jackson Environmental science: the natural environment
and human impact. (Harlow: Longman, 2000) [ISBN 9780582414457].
Pickering, K.T. and L.A. Owen An Introduction to Global Environmental Issues.
(London: Routledge, 1997) second edition [ISBN 9780415140986 or
paperback 9780415102285].
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68 Society and the environment
General and introductory reading
In addition to these books, there are a number of comprehensive,
introductory-level environmental science texts available that cover much
of the material relevant to this paper, although each has its limitations.
Images of ‘Third-world’ countries and their problems are sometimes
generalised, and few give a balanced view between environmentalist and
other viewpoints. Some are very US- or UK-based, in terms of examples,
discussion of policies and social attitudes. However, the texts listed below
are suitable as an introduction, although not as highly recommended for
this particular subject as those above. For more information on the cycles
and physical mechanisms of the natural environment see Park (2001). If
you are also studying 147 Physical geography, the recommended texts
for that subject will also be useful for elements of this one, particularly in
order to understand the natural systems of soil, water, living organisms
and the atmosphere.
Bush, M.B. Ecology of a changing planet. (New Jersey: Prentice Hall, 1997)
[ISBN 01303729621].
Chiras, D.D. Environmental science. (Sudbury: Jones and Bartlett, 2006)
seventh edition [ISBN 0763708607].
Miller, G.T. Living in the environment: principles, connections and solutions.
(Belmont: London: Brooks/Cole 2006) fourteenth edition. See also other
editions [ISBN 9780534997281].
Nebel, B.J. and R.T. Wright Environmental science. (New Jersey: Prentice Hall,
1998) sixth edition [ISBN 013835331X].
Park, C.C. The environment: principles and applications. (London: Routledge,
2001) [ISBN 9780415217712].
Reference books
Two dictionaries, with explanations of technical terms and concepts have
recently been published. Either one of these will be useful for this subject,
especially if you have not studied related material before.
Kemp, D.D. The environment dictionary. (London: Routledge, 1998)
[ISBN 041512733X].
McGraw-Hill. McGraw-Hill dictionary of environmental science. (New York:
McGraw-Hill Publishing, 2003) [ISBN 0071421777].
Further reading
In addition to the general environmental science texts, there are specialist
volumes dealing with subsections of the subject. Full lists of alternative
and additional reading are included for each chapter. These lists are long!
However, you are not expected to read all of every book. Long lists have
been included in the hope that you will find that some of the books are
immediately available and also so that the subject matter that particularly
interests you will be covered in depth by one or more of the listed texts.
You will need to support your learning by reading as widely as possible
and by thinking about how these principles apply in the real world. To
help you read extensively, you have free access to the virtual learning
environment (VLE) and University of London Online Library (see below).
4
We have compiled a list here of all the Further reading in the guide
for ease of reference. Those listed below with ** are the most highly
recommended of the more specialised books, covering subsections in
greater depth than the three essential textbooks listed above. The most
highly recommended texts in each chapter list are marked with an asterisk
(*). If more than one of the listed texts is marked, these are intended
either as alternatives or to cover different subsections within the chapter.
Chapter 1: Introduction
Adams, W.M. Green development: environment and sustainability in the Third
World. (London: Routledge, 1990) [ISBN 0415080509].
Alexander, D. Natural disasters. (London: UCL Press, 1993)
[ISBN 1857280938].
Alloway, B. and D.C. Ayers Chemical principles of environmental pollution.
(Glasgow: Blackie Academic and Professional, 1993) [ISBN 0751400130].
Attfield, R. Environmental ethics. (Cambridge: Polity, 2003)
[ISBN 0745627374].
Barry, R.G., T. Chase and R.J. Chorley Atmosphere, weather and climate.
(London: Routledge, 2003) eighth edition [ISBN 9780415271714].
Beder, S. Environmental principles and policies: an interdisciplinary introduction.
(London: Earthscan, 2006) [ISBN 9781844074044].**
Bell, M. and M.J.C. Walker Late Quaternary environmental change: physical and
human perspectives. (Harlow: Prentice Hall, 2005) second edition [ISBN
9780130333445].
Blaikie, P., L. Davis, T. Cannon and B. Wisner At risk: natural hazards, people’s
vulnerability and disasters. (London: Routledge, 2003) second edition [ISBN
9780415252164].*
Bolt, B.A. Earthquakes. (New York: W.H. Freeman, 2003) fifth edition
[ISBN 9780716756187].
Boserup, E. Population and technology. (Oxford: Blackwell, 1981)
[ISBN 0631128174].
Bowers, J. Sustainability and environmental economics. (Harlow: Addison
Wesley Longman, 1997) [ISBN 058227656X].
Bradley, R.S. and P.D. Jones Climate since AD 1500. (London: Routledge, 1995)
[ISBN 0415120306].
Briggs, D.J. and F.M. Courtney Agriculture and environment. (Harlow: Longman,
1989) [ISBN 0582300002].
Brown, L.R., C. Flavin and H. Kane Vital signs. (London: Earthscan, 1998)
[ISBN 1853835439].
Bruce, J.P., H. Lee and E.F. Haites (IPCC) Climate change 1995: economic and
social dimensions of climate change. (Cambridge: Cambridge University
Press, 1996) [ISBN X231134311].
Bryant, E. Natural hazards. (Cambridge: Cambridge University Press, 2005)
second edition [ISBN 9780521537438].
Bush, M.B. Ecology of a changing planet. (Harlow: Prentice Hall, 1997) [ISBN
01303729621].
Chester, D. Volcanoes and society. (London: Edward Arnold, 1993)
[ISBN 0340517611].
Clark, R.B. Marine Pollution. (Oxford: Clarendon Press, 1997) third edition
[ISBN 019850070X].
Cooke, R.U and J.C. Doornkamp Geomorphology in environmental management:
a new introduction. (Oxford: Clarendon Press, 1990) second edition [ISBN
0198741502].
Cunningham, W.P. and B.W. Saigo Environmental science: a global concern.
(Dubuque, IA: Wm. C. Brown Publishers, 1997) fourth edition
[ISBN 0697286711].
Cutter, S. Living with risk – the geography of technological hazards. (London:
Edward Arnold, 1993) [ISBN 0340529873].
Dunlap, R.E. (ed.) Sociological theory and the environment: classical foundations,
contemporary insights. (Lanham: Rowman & Littlefield, 2002) [ISBN
0742501868].
Ekins, P. A new world order: grassroots movements for global change. (London:
Routledge, 1992) [ISBN 0415071143].
Elsom, D.M. Atmospheric pollution: a global problem. (Oxford: Blackwell, 1992)
[ISBN 0631173080].**
Elsom, D.M. Smog alert: managing urban air quality. (London: Earthscan, 1996)
[ISBN 1853831921].
5
68 Society and the environment
Etkin, D. ‘Risk transference and related trends: driving forces towards more
mega-disasters’ in Global environmental change: Part B: Environmental
hazards, Volume 1. (Oxford: Elsevier, 1999).
Farmer, A. Managing environmental pollution. (London: Routledge, 1997) [ISBN
0415145155].
Francis, P. and C. Oppenheimer Volcanoes. (Oxford: Oxford University Press,
2003) [ISBN 9780199254699].
Gilpin, A. Environmental economics: a critical overview. (Chichester: Wiley,
2000) [ISBN 0471985597].
Glacken, C.J. Traces on the Rhodian shore: nature and culture in Western thought
from ancient times to the end of the eighteenth century. (Berkeley: University
of California Press, 1973) [ISBN 0520023676].
Goudie, A. and H. Viles The earth transformed: an introduction
to the human impact on the environment. (Oxford: Blackwell, 1997)
[ISBN 0631194649].**
Goudie, A. The human impact on the natural environment. (Oxford: Blackwell,
2005) [ISBN 9781405127042].**
Harrison, R.M. Pollution: causes, effects and control. (Cambridge: Royal Society
of Chemistry, 2001) fourth edition [ISBN 08540446216].**
Harrison, R.M. (ed.) An introduction to pollution science. (Cambridge: Royal
Society of Chemistry, 2005) [ISBN 0854048294].
Harvey, L.D.D. Global warming: the hard science. (Harlow: Pearson, 1999)
[ISBN 0582381673].
Hester, R.E. and R.M. Harrison Air quality management. (London: Royal Society
of Chemistry, 1997) [ISBN 0854042350].
Hill, M.K. Understanding environmental pollution. (Cambridge: Cambridge
University Press, 2004) second edition [ISBN 0521527260].**
Houghton, J. Global warming: the complete briefing. (Cambridge: Cambridge
University Press, 2004) third edition [ISBN 0521528747].**
IPCC. Climate change 2001: impacts, adaptation and vulnerability. (Cambridge:
Cambridge University Press, 2001) [ISBN 0521807689].*
IPCC. Climate change 2001: the scientific basis. (Cambridge: Cambridge
University Press, 2001) [ISBN 0521014956].*
Irwin, A. Sociology and the environment. (Cambridge: Polity, 2001)
[ISBN 0745613608].*
Jepma, C.J. Tropical deforestation: a socio-economic approach. (London:
Earthscan, 1995) [ISBN 1853832383].
Johnston, R.J. Environmental problems: nature, economy and state. (London:
Belhaven Press, 1989) [ISBN 1852930004].
Kemp, D.D. Global environmental issues: a climatological approach. (London:
Routledge, 1994) second edition [ISBN 041510310X].
Lamb, H.H. Climate, history and the modern world. (London: Methuen, 1995)
second edition [ISBN 0415127343].
Light, A. and H. Rolston Environmental ethics: an anthology. (Oxford: Blackwell,
2002) [ISBN 0631222944].
Lomborg, B. The skeptical environmentalist: measuring the real state of the world.
(Cambridge: Cambridge University Press, 2001)
[ISBN 0521804477].*
Lovelock, J.E. Gaia: a new look at life on earth. (Oxford: Oxford University
Press, 1979) [ISBN 019217665X].
Mannion, A. Agriculture and environmental change: temporal and spatial
dimensions. (Chichester: Wiley, 1995) [ISBN 0471954780].
Mannion, A.M. Global environmental change: a natural and cultural
environmental history. (Harlow: Longman Scientific & Technical, 1998)
second edition [ISBN 0582277221].
Markham, A. A brief history of pollution. (London: Earthscan, 1996)
[ISBN 1853832138].
6
Chapter 1: Introduction
Mason, C.F. Biology of freshwater pollution. (Harlow: Longman, 2002)
fourth edition [ISBN 0130906395].
Mather, A.S. and K. Chapman Environmental resources. (Harlow: Longman,
1995) [ISBN 0582101689].
Meadows, D.H. et al. The limits to growth: a report for the club of Rome’s project
on the predicament of mankind. (London: Pan, 1974) [ISBN 0330241699].
Meadows, D.H., D.L. Meadows and J. Randers Beyond the limits: global collapse
or a sustainable future? (London: Earthscan, 1992) [ISBN 1853831301].
Middleton, N.J. and D.S.G. Thomas (eds) World atlas of desertification. (London:
UNEP/Edward Arnold, 1997) second edition [ISBN 9780340555125]
Miller, G.T. Living in the environment: principles, connections and solutions.
(Belmont: London: Brooks/Cole, 2006) fourteenth edition
[ISBN 9780534997281].
Morgan, R.P.C. Soil erosion and conservation. (Harlow: Longman, 1995)
[ISBN 0582244927].
Myers, N. Rainforests. (Emmaus, PA: Rodale Press, 1993) [ISBN 0875965970].
Nath, B. and H.D. Devuyst Sustainable development. (Brussels: Vubpress, 1996)
[ISBN 9054871156].
O’Riordan, T. ‘The challenge for environmentalism’ in Thrift, N. and R. Peet,
(eds) New models in geography. (London: Unwin Hyman, 1989)
[ISBN 0044454201].
O’Riordan, T. Environmental science for environmental managers. (Harlow:
Longman, 1995) [ISBN 0582218896].
Park, C.C. The environment: principles and applications. (London: Routledge,
2001) [ISBN 9780415217712].
Parry, M.L. and T. Carter Climate impact and adaptation assessment. (London:
Earthscan, 1998) [ISBN 1853832669].
Pearce, D.W., A. Markandya and E.B. Barbier Blueprint for a green economy.
(London: Earthscan, 1989) [ISBN 18538306606].
Pearce, D.W. and K. Turner Economics of natural resources and the environment.
(New York: Harvester Wheatsheaf, 1990) [ISBN 0745002250].
Pearce, D.W. Economic values and the natural world. (London: Earthscan, 1993)
[ISBN 0262161389].
Pepper, D. Eco-socialism: from deep ecology to social justice. (London: Routledge,
1993) [ISBN 0415097185].
Perman, R., Y. Ma and J. McGilvray Natural resources and environmental
economics. (Harlow: Addison Wesley Longman, 1996) [ISBN 0582257271].
Redclift, M. and G. Woodgate International handbook of environmental sociology.
(London: Edward Elgar, 1997) [ISBN 1840642432].
Rees, J. Natural resources, allocation, economics and policy. (London: Routledge,
1990) second edition [ISBN 0415051037].
Roberts, N. The Holocene: an environmental history. (Oxford: Blackwell, 1998)
second edition [ISBN 0631186379].
Schumacher, E.F. Small is beautiful: a study of economics as if people mattered.
(London: Blond and Briggs, 1973) [ISBN 085634012X].
Simmons, I.G. Changing the face of the earth. Culture, environment, history.
(Oxford: Blackwell, 1996) second edition [ISBN 0631199241].
Simon, J.L. and H. Kahn The resourceful earth: a response to Global 2000.
(Oxford: Blackwell, 1984) [ISBN 0631134670].
Slaymaker, O. Geomorphic hazards. (New York: Wiley, 1996)
[ISBN 0471962139].
Smith, K. Environmental hazards: assessing risk and reducing disaster. (London:
Routledge, 2004) fourth edition [ISBN 0415318041].**
Ward, R. and K. Smith Floods. (London: Wiley-Liss, 1998) [ISBN 0471952486].
Weber, E. Assessment methodology and modelling. Volume 2. (New York: Plenum,
1982)
7
68 Society and the environment
Journals
To help you read extensively, all students have free access to the University
of London online library where you will find the full text or an abstract of
some of the journal articles listed in this guide. You will need a username
and password to access this resource. Details can be found in your Student
handbook or online at: www.external.ull.ac.uk/index.asp?id+lse
As the syllabus covers a range of subject areas and is interdisciplinary in
nature, there are no all-encompassing journals that can be recommended.
However, New Scientist and Scientific American regularly cover
environmental topics and provide up-to-date information about pollution,
global change and other aspects of resource use. Specialist journals that
contain relevant material include:
• Climatic Change
• Disasters
• Environmental Pollution
• Ambio: Journal of Environmental Management
• Nature
• Science
• Water, Air and Soil Pollution.
Relevant review papers also appear in Progress in Human Geography and
Progress in Physical Geography.
Online study resources
In addition to the subject guide and the Essential reading, it is crucial that
you take advantage of the study resources that are available online for this
course, including the virtual learning environment (VLE) and the Online
Library.
You can access the VLE, the Online Library and your University of London
email account via the Student Portal at:
http://my.londoninternational.ac.uk
You should receive your login details in your study pack. If you have not,
or you have forgotten your login details, please email
uolia.support@london.ac.uk quoting your student number.
The VLE
The VLE, which complements this subject guide, has been designed to
enhance your learning experience, providing additional support and a
sense of community. It forms an important part of your study experience
with the University of London and you should access it regularly.
The VLE provides a range of resources for EMFSS courses:
• Self-testing activities: Doing these allows you to test your own
understanding of subject material.
• Electronic study materials: The printed materials that you receive from
the University of London are available to download, including updated
reading lists and references.
• Past examination papers and Examiners’ commentaries: These provide
advice on how each examination question might best be answered.
• A student discussion forum: This is an open space for you to discuss
interests and experiences, seek support from your peers, work
collaboratively to solve problems and discuss subject material.
8
Chapter 1: Introduction
• Videos: There are recorded academic introductions to the subject,
interviews and debates and, for some courses, audio-visual tutorials
and conclusions.
• Recorded lectures: For some courses, where appropriate, the sessions
from previous years’ Study Weekends have been recorded and made
available.
• Study skills: Expert advice on preparing for examinations and
developing your digital literacy skills.
• Feedback forms.
Some of these resources are available for certain courses only, but we
are expanding our provision all the time and you should check the VLE
regularly for updates.
Making use of the Online Library
The Online Library contains a huge array of journal articles and other
resources to help you read widely and extensively.
To access the majority of resources via the Online Library you will either
need to use your University of London Student Portal login details, or you
will be required to register and use an Athens login:
http://tinyurl.com/ollathens
The easiest way to locate relevant content and journal articles in the
Online Library is to use the Summon search engine.
If you are having trouble finding an article listed in a reading list, try
removing any punctuation from the title, such as single quotation marks,
question marks and colons.
For further advice, please see the online help pages:
www.external.shl.lon.ac.uk/summon/about.php
Internet
Internet sites are increasingly being used to provide information and
in teaching. If you have access to the internet, it is possible to use this
resource to gain recent and relevant material for this course, including
websites supporting the textbooks listed and some journal papers. There
are websites maintained by environmental organisations and pressure
groups,2 and by news information services such as the BBC. A small
number are included in the reference lists in the following chapters, but be
cautious about web-based material. While some web-based information is
of a high standard,3 there is no overall quality control. Many news-based
sites sensationalise environmental issues without going into the subjects in
depth. Some are one person’s personal viewpoint. While most books and
journal papers are edited, checked and reviewed by experts in the field,
web pages can be produced by anyone, and say anything, with no checks
or controls. Do not rely on all websites to provide objective, balanced
material.
See, for example, the
Greenpeace homepage at
www.greenpeace.org/
2
For example, the climatic
change pages of NOAA at
www.noaa.gov/climate.html
3
Examination advice
Important: the information and advice given here are based on the
examination structure used at the time this guide was written. Please
note that subject guides may be used for several years. Because of this
we strongly advise you to always check both the current Regulations for
relevant information about the examination, and the VLE where you
should be advised of any forthcoming changes. You should also carefully
9
68 Society and the environment
check the rubric/instructions on the paper you actually sit and follow
those instructions.
Remember, it is important to check the VLE for:
• up-to-date information on examination and assessment arrangements
for this course
• where available, past examination papers and Examiners’ commentaries
for the course which give advice on how each question might best be
answered.
The commentaries and examination papers, which you should use as part
of your preparation for exams, are found on the International Programmes
website at:
www.londoninternational.ac.uk/current_students/programme_resources/
lse/exams.shtml
The examination currently requires you to answer any four out of 12
questions in three hours. The range of questions will cover a broad
selection of the topics in the syllabus, as shown in this subject guide.
However, there is no guarantee that every section will be covered. When
answering examination questions in this field, remember to answer the
question directly and specifically, rather than writing generally about
the subject area. Also, use examples wherever possible to back up the
points made. Including diagrams can make a point more effectively, and
sometimes more quickly, than can a written explanation.
Example questions, including some worked examples, are included in this
subject guide at the end of each chapter.
10
Chapter 2: Environmental systems and society
Chapter 2: Environmental systems and
society
Essential reading
Jackson, R.W. and J.M. Jackson Environmental science: the natural environment
and human impact. Chapters 5 and 9.
Kemp, D.D. Exploring environmental issues: an integrated approach. Chapter 1.
Pickering, K.T. and L.A. Owen An introduction to global environmental issues.
Further reading
Attfield, R. Environmental ethics. (Cambridge: Polity, 2003)
[ISBN 0745627374].
Bell, M. and M.J.C. Walker Late Quaternary environmental change: physical and
human perspectives. (Harlow: Prentice Hall, 2005) second edition
[ISBN 9780130333445].
Boserup, E. Population and technology. (Oxford: Blackwell, 1981)
[ISBN 0631128174].
Briggs, D.J. and F.M. Courtney Agriculture and environment. (Harlow: Longman,
1989) [ISBN 0582300002].
Bush, M.B. Ecology of a changing planet. (New Jersey: Prentice Hall, 1997)
[ISBN 01303729621].
Chiras, D.D. Environmental science. (Sudbury: Jones and Bartlett, 2006)
seventh edition [ISBN 0763708607].
Dunlap, R.E. (ed.) Sociological theory and the environment: classical foundations,
contemporary insights. (Lanham: Rowman & Littlefield, 2002)
[ISBN 0742501868].
Ekins, P. A new world order: grassroots movements for global change. (London:
Routledge, 1992) [ISBN 0415071143].
Glacken, C.J. Traces on the Rhodian shore: nature and culture in Western thought
from ancient times to the end of the eighteenth century. (Berkeley: University
of California Press, 1973) [ISBN 0520023676].
Goudie, A. and H. Viles The earth transformed: an introduction to the human
impact on the environment. (Oxford: Blackwell, 1997) [ISBN 0631194649].
*Goudie, A. The human impact on the natural environment. (Oxford: Blackwell,
2005) [ISBN 9781405127042].
*Irwin, A. Sociology and the environment. (Cambridge: Polity, 2001)
[ISBN 0745613608].
Light, A. and H. Rolston Environmental ethics: an anthology. (Oxford: Blackwell,
2002) [ISBN 0631222944].
*Lomborg, B. The skeptical environmentalist: measuring the real state of the world.
(Cambridge: Cambridge University Press, 2001) [ISBN 0521804477].
Lovelock, J.E. Gaia: a new look at life on earth. (Oxford: Oxford University
Press, 1979) [ISBN 019217665X].
Mannion, A.M. Global environmental change. (Harlow: Longman, 1998) second
edition [ISBN 0582277221]. See also previous (1991) edition.
Meadows, D.H. et al. The limits to growth: a report for the club of Rome’s project
on the predicament of mankind. (London: Pan, 1974) [ISBN 0330241699].
Meadows, D.H., D.L. Meadows and J. Randers Beyond the limits: global collapse
or a sustainable future? (London: Earthscan, 1992) [ISBN 1853831301].
Miller, G.T. Living in the environment: principles, connections and solutions.
(Belmont: Wadsworth Publishing Co., 2006) fourteenth edition
[ISBN 9780534997281].
11
68 Society and the environment
O’Riordan, T. ‘The challenge for environmentalism’ in Thrift, N. and R. Peet,
(eds) New models in geography. (London: Unwin Hyman, 1989)
[ISBN 0044454201].
O’Riordan, T. Environmental science for environmental managers. (Harlow:
Longman, 1995) [ISBN 0582218896].
Pepper, D. Eco-socialism: from deep ecology to social justice. (London: Routledge,
1993) [ISBN 0415097185].
Redclift, M. and G. Woodgate International handbook of environmental
sociology. (London: Edward Elgar, 1997) [ISBN 1840642432].
Roberts, N. The Holocene: an environmental history. (Oxford: Blackwell, 1998)
second edition [ISBN 0631186379].
Schumacher, E.F. Small is beautiful: a study of economics as if people mattered.
(London: Blond and Briggs, 1973) [ISBN 085634012X].
Simmons, I.G. Changing the face of the earth. Culture, environment, history.
(Oxford: Blackwell, 1996) second edition [ISBN 0631199241].
Simon, J.L. and H. Kahn The resourceful earth. A response to Global 2000.
(New York: Blackwell, 1984) [ISBN 0631134670].
(*) indicates the most highly recommended texts.
Learning outcomes
By the end of this chapter and the relevant reading, you should be
able to:
• describe the relationships between people and the environment,
through the processes of agricultural and industrial development
• outline and quantify the major global environmental cycles
• discuss changes in environmental perception, and explain different
types of ‘environmentalism’
• outline the role of environmental sociology and related sub-disciplines
in understanding environment–society interaction.
Definitions and key concepts
What is actually meant by the Environment? One possible definition is
provided by Jackson and Jackson (2000):
The environment may be conceptualised as being composed of a number
of interconnected processes and phenomena. These include the formation
of rocks, the climate system, the cycling of biologically important elements
and the interactions between organisms and their surroundings.
This broad approach serves well to understand the interaction by humans
on natural systems, and demonstrates the overall interconnectedness of
the components of the global natural environment: oceans, freshwater,
atmosphere, soils, solid earth and organisms. When society, in this case
defined simply as ‘people and their actions’, impact upon natural systems,
this can be perceived as a problem in one of three ways:
• Impact on human health and well-being: where the impact of society
has caused a change in natural conditions to the point at which human
life or health is at risk, this is considered an environmental problem.
• Human impact on natural systems: where human action has caused a
loss of habitat, destruction of species or individual organisms, or other
disruption of the natural systems, for example by pollution, this is also
considered an environmental problem.
12
Chapter 2: Environmental systems and society
• Human impact on landscape: this is considered a problem mostly in
the more developed countries of the world (MDCs1), where remaining
‘unspoiled’ areas are valued as places to visit and for recreation.
With these principles in mind, it is useful to reach an understanding of the
natural systems being referred to. Natural systems are usually described in
term of ecosystems – the interaction between different plants and animals
and their habitats. Ecosystems can be quantified by way of mass, energy or
numbers of individuals, and provide a useful basic unit of understanding
the natural living world. Examples of ecosystems are provided by Jackson
and Jackson (2000) and Bush (1997).
More Developed
Countries, also defined
as MEDCs (More
Economically Developed
Countries), contrasting
with Less Developed
Countries (LDCs).
1
Environmental cycles
A way of understanding the global environment, also applicable at a local
scale, is to look at the cycles of key elements in the earth, biosphere and
atmosphere. Global cycles of carbon, nitrogen, sulphur and water illustrate
the concept, but others are important, particularly oxygen, phosphorus,
sodium and other common elements.
The carbon cycle is shown below, and can be used as an example to
construct the others. Cycle models are quantified either in terms of
percentages, actual global quantities (mass or volume) or in terms of
flux measurements (rates of transfer of an element from one place or
state to another). In most cases, quantities are only estimates as precise
calculation is very difficult, which adds to the uncertainty surrounding
human involvement. Most elements that are considered to act in a cycle
do so in different forms and different states. For example, carbon in the
atmosphere is mostly in the form of the gas carbon dioxide (CO2), but
exists also as methane (CH4) and carbon monoxide (CO). In water, it can
be in the form of carbonate (CO3) or bicarbonate (HCO3), or as soluble
organic material, including dissolved organic carbon (DOC). Water is
present in the atmosphere as a vapour, as a liquid in ocean and freshwater
environments, and also as ice. Figure 2.1 shows the global carbon cycle as
a quantified system of stores and fluxes. For each store, inputs of carbon
are called sources and outputs are sinks. Carbon is one of the most studied
biogeochemical cycles and yet even this is only an estimated cycle model.
Measurement uncertainties exist in many parts of the system, as with all
global cycles.
When learning material for this course, a useful start would be to study
the major cycles and their main components (stores and fluxes). A way of
examining human impacts on the global system is to quantify the effects in
a system model.
13
68 Society and the environment
atmosphere: total 60.249
key:
15
x 10
mol C
0.14
C02
59.9
15
x 10 mol C a-1
8.30
0.083
C0
0.019
8.3 x 10
8.32
C04
0.33
-3
0.083
oceans: total 3197.45
soluble organic
material
83.2
10.39
9.99
3.3 x 10 -3
0.0125
HC03-/CO3 2-
biomass
0.25
3114
0.233
0.05 (rivers)
0.05
crust: total 2.83 x 10 6
sediments:
inorganic 2.16 x 10 6
organic 6.7 x 105
coal
oil
gas
fossil fuels:
291
19.1
11.6
live
dead
biomass:
Figure 2.1: The global carbon cycle (after Jackson and Jackson, 2000: 108). Figures
are in x1015 mol. Carbon, and fluxes (transfers) in x1015 mol per year.
Society and society–environment interactions
Societies change through time and differ between regions, to such an
extent that any study of societal–environmental interaction must be
placed in a definite time frame and located spatially. In Europe, humans
‘progressed’ from hunter-gatherers, entirely dependent on naturally
occurring food sources, through agricultural subsistence, to a technological
and industrial society, over the course of around 10,000 years. This
transition has been usefully simplified by Roberts (1998).
Roberts suggests that humans were initially ‘part of’ their environment,
and hence dependent upon it. This changed with the growth and spread of
agriculture, to a state where people controlled their environment to some
extent, but were still dependent upon elements of the natural world. The
third stage is one where people to a large extent manipulate their own
environment and although interaction still exists, there is more impact of
society on the environment than the other way around. This progression
is not always valid, however, as in some places industrialised societies
and subsistence agriculture, and even hunter-gatherer communities, exist
within the same region.
14
46.6
99.9
Chapter 2: Environmental systems and society
time
H E
H
H
E
E
HUNTING/FISHING
GATHERING
AGROECOSYSTEMS
URBANINDUSTRIAL
LARGELY NATURAL
ENVIRONMENTS
CULTURAL
LANDSCAPE
‘BUILT
ENVIRONMENT’
DIRECT DEPENDENCY
ON ENVIRONMENT
MODIFICATIONS OF
ENVIRONMENT
MAJOR HUMAN
IMPACT
H
E
H
E
H
E
Figure 2.2: Changing relationships between society and the environment through
time. H = Humans, E = Environment (after Roberts, 1998: 246). Circles show the
nature of the interaction, and the letters linked by arrows show the relative
impact of one over the other.
Natural variability of the environment
Natural systems, including the cycles discussed above and every known
ecosystem, are dynamic. This means that they change continually, and this
change can range from long- to short-term. The climate system provides a
useful example.
Between approximately two million years ago and the present day, there
have been upwards of 22 cyclic switches between ‘glacial’ conditions
and ‘interglacial’ conditions (see Bell and Walker, 2005). In high altitude
and high latitude areas, ice sheets and glaciers expand greatly during
the glacial times, and areas that are now temperate are subjected to
permafrost and tundra conditions. Elsewhere, low-latitude arid regions
become wetter, because the atmospheric circulation patterns that
determine rainfall distribution are altered. These cold periods end,
however, usually rapidly, and are replaced by the warmer climatic system
similar to that seen now (interglacials). This process of global warming
is clearly independent of human impact, as humans were absent or very
scarce for most of these large-scale climatic events. In the last 2,000 years,
natural climatic changes have been shown by historical records and by the
earliest temperature recordings (meteorological records). These changes
have included the ‘Medieval Warm Period’ (approximately AD 900–1300)
and the Little Ice Age (AD 1600–1850) (See Bell and Walker, 2005;
Pickering and Owen, 1997). On short-term timescales, climatic variability
is a fact of everyday life, for example the changes between night and day,
or winter and summer. Even then summers are not always the same, and
every day is different to the last. Ecosystems are equally dynamic.2
See Jackson and
Jackson (2000).
2
15
68 Society and the environment
Figure 2.3: Biomass changes in an area of European farmland over the last 15,000
years, showing the ‘dynamic equilibrium’ concept. Periods of instability, and changes
between states, have been caused by natural and by human factors. After Roberts
(1998: 246).
Natural variability in Earth’s systems is highly significant in the context of
this subject for a number of reasons:
• It makes the precise study of human impact difficult (see for example,
Chapter 5 on predicting future climates).
• It shows that the idea of a ‘natural balance’ that can be upset by society
can be misleading, and that changes can occur naturally.
• It shows that prediction of future trends is extremely difficult.
One interpretation of environmental changes over time is the model of
‘metastable equilibrium’ (Roberts, 1998). This model accepts and includes
natural variability but suggests that human action causes the system to
change to a different state. Figure 2.3, above, shows how biomass has
changed over 15,000 years at a theoretical site in NW Europe.
The aim of this section was to set the scene for the material that follows,
and to introduce some basic ideas. However, there would be some benefit
in rereading this section, and your notes from the reading, when you have
covered the rest of the syllabus.
The nature of human impacts
By a combination of technical innovation and global colonisation, people
have caused massive changes to the natural world. Two main functions of
human society cause these changes:
• food production and
• industrial activities.
People use things to better their lives. They have done this from the
beginning of the species, indeed in some definitions the use of tools
defines the beginnings of Homo sapiens. As they use things, primarily the
Earth’s resources, people inevitably alter the world around them.
Food production
First, people have to eat. They can eat other animals or plants, either
collected from the wild or produced specifically. Each mode of obtaining
16
Chapter 2: Environmental systems and society
food causes alteration to the physical environment. Almost every society
now produces food by using systems of agriculture. While initial farming
communities had to feed populations of tens of thousands, the world
population is now six billion, most of whom are not actively engaged
in food production. The environmental impact of this food production
is huge, and historically increasing over the last 6,000 years. Food
production affects every global biogeochemical cycle, regional cycles and
systems (for example catchment-scale hydrology) and local-scale ecology.
Industrial activities
Secondly, people produce more and more complex tools to improve their
lives. These range from water carriers and cooking facilities, to complex
products such as yachts and computers. Almost every society now has
an industrial component, and takes part in what has become a global,
integrated and highly complex, environmentally-impacting production and
distribution system. The following sections provide an outline of how food
production and industry impact on the environment.
Agricultural environmental impacts
The types and consequences of agriculture, both past and at present, are
regionally distinct. However, four main aspects of agricultural processes
can be identified which have environmental consequences that are
generally applicable.
Deforestation
The benefits of clearance are that it makes more agricultural land
available and produces useful timber. Also, there is less risk to livestock
and humans from predators. When fire is used as a means of clearing
trees, a temporary release of soil nutrients on combustion improves
growth of crops or grass. Human mobility and visibility is enhanced. The
environmental consequences, however, include loss of numbers of some
species of plants and animals, and risk of extinctions. A reduction in
natural habitat size and continuity is also caused, as is a long-term loss of
soil fertility due to reduced organic accumulation on the surface. Altered
drainage characteristics (less evapotranspiration and faster run-off) are
also caused, and the near-ground atmosphere becomes less humid. Surface
wind velocity increases, and soil temperatures become more variable.
Cultivation
Cultivation of the soil, or tillage, is practised in almost all arable
(crop-growing) systems. The benefits include increased soil aeration,
and enhanced root and shoot penetration. There is a reduced risk of
waterlogging, and an often beneficial increase in surface temperature.
Organic material is mixed into the deeper soil, and weeds are better
controlled. The problems include an increased risk of soil erosion, loss of
soil organisms, increased soil water throughput, therefore increased rates
of leaching (the loss of nutrients to water flowing down through the soil)
and illuviation (movement of soil components down the profile, where
they reaccumulate). In dry areas, there is an increased risk of salinisation
and calcification (where salts accumulate at the surface of the soil,
reducing soil fertility). All of these problems can lead to long-term loss in
soil productivity, even to the point of land abandonment, and permanent
change in the natural plants and animals in an area.3
3
Simmons (1996).
17
68 Society and the environment
Livestock
Livestock farming increases the concentrations of protein and energy in
consumed food. Bi-products such as milk, blood, bone, and skins are also
produced. Food can be stored in a live and mobile form. Problems include
soil compaction, although soil fertility can be increased by reapplication
of animal dung. Reduced plant diversity usually accompanies livestock
agriculture due to the effects of grazing, and reduced animal diversity is
common due to the elimination of predators and herbivores that would
otherwise compete with the domesticated herds.
Arable crops
Arable farming is the most effective way of producing protein and energy
from most land types. A change to arable crops therefore brings increased
food production in a versatile form. In addition, there may be bi-products
such as straw and fibre. Storage of crop surplus allows the over-wintering
of livestock – essential in many societies for winter survival. A significant
environmental impact is reduced (natural) biodiversity, due to the
elimination of weeds and pests. Reduction in insect numbers and diversity
for example, has secondary impacts on the birds or small mammals that
depend on them. In continuously cropped, monoculture4 systems, a
long-term reduction of soil nutrients can be a problem, along with reduced
soil organic matter, as can erosion due to the associated cultivation.5
Industrial systems
The beginnings of industry are varied and dispersed in time and space.
The Bronze Age people, the first metal users, are arguably the first
industrialists, but kilns for pottery manufacture, which used wood and
charcoal as fuels, are known from the early Neolithic period. Mining of
stone is also known from the Neolithic. Coal was used by the Romans and
in China by 2,000 years ago, and oil was extracted in Burma before 1,000
BP.6
4
Single cultivated crop.
Briggs and Courtney
(1989); Goudie and Viles
(1997).
5
6
Simmons (1996).
7
See Simmons (1996).
However, the impact of what we now consider industrialisation, in
particular fossil fuel use and the manufacture of artificial chemicals,
became increasingly common between 300 BP and 100 BP, with power
being derived from coal and then oil and oil products. The use of fossil
fuels became much more common and intensive after around AD 1850.
Associated with industrialisation in most cases has been urbanisation,
the concentration of people and buildings in and around the industrial
areas. In regions where industrialisation is relatively recent, urbanisation
of the population is still going on.
Generalising about the impact of the development of industrial systems
is difficult. Each industrial process is different, and the environment in
which a process takes place may be more, or less, resistant to any impacts.
However, when viewed as ‘intervention in natural systems’, the following
generalisations can be made.7
Raw material extraction
The first stage in an industrial process is the extraction of raw materials.
This can lead to the following environmental consequences:
• land surface disturbance
• loss of habitat
• loss of numbers of some species, with possible extinctions
• air pollution, both local and global, including dust
18
Chapter 2: Environmental systems and society
• water use and intervention in hydrological systems (for example
through the use of dams, diversions, groundwater re-routing),
including water pollution
• soil and sediment contamination.
Extraction processes usually produce waste, and so waste disposal and
land degradation through leaching are further impacts. The concentration
of human settlement, often in previously sparsely populated areas, leads
to transport impacts, human waste, and associated impacts of food and
timber requirements.
Industrial processing
The second major phase is that of industrial processing – the production
of goods or refined raw materials. This leads to energy use with
associated pollution effects, water use and contamination, intervention in
hydrological systems (including water loss to the atmosphere as steam),
groundwater use, river diversion and regulation. Processes can also lead
to contamination of soils, fresh water and seas, thermal pollution and air
pollution.8
8
See Chapter 3.
Other consequences are waste and bi-product disposal problems.
In addition, the concentration of settlement around factory sites
(urbanisation) leads to transport impacts, human waste and further
associated impacts of food, fuel and timber requirements.
Use and disposal
Once the goods have been produced, their use and disposal cause a further
set of impacts. For example, the use of natural resources in packaging,
energy use in transport and disposal, pollution caused by the use of some
products and waste disposal at end of product life, including landfill, sea
dumping and combustion, all of which lead to pollution effects of different
types and scales.
Activity
Find examples of industrial products, materials and processes, and the history of their use
with related environmental impacts. This includes the use of coal (see Chapter 3), oil, and
other primary products and the history of the development and spread of industrialisation
and urbanisation themselves. This background knowledge will help inform your answers to
questions in later sections. Simmons (1996) is a particularly useful source of this information.
Changing perceptions of the environment
As human use of the environment has changed, and the impact of humans
on environmental systems has increased, so have attitudes towards, and
perceptions of what the environment is and how it behaves. Such changes
in attitude are dealt with by Pepper (1993), and in a classic book by
Glacken (1973). The aim of this section is to briefly outline the changes
in attitude, and then review current environmental thinking. Analysis of
the perception of environmental problems may at times seem esoteric, or
irrelevant, but it is arguably an important aspect of understanding why
environmental problems arise, and how solutions may be found.
Population growth and technology change
One of the most important aspects of human interaction with the
environment is in the production and consumption of food. Thomas
Malthus, an English clergyman, famously pointed out that population
19
68 Society and the environment
increases at a faster rate than food production. Populations, he
noted, grow ‘geometrically’ (exponential growth), and food output
‘arithmetically’ (linear growth), leading inevitably to famine, wars
and disease. Rarely has an essay9 been so often quoted as his 1798
publication, and those who currently believe that population growth will
lead inevitably to disaster, or believe that it already has, are known as
neomalthusians.
Malthus, T. (1798). See
Kemp (2004), p. 131.
9
Environmentalism
One response to environmental problems has been for people, individually
and collectively, to protest and campaign against the continued
environmental degradation linked to industrial development. The
responses have been categorised as ‘Environmentalism’, and represent a
broad range of ideas from those who believe in the Earth as a spiritual
being to those who believe that an economic and/or technological solution
is preferable in all cases.
This section covers the possible solutions to environmental problems in
terms of the ideas of ‘ecocentric’ and ‘technocentric’ responses, following
the work of T. O’Riordan (e.g. O’Riordan 1989). The historical roots
of the two viewpoints need to be understood, as well as the possible
reconciliation of the opposing camps, perhaps through ‘green capitalism’
or ‘green consumerism’. The dominant paradigm is currently one of
environmental management, whereby environmental problems are
monitored and managed to reduce impacts.
The way in which human societies perceive their environment is
important because it affects how they use and change that environment.
As technology and lifestyles have changed, so have human perceptions
of environment. There are great variations worldwide because of
cultural, religious, educational and, of course, environmental differences.
The subject has been discussed from a European and North American
perspective by Pepper (1993) and Glacken (1973). In European cultures,
many aspects of which were exported around the world during the
imperialist period, the impact of Christianity on environmental perceptions
is strong. Imperialist attitudes, in terms of humans having dominion
over the natural world, and ideas of stewardship can all be linked to
biblical references and Judeo–Christian philosophies. More scientific
approaches in the seventeenth and eighteenth centuries were also
presented in these terms.10 O’Riordan (1981) traced the current divisions
of (European) environmental attitudes to the Romantic cultural
movement of nineteenth-century Europe.11
Doomsday scenarios
During the late 1960s and early 1970s a number of publications indicated
that the global situation was reaching disaster, in terms of population
growth, resource scarcity, food production, pollution and economic
prospects. The most notable of these was a report prepared for a group
of industrialists (The Club of Rome) by Meadows et al. (1974), The
limits to growth. The limits to growth team used computer simulations of
economic and environmental variables to suggest what would happen
under different conditions. Their results showed an inevitable collapse
of economic output and human population levels following continued
exponential population growth, but a stabilised world model if growth
rates were reduced to zero over a short time-scale. The limits to growth
model had widespread impact, and received much criticism as being
alarmist and inaccurate. Other literature at the time included The
20
10
See Pepper (1993).
See also White, L.
‘The historical roots of
our ecological crisis.’
Science (1967), Vol. 155,
pp.1203–1207 .
11
Chapter 2: Environmental systems and society
Population Bomb, Blueprint for Survival and later (1980) Global 2000
Report to the President.12 All of these analyses assumed that population
growth would soon exceed available resources – a similar argument to that
proposed by Thomas Malthus. Counterarguments were put by Simon and
Kahn (1984) who argued that many indicators showed improvement, and
not an exponential rush towards disaster.
Many of the predictions of the original Limits to growth model have
already been shown to be overly pessimistic. However, population growth
and pollution levels have grown and continue to do so, and the growth
rate of food production has begun to lag behind. In 1992, Meadows et al.
reworked some of their original models, updated the rates and numbers,
and again concluded that economic growth had to be limited in order
to prevent a crash. The key variables, they concluded, were industrial
output and population growth rates – stabilisation of these was required
to maintain standards of living in terms of food and consumer goods. The
debate between zero-growth and wealth creation is discussed in two guest
essays in Miller (1996; 2006) by P. Simon and N. Myers.13
In the tradition of Simon and Kahn, Lomborg (2001) has questioned many
of the environmental movement’s methods and data, arguing instead that
many aspects of the world’s environment are improving, and that global
warming, for example, is not proven, and may be a distraction from more
important social and environmental needs such as food and clean water.
Pepper (1993); Kemp
(2004); Miller (2006).
12
See also Chapter 7,
and The Third World
subject guide (G12).
13
The Gaia hypothesis
The Gaia hypothesis was proposed by James Lovelock in 1979. Lovelock
suggested that the biosphere, that is the atmosphere, living organisms,
water, soils and sediments, can be considered as an organism, with
the capacity to maintain its equilibrium over long timescales through
interactions and feedbacks of environmental cycles. Life on Earth depends
on a certain set of environmental conditions, and these conditions are
in part determined by life itself. This feedback and balancing system is
known as homeostasis, and is compared to the human body which
regulates its own temperature and form. The Gaia hypothesis was justified
by evidence from long-term atmosphere and temperature records, and by
a model known as daisy world. The idea met with controversy, partly
because of ambiguity as to whether the suggestion was that Earth was a
living organism, or acted in a way that resembled one. Lovelock’s own
explanation was that it was like a tree, mostly dead, but supporting life
at the fringes. Although much of the scientific community was sceptical
at the time, the idea was adopted by environmentalist and conservation
groups of many types, and the idea of Gaianism, a position where the
Earth is seen as an organism that can be killed, or one that can adjust itself
to remove humans, persists. The view of the Earth’s systems as global and
interactive now seems common sense, and the only way to understand
global issues such as climatic change.14
14
See Miller (2006).
Ecocentric and technocentric attitudes
Ecocentric and technocentric attitudes represent two alternative
viewpoints of environmental concerns, and lead to alternative strategies
for coping with environmental problems. The terms come from work by
O’Riordan (1981, 1989). The groups can be further subdivided to include
the full range of opinions about environment–society interaction. The
outlines below have been compiled and adapted from O’Riordan (1981)
and (1989).
21
68 Society and the environment
Ecocentric viewpoints
Ecocentrics believe in the intrinsic importance of nature for humanity and
that ecological laws apply to people. Ecocentrics tend to have a lack of faith
in modern, large-scale technology and its associated demands, and are
likely to mistrust the operators of high-technology and central authority.
They also often believe in ‘biorights’, that the natural world can exist for
its own sake, even if there is no direct or indirect benefit to humans.
In addition, the following points are true of ecocentric viewpoints:
• belief that economic growth can be geared to providing for the basic
needs of those below subsistence levels
• anti-materialism
• importance of community affairs and minority (human) rights
• belief in participation, and communal improvement
• integration of work and leisure
• small-scale political and economic structures
• appropriate technology, soft-technology
• self-sufficiency, renewable resource use.
Ecocentric attitudes include the extremes of radical, activist
environmentalists, deep ecologists and Gaianism, and the ideas of
communalism – decentralised economic and political structures, typified
by the work of Fritz Schumacher. You need to know the basis of
Schumacher’s ideas, based on arguments for small-scale systems and
community self-sufficiency.
The deep ecology idea of Norwegian ecologist Arne Naess, a spiritual
and semi-religious attitude to the Earth, and ecofeminist ideologies
are also important.15 The 1980s and 1990s saw the growth of so-called
grass-roots movements as ways of changing environmental policy. These
involve communal action, civil disobedience and media campaigns as ways
of bringing about change, usually the prevention of destruction of a valued
environmental asset. Further information can be found at the website of
the Foundation for Deep Ecology (www.deepecology.org).
Technocentric viewpoints
Technocentric views are centred around a belief in high-technology and
large-scale industry and in the scientists and managers that control the
technology. Technocentrics will also tend to have faith in regulatory
authorities and government agencies. This group of attitudes includes
support of economic growth and accumulation, assuming that suitable
economic adjustments are made to taxes and prices, and suitable
environmentally protective legislation is enforced. There is a general belief
that technological solutions can be found to environmental problems.
In addition, the following points are true of technocentric viewpoints:
• market forces will determine the most cost-effective environmental
outcome
• acceptance of new appraisal or management techniques
• a belief in scientific research
• optimism regarding environmental issues
• suspicion of participation and trust in élite, and in experts
• only institutional laws apply, ecological ones can be/have been
overcome.
22
Miller (2006); Kemp
(2004); Pepper (1993).
15
Chapter 2: Environmental systems and society
Technocentric viewpoints, or ‘human-centred worldviews’16 include
accommodation (after O’Riordan, 1989) and interventionism.
You need to understand the difference between these two, and how the
concept of environmental management, the dominant approach to
environmental concerns worldwide, is seen to fit into the technocentric
spectrum of opinion (see example question below).
16
See Miller (2006).
Both ecocentric and technocentric attitudes can be seen as being responses
to environmental concerns, that is they acknowledge the existence of
problems and suggest solutions.
Wilderness concepts
The idea of wilderness and its conservation and preservation originated
in the late nineteenth century as a response to the expansion of farmland,
deforestation and urban growth at that time in North America and Europe.
While the term wilderness is used most in North America, the idea of
refuges or National Parks, including areas where humans are restricted or
even not allowed at all, is international. There are ‘global’ wildernesses –
most notably Antarctica, and local or regional areas where human impact
up to this point has been low, now designated and as areas with special
protection. In many cases, wilderness areas are contested – especially
between those who want or need to exploit the natural resources or
open up tourist businesses, and those who see the unspoiled areas as of
vital importance to people’s wellbeing. An example of the latter is the
Wilderness Society, whose members aim to ‘deliver to future generations
an unspoilt legacy of wild places’ (www.wilderness.org).
The points of conflict are often logging rights, mining activity and road
building (Kemp, 2004; Miller, 2006; Chiras, 2006). The wilderness idea is
often justified on the basis of providing a precious experience for visitors,
but visitors have to be restricted to preserve the wilderness. Luckily from
the viewpoint of those seeking to protect wilderness area, many are of low
economic potential, inaccessible and inhospitable, especially deserts and
high mountains. Designated areas in Costa Rica and Brazil are forest areas
that without protection are highly likely to be exploited (Chiras, 2006).
It could be argued that wilderness in fact does not truly exist, for even
the most remote parts of the Earth are affected by people, for example
through global change processes, past land use, hunting, water abstraction
or introduced species. The idea of wilderness is also one that many people
support, but few people visit or have a thorough understanding of, and
is itself a ‘social construct’; that is an idea about nature, rather than a
quantifiable fact. Designated areas of wilderness are often very similar to
nearby undesignated areas.
Environmental ethics
Related to the concepts of wilderness and of ecocentric environmentalism
is the idea of environmental ethics, which considers the ethical
relationship between people and the natural environment. Environmental
ethics are considered to be linked back to Aldo Leopold and more recently
Arne Naess (see ecocentric viewpoints section above), although many
individuals have their own code of environmental ethics regardless of
these or any other authors. Within environmental ethics there is a debate
as to why the environment is important, which aspects have most value
(usually considered both economically and non-economically, as intrinsic
value). Ethical debates in the field of society and the environment
include (after Attfield, 2003):
23
68 Society and the environment
• Extinction: Is it right for people to cause extinctions? If not, to what
lengths should we go to try to prevent them from occurring?
• Should potentially dangerous animals (eg. bears, alligators, mosquitos)
be allowed to live in the same areas as people, or controlled and
removed?
• Should forests be exploited to allow for farmland, when there is a
rising need for more food and a demand for timber, or should natural
forests be conserved for their own sake?
• Should plants and animals with no known value to people (utilitarian
value) be conserved?
• Personal ethics are important in decision-making, as our choices of
food, clothes, energy supplier, holiday and means of transport all
impact upon the environment.
Activity
To what extent does your own choice of lifestyle reflect environmental ethics? Is there
anything you would not buy, for ethical reasons, for example a bearskin coat, or an
Amazonian hardwood chair? If so, why not? Would environmental ethics change what
you eat?
Environmental sociology
Beginning in the 1970s, when the environmental movement grew and
environmental issues reached the political agenda, academic studies
outside ecology and environmental science became involved in studies of
the relations between society and the environment. Included in this was
the beginning and growth of environmental sociology, defined as the study
of the interactions between the natural environment, social behaviour
and social organisations of various types (Irwin, 2001). This was a
slight change from the previous ‘Sociology of the Environment’ whereby
environmental issues were addressed by the methods and approaches of
sociology. Most sociological theory up to this point viewed social processes
as distinct from the natural environment, although perhaps related to
human and built environments.
Within environmental sociology, the social factors that lead to
environmental problems are studied. Some findings of relevance to this
subject are (after Redclift and Woodgate, 1997; Dunlap, 2002):
• Social constructions of environmental issues are of great importance
in determining what is considered an issue, what is studied at all and
what is unknown, or unpublicised, and what responses are considered
possible. The role of science and scientific organisations is questioned.
• Local constructions of environmental issues are also important, as
environmental problems are considered very differently by different
people. These different perceptions affect the possible solutions to
issues, as well as whether they are considered problems at all.
• The role of capital and capitalism in environmental problems has often
been emphasised, along with deficiencies in economics and political
processes as ways of solving them.
• The role of gender and the sometimes conflicting aims of men and
women in environmental issues.
• Problems of environmental degradation are often linked to poverty and
inequality. These inequalities work on local and global scales (see land
degradation issues in Chapter 6 for example).
24
Chapter 2: Environmental systems and society
2,4,5-T
Some of these aspects are illustrated by the discussion below of a pesticide
(and pollutant), 2,4,5-T.
This discussion is summarised from Irwin (2001). The case of 2,4,5T (2,4,5-Trichlorophenoxyacetic acid) involves a synthesised chemical
agent, used as a herbicide in agriculture, especially in rice cultivation
but elsewhere also. The chemical was thought to cause health effects,
particularly skin problems, with less certain links to birth defects including
serious abnormalities, and cancer. From the 1970s through into the 1980s
campaigns by environmental and workers groups reduced and then
stopped the production and use of the chemical in the US and Europe,
except under very particular uses and in a highly regulated manner.
This case highlights a number of social aspects to environmental problems.
The licensing of pesticides in the UK was controlled by the Advisory
Committee on Pesticides (ACP), which was in dispute with the trade union
that represented farmworkers. The ACP reviewed the ‘facts’ as reported to
them and concluded that there was no real evidence of the chemical being
the cause of the reported problems. The ACP suggested that 2,4,5-T was safe
when used ‘in the recommended way and for the recommended purposes’.
This highlights first that a structure of ‘scientific experts’ and ‘lay’ users
of the chemical existed, and that this structure created problems of
communication and decision-making, because the chemical was frequently
‘misused’, leading to problems. Rather than considering the farmworkers
as experts in the everyday use of the herbicide, the Committee appeared
to consider them ignorant or uninformed. Each side ‘constructed’ technical
evidence in a way that made their case, even though several scientists
supported the farmworkers’ case. The Committee’s delay in responding
was an example of ‘naïve sociology’ being embedded in their analysis; a
belief that the guidelines for use would be strictly followed.
Further social aspects are apparent in the 2,4,5-T case. Public opinion was
more solidly behind a ban when it emerged that 2,4,5-T was a component
of ‘agent orange’ as used as a defoliant in the Vietnam war, and the accident
at a chemical plant in Seveso, Italy, in 1976. In addition, 2,4,5-T itself is not
particularly toxic, but an accidental biproduct and contaminant causes the
problems, tetrachlorodioxin, which is produced accidentally when 2,4,5-T
is poorly manufactured. Regulation of manufacturing, training of chemical
engineers, and quality control systems are all involved in this issue.
Activity
Select one environmental issue from this syllabus, and consider how it has been, or could
be, approached by environmental scientists, economists, politicians and sociologists.
•• What is distinctive about the role of sociology?
•• Can any one discipline on its own (a) explain, and (b) propose solutions to the issue
chosen?
Political ecology and social ecology
Related to environmental sociology but not the same thing, are the
fields of political ecology and social ecology. Political ecology is a crossdisciplinary study of the social, political and economic factors that both
create and respond to environmental problems. Within this, the roles of
states, multinational corporations, organised labour and pressure groups
are considered, as well as economic arguments. For example, the trade
agreements under the control of the World Trade Organisation (WTO)
25
68 Society and the environment
have environmental impacts indirectly by affecting the trade and demand
for farm products, wood or fish, for example. The reverse approach is
also taken – examining how environmental actions impact upon people –
the restrictions placed on those within national parks, or the benefits of
ecotourism.
Social ecology is the study of society and the environment through a largely
anti-capitalist viewpoint, and often points out the link between poverty and
those affected by environmental problems, and wealth and those creating
them. Social ecologists would argue that the problems of poverty, inequality
and environmental degradation can only be solved together.
A reminder of your learning outcomes
By the end of this chapter and the relevant reading, you should be able to:
• describe the relationships between people and the environment, through
the processes of agricultural and industrial development
• outline and quantify the major global environmental cycles
• discuss changes in environmental perception, and explain different types
of ‘environmentalism’
• outline the role of environmental sociology and related sub-disciplines in
understanding environment–society interaction.
Sample examination questions
1. Describe and quantify the global water cycle. Explain how
human action alters the cycle, and how this can lead to
environmental problems.
An approach to the question
The answer should start by explaining the importance of water, both
to natural systems and to human societies, and therefore lead into an
explanation of the critical importance of the hydrological cycle. Outline
also the ‘cycles’ approach to understanding human intervention and
natural systems.
A description of the cycle may be enhanced by the use of a diagram showing
the main storage components – the atmosphere, oceans, rivers, lakes and
swamps, ice and groundwater. The diagram might also show the major flux
components of the cycle – precipitation to oceans or to the Earth’s surface,
evaporation to the atmosphere from the surface storage elements. Quantify
the storage in, and flow between, each component of the cycle model.
Pickering and Owen (1997), Park (2001) and Jackson and Jackson (2000)
all provide suitable examples.
At this point, take time to assess the information you have included. For
example, do all the sources agree on the rates of transfer, or the amount of
water in the atmosphere? How do these figures vary over the course of a
year, or the course of a century? How have they been measured?
Human intervention can be dealt with component by component. If it is
assumed that human-induced global warming is a reality,17 then increases
in evaporation rates might be expected, and reductions in ice volumes.18
More definite and quantifiable changes occur on smaller scales. Drainage
of swamplands and farmland increases the rate of run-off to rivers and
oceans, and reduces the soil and groundwater storage components. Use of
river water, dam construction, deforestation and changes to atmospheric
composition all alter the hydrological cycle.
26
17
See Chapter 5.
See Kemp (2004);
Chiras (2006).
18
Chapter 2: Environmental systems and society
Next, assess the relative impact of human intervention against the
background of natural scales and variability. Is it significant – is it an
environmental problem? (You need to define an environmental problem.)
Part of the answer to this is in the scale of analysis. Human impact has
caused loss of lakes and drying-out of rivers, and in other areas floods.
You should include some examples. The Yangtze River and Aral Sea are
included in several texts. On a global scale however, is there any evidence
of a significant change to the water cycle?
2. Describe O’Riordan’s ecocentric and technocentric
attitudes to environmental concerns. How would an
individual from each viewpoint respond to a plan to drill
exploratory oil wells in an area of natural forest?
Understanding the question
The aim of the question is first to test your basic understanding of the
terms and O’Riordan’s ideas. The second part is not asking you to relate
known facts, but to think about the answer to the first part in a given
situation. If you know an example of oil development in a forest area or
elsewhere this will be useful, but it is not essential in order to answer
the question.
27
68 Society and the environment
Notes
28
Chapter 3: Environmental pollution
Chapter 3: Environmental pollution
Essential reading
Jackson, R.W. and J.M. Jackson Environmental science: the natural environment
and human impact. Chapters 14–16.
Kemp, D.D. Exploring environmental issues: an integrated approach.
Pickering, K.T. and L.A. Owen An introduction to global environmental issues.
Further reading
Alloway, B. and D.C. Ayers Chemical principles of environmental pollution.
(Glasgow: Blackie Academic and professional, 1993) [ISBN 0751400130].
Clark, R.B. Marine pollution. (Oxford: Clarendon Press, 1997) third edition
[ISBN 019850070X].
Elsom, D.M. Atmospheric pollution: a global problem. (Oxford: Blackwell, 1992)
[ISBN 0631173080].
Elsom, D.M. Smog alert. Managing urban air quality. (London: Earthscan, 1996)
[ISBN 1853831921].
Farmer, A. Managing environmental pollution. (London: Routledge, 1997)
[ISBN 0415145155].
*Harrison, R.M. Pollution: causes, effects and control. (Cambridge: Royal Society
of Chemistry, 2001) fourth edition [ISBN 08540446216].
Harrison, R.M. (ed.) An introduction to pollution science. (Cambridge: Royal
Society of Chemistry, 2005) [ISBN 0854048294].
Hester, R.E. and R.M. Harrison Air quality management. (London: Royal Society
of Chemistry, 1997) [ISBN 0854042350].
*Hill, M.K. Understanding environmental pollution. (Cambridge: Cambridge
University Press, 2004) second edition [ISBN 0521527260].
Houghton, J. Global warming: the complete briefing. (Cambridge: Cambridge
University Press, 2004) third edition [ISBN 0521528747].**
Markham, A. A brief history of pollution. (London: Earthscan, 1996)
[ISBN 1853832138].
Mason, C.F. Biology of freshwater pollution. (Harlow: Longman, 2002)
fourth edition [ISBN 0130906395].
Miller, G.T. Living in the environment: principles, connections and solutions.
(Belmont: London: Brooks/Cole 2006) fourteenth edition. See also other
editions [ISBN 9780534997281].
Weber, E. Air pollution: assessment methodology and modeling (Nato challenges
of modern society, volume 2). (New York: Plenum, 1982).
World Health Organisation Environmental Health Criteria 3: Lead. (Geneva:
WHO, 1977).
(*) indicates the most highly recommended texts.
Learning outcomes
By the end of this chapter and the associated reading, you should be
able to:
• describe the nature, causes and impacts of environmental pollutants
affecting air, water and soil
• discuss the relationships between different pollutants and the natural
environment and know examples of the different types
• outline possible solutions to the sources and impacts of pollution
problems (see also Chapter 7).
29
68 Society and the environment
Introduction and definitions
Since humans first used natural resources, pollution has been caused
by the extraction and processing of materials, the disposal of waste and
by the human population itself. The aim of this chapter is to examine
pollutants in the atmosphere, water and soils, to assess their sources and
impacts and discuss potential solutions.
Pollution can be defined as any liquid, solid or gaseous matter that is
introduced into the environment to levels above those that are normally
found without human intervention. Any output of material from human
activity can be seen as a pollutant. A more functional definition of
pollution, adapted from that provided by Weber (1982),1 is ‘the presence
of substances resulting from the activities of man or from natural
processes, causing adverse effects to man and the environment’. A
thorough definition from Elsom (1992), suggests that although pollutants
may be present, it is what they do that define them as such. His definition,
adapted here to be applicable to all pollutants, can be stated as follows:
The presence of substances, or energy, in such quantities and of such
duration liable to cause harm to human, plant, or animal life, or changes
in the weather and climate, or interference with the comfortable
enjoyment of life or property or other human activities (adapted from
Elsom, 1992: 3).
Pollution of soils and sediments, water, atmosphere, and our own food
and habitats has occurred on spatial scales from micro-scale to global.
There are various complicating factors, such as the interaction
between pollutants, different timescales of cause and effects, and
in many cases scientific uncertainty as to the nature of pollution.
Different animals and plants respond to a pollutant in different ways. To
study these causes, processes and effects is demanding, and a structure to
such a study is suggested (1–5) below. It is not intended as an exercise to
complete now, but rather as a guide as to how to structure your reading
and notes about pollution.
1. Examine the nature of the pollutant. What makes it a pollutant?
Reach an understanding of the scientific background to its operation in
the environment.
2. Examine the sources of the pollutant. Where has it come from, why and
when?
3. Study the effects it has, both on the natural environment and on
human well-being.
4. Review the means by which the pollutant can be, or has been,
controlled, or its effects mitigated.
5. A broader view can then be attempted which looks at the economic and
political background to the pollutant’s origin, control and management.
This structure will allow an understanding of the pollutant itself, and the
systems within which it operates. A case study is presented below (carbon
monoxide), followed by a worked example question on lead pollution.
This approach should be used to study a wide variety of pollutants, and
some important ones are listed in the rest of this chapter. Once this basis
has been established, it will be possible to treat environmental pollution
in a more integrated way. Many of the causes and solutions are similar for
different pollutants.
30
Weber, E. Air
pollution: assessment
methodology and
modeling (Nato
challenges of modern
society, volume 2). (New
York: Plenum, 1982)
1
Chapter 3: Environmental pollution
Pollution of the atmosphere
The effectiveness, or harmfulness, of a pollutant depends upon the duration
of exposure of the organism to the pollutant, and on the concentration
of the pollutant. This can be illustrated by examining one atmospheric
pollutant, carbon monoxide (CO). CO is an odourless gas, and forms
part of the carbon cycle.2 More than half (1,500 Tg [terragrams]) of the
atmospheric CO produced each year comes from human sources, compared
to 1,200 Tg from natural sources. Under our definitions of a pollutant,
then, CO satisfies the criteria of exceeding normal levels. The effects on
humans, animals and plants at normal levels (measured in ppm = parts per
million) are thought to be minimal, and even at the enhanced background
levels encountered in cities the effects may be slight. However, at more
concentrated levels, and given prolonged exposure, severe health effects
have been recorded. CO is absorbed through the lungs and reacts with
haemoproteins, especially with haemoglobin, in the blood. The main
role of haemoglobin is to take oxygen from the lungs to the rest of the
body and release it there. CO interferes with this process by reducing the
oxygen-carrying capacity of the blood and inhibiting the release of oxygen.
For every 1 ppm of CO in the atmosphere, given prolonged exposure,
0.165 per cent of the body’s haemoglobin will be combined in the form of
carboxyhaemoglobin.3 If a person were exposed to 30 ppm atmospheric CO,
therefore, for eight hours, their carboxyhaemoglobin levels would reach 4.5
per cent. Reference to the table below shows that this would have moderate
to severe health effects. Under all the definitions, CO is a pollutant.
Concentration
Effects
<1%
Minimal effect.
1–2%
Affects behavioural performance. Aggravates symptoms
in people already suffering cardiovascular disease, causes
severe stress for those with weak hearts. Risk of foetal oxygen
deficiency
2–5%
Impairment of vigilance, impairment of time-interval
discrimination, impairment of visual functions, severely
aggravates symptoms of cardiovascular patients, increased
angina risk.
5–10%
Cardiac and pulmonary functions impaired, increasedsymptoms
as for 2–5%.
>10%
Headaches, fatigue, drowsiness, reduced work capacity, coma,
respiratory failure and death.
2
See Chapter 2.
Elsom, 1992; Harrison,
2001.
3
Table 3.1: Effects of blood carboxyhaemoglobin levels on human health.
Sources: World Health Organisation, 1972; Elsom, 1992; Elsom, 1996.
Under all the terms of reference cited above, CO is a pollutant. Natural
sources of CO include the disassociation of CO2 in the atmosphere, natural
fires and volcanic activity. It is global in terms of production and distribution. The main anthropogenic (human-caused) source is the combustion of carbon-rich fuels, the most important being vehicle exhaust emissions. Studies have shown that levels are highest close to roads and at
road intersections, and that levels rise and fall on a daily basis in time with
traffic volumes. Those people most at risk are traffic attendants, car park
workers and tollbooth cashiers, as well as truck or taxi drivers who have
prolonged exposure to high concentrations. The amount of CO taken into
the lungs depends to some extent on respiration rate, so running or cycling
31
68 Society and the environment
can increase the intake. Walking may reduce the intake rate, but will increase the time-exposure assuming that journey time is increased.
Global levels are currently around 70–80 ppb (parts per billion), concentrated
at 100 ppb in the northern hemisphere4 and rising at a rate of between 0.7
and 1.4 per cent annually. The effects on a global scale are thought to be
a contribution to global warming, although relatively minor and indirect
when compared to carbon dioxide and methane (see Chapter 5; Kemp;
2004; Houghton, 2004). CO also possibly contributes to stratospheric ozone
depletion by reducing the quantity of hydroxyl radicals in the atmosphere
which would otherwise remove the ozone-depleting gases such as CFCs.5
Control of CO levels can take a number of forms, which illustrate the
possible responses to this type of pollutant. The most direct is to reduce
the output, either by reducing the amount of fuel combusted or by
cleaning the exhaust gas output, for example by using a catalytic converter
on motor vehicles. Reducing the amount of fuel used can be done either by
reducing the amount of journeys undertaken, or by reducing the amount
of fuel used per journey, or by a combination of these two. A more indirect
way of reducing the pollution risk is to avoid the association between
people, especially those in the higher-risk groups, and the places and times
of highest CO concentration. 6
The broader social and political view of CO pollution shows a pattern that
is common to many air pollution problems in the 1990s, that of a close
link to car ownership and road vehicle numbers, especially in urban areas.
CO has reached dangerous levels in the cities of ‘developed’ countries in
the last 50 years, and in industrialising countries in the last 20. Levels in
some less industrialised countries are high only in the capital cities and
then only at peak times. Attempts to reduce road traffic have been few,
mostly restricted to the pedestrianisation of small areas in city centres.
Car-restricting policies are faced by the political difficulty of restricting
or taxing car use, and the economic effects that such policies may have.
Additionally, motor manufacturers and fuel producing companies have
political leverage, and governments themselves rely on the income from
taxes on fuel, cars and vehicle parking.
The air pollution level in any one place depends upon the amount of
industrial activity, the concentration of vehicles, and the raw materials
being processed. In addition, natural factors interact to make humanproduced pollution issues worse. Particulate matter can be increased by
erosion of fine sand from desert areas, or by the input of smoke from forest
or range fires, which may be natural or anthropogenic. The influence
of meteorological conditions can be crucial. Strong winds can remove
pollutants from an urban area, but increase pollution levels elsewhere, and
temperature inversions, where cool air is trapped beneath warmer air, can
lead to higher concentrations of atmospheric pollution. Los Angeles and
Mexico City are infamous for this problem. The interaction of sunlight,
high temperatures and air pollutants can lead to the production of socalled ‘photochemical smog’, or ‘petrochemical smog’. These terms
describe the high concentrations of ozone, nitrous oxides and VOCs that
occur in cities with a high traffic volume and in certain conditions (Elsom,
1992). Ozone itself is often at least as highly concentrated in rural areas,
as the photochemical reaction required for it to form can take several
hours, by which time the pollution has drifted downwind. Also, certain
pollutants also found in the urban area have the effect of removing ozone
thereby reducing levels. This is quite a different problem from that of a
depletion of stratospheric ozone, dealt with in Chapter 5.
32
4
Zander, R., P. Demoulin,
D.H. Enhalt, U. Schmidt,
and C.P. Rinsland. ‘Secular
increase of the total vertical
column abundance of carbon
monoxide above central
Europe since 1950.’ Journal of
Geophysics Research. (1989)
94 (D8), 1021–8.
See Chapter 5; Jackson and
Jackson (2000).
5
6
See Elsom (1992;
1996); Farmer (1997);
Hill (2004).
Chapter 3: Environmental pollution
Activity
What policies have been suggested, or implemented, to reduce pollution from road
traffic? These issues are discussed by Markham (1996), Elsom (1996) and by Miller (2006)
and others.
Other airborne pollutants with global and local significance are listed in Table 3.2 below,
along with an introduction to their sources. An approach as outlined above will help you
to answer examination questions in this field and a worked example follows.
Pollutant
Sources
Particulates, including dust, smoke, PM 10
(particles less than 10 m), PM 2.5
Coal, oil-fired power stations, industrial
boilers, waste incinerators, domestic
heating, diesel vehicles, construction,
mining, quarrying, cement manufacturing.
Sulphur dioxide, SO2.
Coal and oil burning in power stations,
industrial plants and homes, waste
incinerators, diesel vehicles, metal
smelters, paper manufacturing.
Nitrogen oxides, NOx, NO3, NO4..
Fossil-fuel power stations, industrial
boilers, waste incinerators, motor vehicles.
Carbon monoxide, CO.
Motor vehicles, fuel combustion.
Volatile organic compounds (VOCs) (e.g.
Benzene, Toluene)..
Petrol engines, leakage at petrol stations,
paint manufacturing.
Toxic organic micropollutants, including
dioxins, polychlorinated biphenyls,
aromatic hydrocarbons.
Waste incinerators, coke production, coal
combustion, smokeless fuel plants. .
Toxic metals, including cadmium, lead.
Leaded petrol, metal processing, waste
cadmium, lead.incinerators, oil and coal
combustion, battery manufacturing,
cement and fertiliser production
Toxic chemicals, including ammonia,
chlorine, fluoride .
Chemical plants, metal processing,
fertiliser ammonia, chlorine, fluoride
manufacturing.
Ozone, O3
Secondary pollutant, formed from NOx
and VOCs
Radionuclides.
Nuclear reactors, nuclear waste.
Table 3.2: Major air pollutants and their sources (excluding CO2, CFCs and CH4,
considered in Chapter 5).
Sources: Elsom, 1992; 1996; Harrison, 1996; Miller, 1996; Hill, 1997.
Transboundary pollution
An increasing issue in pollution studies (including studies of the origin
of pollutants, but also in terms of impacts and policy-makers) is that
of transboundary pollution. This term is used to describe marine
and especially air pollution that passes across national and regional
boundaries. An example is arctic haze, the pollution that accumulates
in the far north of both North America and Eurasia and over the Arctic
Ocean, especially in winter. This pollution demonstrates that some types of
pollution can spread globally.
A particular issue is the atmospheric pollution problem in south east Asia,
known as the Asian Brown Cloud (ABC). This is a mass of pollutants,
including soot, sulphur and nitrogen oxides and dust particles, visible
at ground level, from aircraft and from satellites. This affects several
33
68 Society and the environment
countries in the region, and the Indian Ocean, with pollutants of gas
and particles travelling over 3,000 km. Sources of the haze are greatly
increased numbers of vehicles, fossil fuels in power stations and industry,
forest fires, the burning of agricultural waste, and inefficient cookers
(source: Kemp, 2004). Another regional problem is transboundary
pollution within the People’s Republic of China (between provinces), and
between China and neighbouring states. Acid rain in Europe and North
America are further examples.
Transboundary pollution causes a number of specific problems:
• It is hard to find the source in some cases, or prove the origin.
• International agreements are needed to reduce pollution levels and
these can be hard to agree or enforce.
• There is often a dilemma between the economic and industrial growth
of one region and the environmental impacts in another.
Activity
Research the origins and composition of the ABC. How is it measured and monitored?
Can the source be clearly identified? What measures can be taken to reduce this pollution
problem, and what difficulties are likely to arise? Kemp (2004) and the UNEP report at
(www.rrcap.unep.org/issues/air/impactstudy/index.cfm)
Water pollution
Water is widely distributed, mobile, and essential for life of all kinds.
In places it can be problematic due to excess and in others it is too
scarce. Less than one per cent of the world’s water is present as fresh
water in lakes and rivers, 97 per cent is in the oceans and the rest in the
atmosphere in gas form, in polar or mountain ice, or in underground
aquifers (rock strata containing water).7
For centuries water bodies have been a convenient waste disposal site for
human activities, as well as sources of power, irrigation, a cleaning fluid
and a means of transportation. At times, however, these uses of water
have conflicted with the other, arguably most important human use of
water, as drinking water. Pollution of rivers and lakes has affected human
health and caused millions of deaths worldwide (Table 3.4) and caused
considerable disruption of natural systems. As well as receiving pollutants
directly through waste disposal, cleaning or power generation, water
bodies, especially oceans, receive airborne pollutants on a large scale.8
The effects of pollutants on water depends on a number of factors:9
• Concentration of pollutants. For some pollutants, even a
small trace can cause a great impact (for example organophosphate
insecticides), whereas others (for example, iron) can be tolerated by
most ecosystems in low concentrations, and the water may remain
useful for people.
• Timescale of contamination. If a pollutant is released into a river
continuously, even at times of low flow, it is likely to have a more
significant impact than a shorter discharge at the same concentration.
• Mixture of pollutants. Pollutants may interact in ways that increase
their effectiveness and increase toxicity.
• Volume and movement of water. Disposal of materials into water,
deliberately or inadvertently, causes the pollutants to become diluted.
Large water bodies have a greater capacity for absorbing pollution, and
34
See Jackson and
Jackson (2000).
7
8
See Clark (1997).
See Mason (2002); Hill
(2004).
9
Chapter 3: Environmental pollution
rivers with a high discharge are more efficient diluters than those with
low flow rates. It can take 10–100 years to replace the water in lakes,
which means that pollutants remain in the water longer, whereas rivers
replace the water at any one point constantly.
• Sensitivity of the natural systems. The state of the natural
environment before contamination is crucial to the effectiveness of
a pollutant. Acidic pollution, for example, has been shown to have
more effect in areas where lakes are already acidic, and where there
is a low capacity for neutralising the acid in the soils and rocks of the
surrounding environment (see example question).
• Use of the water post-contamination. The worst cases of human
health impact by water pollutants have occurred where the water, once
contaminated, is used as drinking water. If polluted waters are not used
by people, then the effects can be limited to the disruption of natural
systems.
Pollutant group
Sources
Oxygen-demanding wastes,
including animal and human
sewage
Sewage effluent from towns and cities,
agricultural run-off including animal wastes,
industrial waste water from paper mills, food
processing.
Plant nutrients, including nitrates
Phosphates from detergents used in and
phosphates household or industrial cleaning,
nitrates from fertilisers and from atmospheric
deposition.
Acids, H2SO4, HCL, HNO3
Acid rainfall, dry deposition of airborne pollutants,
mine water drainage.
Toxic metals, including lead and
mercury
Mine water drainage, deposition from airborne
sources including industrial and vehicular sources.
Oil and oil derivatives
Drilling operations, waste disposal into drains and
sea, cleaning tanks and ships’ bilges, oil tanker
and pipeline spills.
Pesticides
Direct application, agricultural run-off, forest
run-off.
Polychlorinated biphenyls (PCBs),
209 different species produced
Sewage effluent, waste incineration, leaching
from toxic waste dumps and landfill waste
disposal sites.
Radionuclides
Nuclear weapons testing, nuclear industry, waste
disposal.
Heat
Coolant waters from power stations and other
industry.
Table 3.3: Major water pollutants and their sources.
Several of the major pollutants of water are the same as those affecting
the atmosphere. Pollutants such as lead and other metals can be produced,
moved, stored and remobilised. For example, in lead mining areas of
northern England, 100-year-old spoil heaps left after processing of orebearing rock are currently being eroded by rivers, remobilising the lead
into the water. Sediment is then deposited on the floodplain further
downstream, where it dries out before blowing in the wind in the form
of fine dust. Some of the lead-bearing sediments are removed from the
river and deposited in the estuary or sea shelf sediments, where the
lead contaminates mud-dwelling organisms. As these organisms are
35
68 Society and the environment
preyed upon by wading birds, the lead builds up (bioaccumulates, or
biomagnifies) in the birds, leading to lead poisoning. This example
shows how persistent, non-degradable or slowly degrading pollutants can
have a complex life-cycle.10
Water pollution and disease
See Harrison (2005);
Hill (2004); Alloway and
Ayres (1993).
10
A problem in many parts of the world is the contamination of drinking or
bathing water with human waste. This leads to the spread and recycling of
many infectious and parasitic diseases.
Disease
Effects
Typhoid fever
Severe vomiting and diarrhoea, can be fatal if untreated
Dysentery
Acute diarrhoea, can be fatal in infants if untreated
Cholera
Severe vomiting, diarrhoea, dehydration, can be fatal if
untreated
Enteritis
Vomiting and diarrhoea
Infectious hepatitis
Severe headache, fever, jaundice, enlarged liver, rarely fatal
Polio
Severe headache, fever, paralysis in body and limbs, can be
fatal
Amoebic dysentery
Severe diarrhoea, abdominal pains, fever, chills, can be fatal
if untreated
Giardia
Diarrhoea, fatigue
Bilharzia
Debilitating illness, skin rash, anaemia, chronic fatigue,
(Schistosomiasis) haemorrhaging, not often fatal
Hookworm infestation
Heavy infestation can be fatal
Table 3.4: Diseases spread by polluted water.
Source: Jackson and Jackson (2000).
Most cases of infection arise because there is no clean water supply and no
effective sewage treatment or removal system. Many recent and current
examples are linked to urbanisation in Less Developed Countries (LDCs),
which has often been rapid and unplanned, with many communities
lacking basic infrastructure. Other cases arise in refugee centres or
after warfare when systems have been damaged. In many cases, the
diseases typical of water pollution are treatable, but the societies where
water management is not developed are often poor and medical care is
insufficient. A first stage in addressing a contamination problem is often
to remove sewage via pipes or manually into a river. This can have severe
effects downstream if the river is used for bathing, washing or drinking,
or is prone to flooding occupied areas.
Soil pollution11
Pollutants released into air or water are dispersed and diluted. Soils,
however, are more stable and usually stationary, and hence act as
accumulating stores, or sinks of certain chemicals. The reaction of soils
to pollutants depends to a large extent on the soil properties. Soil is
composed of a mixture of fluids and gases in pore spaces, mineral material
and organic material. These proportions vary under different conditions
and with depth. For students studying the 147 Physical geography
course, the basics of soil science should be familiar, but otherwise the
introductions in a basic text are recommended.12
36
Many texts concentrate
on air and water pollution.
For soils and sediments,
Alloway and Ayres (1993)
is thorough, although
some sections assume a
working knowledge of
chemistry principles.
11
See Park (2001), Briggs,
D. et al. (1997) or 147
Physical geography course
texts.
12
Chapter 3: Environmental pollution
Most soils contain colloids, small particles often composed of a mixture
of clay minerals and humic material. These colloids are able to adsorb
the inorganic and organic pollutants that come into contact with them,
that is they become chemically bonded to the pollutants. Reactive
pollutants in water passing down through a soil, therefore, are likely to
be transferred to the soil, becoming part of the colloidal adsorption
complex. When soils are waterlogged, less percolation is likely, and
hence less transfer, but reactions in the soil can still take place, altering
the form of the adsorption complex. Desorption can also occur under
appropriate conditions, releasing the pollutants back into the percolating
soil water.
Microbial organisms are also involved in the adsorption, storage,
transformation and release of soil pollutants. Their role is linked to oxygen
availability and their presence and abundance is related to nutrient
status. Water availability is also important in determining the status of
the bacteria, and the amount of movement of materials down, or up, the
soil profile. It is clear, then, that the factors influencing soil pollution are
extremely complex, and include internal factors such as soil properties,
as well as external factors, such as the input of pollutants from the
atmosphere.13
When pollutants reach the soil they are either adsorbed with varying
strengths at the surface or in the top soil, or they are washed further
down. This process can be rapid, for example in sandy soils under
frequent rainfall conditions, or slow, in less porous soils and/or under
drier conditions. Some pollutants may be leached from a soil (removed),
whereas others may be illuviated, moved down the profile where they
re-accumulate. Concentrations of soil pollutants are most likely in the
topsoil due to input from the surface, increased rates of adsorption and
in dry climates the upward movement of soluble soil components due to
evaporation.
Pollutant group
Sources
Toxic metals, including lead, cadmium,
arsenic, chromium, vanadium.
Industrial processes, mine drainage water and
mine waste, vehicle emissions
PCBs
Industrial processes, waste incineration, via
airborne pollution
Salts, including common salt (NaCO3)
and calcium carbonate (CaCO3).
Salinisation of soils due to irrigation,
especially using seawater or in arid areas,
or where groundwater is used.
Pesticides, including DDT, Malathion,
Glyphosate.
Deliberate application to control weeds and
insect pests. Indirect input from plants and
animals.
See Ayres and Alloway
(1998); Harrison (2001,
2005); Hill 2004;
Jackson and Jackson
(2000).
13
Table 3.5: Major soil pollutants and their sources.
Metals, metal oxides and metal hydroxides form an important part of the
natural ecosystem, and are generally very abundant in soils. Aluminium
(Al) for example, comprises 8.2 per cent of the Earth’s crust, and is a
common element in clay minerals. Most metals occur only as trace
elements, a few parts per billion, but can have essential roles. Lack
of zinc, molybdenum or copper can cause growth or fertility defects
in mammals. However, too much of a normally rare metal can cause
toxic effects including brain or growth abnormalities, or death. Tests on
mammals have shown that cadmium (Cd), mercury (Hg) and selenium
(Se) are toxic in low quantities and lethal in higher doses.14
Between 1 and 2 mg/
kg bodyweight (Alloway
and Ayres, 1993).
14
37
68 Society and the environment
Pesticides and pesticide residues in soils are a source of disruption of
natural systems and also a potential threat to human health. They are
often abundant in soils due to being applied directly to the soil, or
indirectly to plants, into the atmosphere or in animal treatment, but
become part of the soil complex. Bioaccumulation of DDT, Dieldrin and
Aldrin in birds of prey is an example of the risks involved. Generally at the
top of the food chain, birds of prey can accumulate toxic levels from the
tiny quantities in each insect, mammal or small bird eaten. Biodegradation
rates for DDT are slow.
Activity
Find examples of particular pesticides and their impacts on the environment, their
residence times in soils, and their use in agriculture. Try and adopt a balanced approach in
answering essay questions – the benefits of pesticides in food productivity and reduction
in insect-borne disease balanced against the environmental impact and health risks of
pesticide use.
Pollutants in soils are important because they accumulate to dangerous
levels, and enter the animal and human food chains via vegetation growth.
Contaminated soils can also affect groundwater, which, when used for
water supplies for human use, can again lead to health effects.
The treatment of contaminated soil is generally difficult and expensive.
Removal of all the contaminated material is the most common way of
treating contaminated land (although not treating it at all is actually
the most common ‘management option’ used). In these cases land is
marked, fenced and not used. Where soil is removed, the underlying
substrate may lack fertility, and can take many years to recover for use
as agricultural land. The removal option is most commonly used where
land is needed for other uses, particularly industry or housing. Another
problem is what to do with the toxic soil. Options include land-filling and
dumping at sea, both of which have environmental impacts and financial
costs. Bioremediation can also be used in certain cases. This works by
growing plants that selectively remove the contaminants from the soil, and
then incinerating the plants. The removal of metals can be enhanced by
the addition of bacteria and by aeration of the soil. This process may take
tens of years, however, and can lead to incomplete removal.15
Activity
Use the five-point approach to studying pollutants outlined at the beginning of this
chapter to study soil contamination. Additional changes to the chemical composition of
contaminants while in the soils system should be included.
Acid deposition and acid rain
In some instances, air, water and soil pollution issues merge due to
the pathways of substances through the environment. Examples are
common throughout the discussions above, but a good example is the
role of sulphur (S) as a pollutant. Many texts include a discussion of acid
rain, and some books address only this issue. When reading about acid
rain, however, note that rainfall is naturally acidic (pH approx. 5.6–5.7),
and that the issue is enhanced acidity. Sulphur and nitrogen pollution
occur also by dry-deposition direct from the atmosphere without rain
or snowfall, and in the form of cloud and mist (occult deposition). See
example question for further information.
38
Alloway and Ayres
(1993).
15
Chapter 3: Environmental pollution
A reminder of your learning outcomes
By the end of this chapter and the associated reading, you should be able to:
• describe the nature, causes and impacts of environmental pollutants
affecting air, water and soil
• discuss the relationships between different pollutants and the natural
environment and know examples of the different types
• outline possible solutions to the sources and impacts of pollution
problems (see also Chapter 7).
Sample examination questions
1. Discuss the sources and effects of lead (Pb) in the
environment and discuss how levels can be reduced.
Understanding the question
There are a number of anthropogenic sources of lead in the atmosphere. By
‘discuss’ the question requires you to address these in more than just a list,
but also explain why the lead is used and released into the environment.
Outline
Lead is a pollutant of water, air and soils that has been shown to have
toxic effects. While other metals (for example cadmium, nickel, mercury,
chromium and vanadium) are equally or more toxic, they are generally
limited spatially to metal processing or waste disposal sites. Lead however
is, and has been for at least 2,000 years, widely used and dispersed in
the environment. Roman bones have lead levels 10 times higher than
those found now, due to the use of lead pipes for water and lead cups for
drinking. Those working in or near lead mines at the time, and up until
the twentieth century, were even more at risk.16
16
See Markham (1996).
The most common source now is vehicle fuel, in which lead has been an
additive since the 1940s. The lead is in the form of lead alkyles, tetraethyl
or tetramethyl lead. Seventy-five per cent or more of the lead added
to petrol is emitted from the exhaust pipe, having performed its main
function of preventing the fuel in the cylinder combusting too early. When
emitted, the lead is in a small, dispersed form that is easily inhaled or
incorporated into plants, dust and watercourses.
Lead is also used in paints, although this has now been cut back in most
More Developed Countries (MDCs). When the paint is manufactured,
and then when it is stripped or burned at the end of its useful life, lead is
remobilised into the environment, either as dust or in water. Other sources
include lead water pipes, which although replaced by copper or plastic
in many places are still in position in older houses in Europe and North
America. The majority of the lead that causes environmental problems,
particularly human health effects, comes from car fuel, and this has
been shown by the success of the US reduction programme. Lead levels
in Americans’ blood averaged 16 µg/dl (microgrammes per decilitre) in
1976, but by 1980 had been reduced to 10 µg/dl, coinciding with the
phasing out of leaded petrol.
The effects of lead on human health when in large quantities is well
known, but less so its effects when in lower concentrations. Examples
of these effects are increased rates of hyperactivity, distraction and poor
performance amongst school children, seen as clear evidence that lead
39
68 Society and the environment
levels in the blood impair brain functions. Recent studies suggest that even
levels as low as 10, the average for Western European and Indian cities in
the early 1990s, may have subtle effects on children’s brain performance.
Higher levels can cause anaemia, dysfunction of the brain, acute or chronic
encephalopathy, while kidney damage can occur with levels of 60–70ug/dl
in children or 80 in adults.17
Describe some examples of lead pollution studies and effects, and place
them in the overall context that the question requires.
WHO (1977); Elsom
(1992; 1996); Miller
(2006).
17
To reduce lead levels there are steps that can be taken, but not without
financial cost. Pipes can be replaced with other types, and paints covered
over, or removed and disposed of in a controlled manner. Examples of how
to reduce levels of environmental lead are discussed by Elsom (1992). The
most obvious way to reduce Pb pollution appears to be the elimination of
lead additives in fuel. This began in 1976 in the US, yet in most countries
lead is still used, although unleaded and diesel alternatives have grown
significantly. Where lead is still used, it can be reduced by increasing fuel
efficiency or by reducing journeys. Although scientific uncertainty exists
regarding the source of all lead in humans, a proportion of that ingested
through food, water and drink may itself have originally come from
airborne sources, and therefore originally from vehicle emissions.
The costs involved would be to producers of fuels, paints and lead products
(lead shot, weights, roofing material), who would be required to develop
alternatives, and to the lead producers, miners and mining companies,
who may be forced out of business. Costs may be passed on to consumers
and government, through compensation to companies that lose out,
unemployment pay and lost tax revenues. See also www.epa.gov/lead.
2. Describe the mechanism and causes of freshwater
eutrophication, and discuss the impact on human and
natural systems.
Understanding the question
The question asks for a description of the causes and mechanisms,
rather than the more involved discussion in the previous question.
The second part, however, requires some depth of knowledge regarding
the effects of eutrophication. The mechanism is the process by which
eutrophication occurs, and the causes in this case are the events that lead
to the pollutants reaching the water. Limit the answer to freshwater (rivers
and lakes) rather than marine systems.
Outline
Eutrophication (derived from the Greek eutrophus meaning ‘well-fed’)
occurs when certain organisms are over-nourished and grow to excess
(compared to normal, or natural conditions). This causes a reduction in
the availability of oxygen to other organisms, and can result in the loss
of many species from the water body. It is a common problem in lakes
and some rivers in many areas of the world. Eutrophication can occur
naturally, as organic matter builds up in the lake through time. This
process is enhanced by a number of human actions and pollutants, and
this acceleration to levels beyond those occurring naturally is termed
accelerated or cultural eutrophication.
The first stage of the mechanism is the input into water of nutrients that
are in quantities that make them pollutants. The nutrients can be in the
form of phosphorus, usually in the form of the phosphate anion (PO4),
Nitrate (NO3) or Ammonia (NH4).18 This causes excessive growth of algae,
40
See Jackson and
Jackson (2000); Mason
(2002).
18
Chapter 3: Environmental pollution
cyanobacteria and some water plants. The level of dissolved oxygen in
the lake water, both at depth and in the surface waters, is reduced as the
algae die, fall back to the bottom and are decomposed by aerobic bacteria.
Oxygen depletion kills fish and other aquatic animals. In addition, light
is prevented from penetrating the surface, reducing the photosynthetic
potential at depth and eliminating some water plants (Mason, 2002;
Miller, 1996). Masses of algae then die, and accumulate on the bottom
of the lake or form a floating mat, decomposing through the actions of
anaerobic bacteria. These bacteria produce toxic hydrogen sulphide gas,
which further pollutes the water.
The sources of phosphorus and nitrogen pollution are sewage effluent, both
treated and untreated, run-off from farm land where fertilisers have been
applied, and run-off from urban catchments where detergents and washing
powder in waste water reach storm drains. Airborne nitrogen pollution
is also important. Run-off from farmland where livestock are intensively
farmed can also cause nitrogen (N) and phosphorus (P) pollution. Many
lakes receive airborne nitrogen compounds originating from motor vehicles
and industrial processes, possible hundreds of kilometres distant. Mining
operations, construction sites, paper, food and fertiliser plants all discharge
nutrient-enriched water. The problem has often been made worse by the
proximity of urban areas and industry to water, and the reduction in flow
rates, and therefore reduced dilution, caused by abstraction of water for
drinking and industry, and by dams and locks.
The effects on natural systems are severe – total loss of fish can occur,
an increase in total biomass but a decrease in species diversity. Animals
and birds dependent on the water supply for food (fish, invertebrates
or plants) are also reduced or eliminated from the area. The effect on
humans is less direct. The loss of fish can reduce food production and
amenity value and increased costs are incurred by clearing waterways and
lakes of algal blooms. High N levels in drinking water are directly toxic.19
19
See Mason (2002) .
You need to illustrate this section with examples, including the places,
timescale and species involved. Lake Washington, USA, and The Great
Lakes, USA and Canada, are well known examples.
Management options for eutrophic water can be divided into two
categories, remedial and preventative. Remedial measures include:
• pumping oxygen into the water
• physical removal of algae and excess weed
• minimising algal growth by using biocide chemicals.
Preventative measures include:
• reducing the use of phosphate-based cleaning agents
• redirecting or increasing the removal rate of nitrates and phosphates
during sewage treatment
• timing the release of waste waters to avoid low flow, warm water
situations.
Agricultural inputs from fertilisers or livestock waste can be harder to
control without reducing crop yields, but the following are all helpful
measures:
• using less fertilisers of all types
• spreading manure at strategic times
• buffer zones around water courses.
41
68 Society and the environment
You should be able to explain that each management option has
advantages and disadvantages, both economically and environmentally.
The impact on human and natural systems is influenced by the
management option taken – these options include doing nothing.
3. ‘Acid rain is directly responsible for the death of lakes and
trees in northern Europe, yet the cause is clear and the
solutions are available.’ Critically discuss this statement.
Understanding the question
There are two parts to the required answer, one that explains the process
of acid rain and its impact on lakes and trees, and the second, which
discusses the cause and possible solutions. A good answer will be factually
accurate, and address whether acid rain is directly responsible for the
death of lakes and trees, and whether the causes are clear. As with many
environmental issues, scientific uncertainties exist and the question asks
you to address this.
Outline
Acid rain is the term used to describe the enhanced acidity of rain,
measured by reduced pH, due to the combination of atmospheric
pollutants and atmospheric water. It is caused mainly by sulphur, with a
contribution also from nitrogen, adding to the effect of carbon dioxide
naturally present in the atmosphere. Sulphur oxidises readily to form
SO2 and then further, in the presence of sunlight, to SO3. SO2 reacts
with atmospheric nitric oxide (NO) to produce sulphuric acid (H2SO4).
Simplified, SO2 or SO3 can react with H2O (water) or OH (hydroxyl
radical) to form H2SO4.20 Inputs of S into the atmosphere result in
sulphuric acid in liquid droplets. Sulphur is also produced by volcanic
eruptions, and is usually present even in the unpolluted atmosphere, but
at concentrations below the risk limit of approximately 0.5µg/g. Nitrogen
oxides, NO, NO2 or NO3, originating from various heating and combustion
sources21 combine with OH to form HNO3 during daylight hours.22
Having introduced the chemical background to what acid rain is, assess
the evidence for its impact. Forest ‘dieback’ has been recorded in the
US, western and northern Europe, eastern Europe and the former Soviet
Union. Coniferous trees appear to be more afflicted, or show the symptoms
more readily. Damaged trees lose needles (coniferous leaves), are stunted
in growth and have limited root systems, making them more prone to
drought, wind-throw and nutrient deficiency. Links to acid deposition have
been shown by geochemical techniques, principally analysing rainfall and
soil conditions, by experimentation, and by the partial recovery of forests
when emissions have been reduced.
The ‘death of lakes’ refers to the effects of acidic deposition on aquatic
life. Fish populations were noted to be declining in Sweden and the US, in
remote areas away from any industrial zones, in the early 1960s. Analyses
of lake and river waters found pH levels below 4.7, thought to be a critical
level for salmonid river fish (trout and salmon species). Acidity affects the
operation of hormones, enzymes, lungs and gills, not only of fish but all
organisms. Precipitation levels of pH less than 3 were recorded in the UK
and in Canada, again in remote areas hundreds of kilometres from sulphur
sources. Research has shown that acidity increases in soils, caused by acid
rain, not only reduce the pH levels of water but also releases adsorbed
metals from soil profiles, which are then leached into the freshwater
system. Aluminium in particular, toxic at many levels of the ecosystem in
42
See Jackson and
Jackson (2000); Harrison
(2001); Alloway and
Ayres (1993).
20
See Table 3.2; Elsom
(1992).
21
22
See Harrison (2001).
Chapter 3: Environmental pollution
enhanced quantities, is believed to be a cause of ‘dead’ lakes, which are
clear and blue, but lacking the usual life. At least 6,000 lakes in Norway
and Sweden and 2,000 lakes in the US and Canada are thought severely
affected.23
Doubts still remain, however, because other pollutants accompanied the
acid rain in many instances, and some forests appear to have remained
unaffected. This is due to the effect of local geological conditions, and the
buffering capacity of soils with a high calcium content. For example,
CaCO3 (calcium carbonate), reacts with H ions (the acidic component of
rain or soil water) to produce Ca (calcium), H2O (water) and CO2 (carbon
dioxide) – effectively neutralising the acidity. Constant input of acid rain
weakens the buffering capacity in areas where CaCO3 is present but not
abundant, producing lesser acidic effects, and where CaCO3 is abundant,
all the acidic deposition can be neutralised by the soil, although foliage
defects may still occur.24
Although afforestation, land use changes, peat bog drainage and natural
processes have all been blamed, strong evidence from the study of lake
sediments has shown a link in time between the onset of acidification and
sulphur use in power stations and iron and steel works.25 This case has
been strengthened by the identification of soot particles in the same lake
sediments. The causes are slightly more complex – not only are emissions
of N and S the cause, but also the use of tall chimneys to remove the
pollutants from the local area, and the use of high-sulphur coal or other
sulphur-rich fuels. The next question, then, is are solutions available?
Assuming for the time being that the biggest problem is caused by
coal-fired power stations, possible options include:
23
See Miller (2006).
See Miller (2006),
Jackson and Jackson
(2000).
24
25
See Roberts (1998).
• reducing the output of power stations by saving electricity
• reducing the pollutant output by using cleaner fuels, by washing
the fuel, using less sulphur-rich coal, or changing over to gas-fired
power stations
• changing to ‘renewable energy sources’
• reducing output by fitting ‘scrubbers’ – filters using sprays of lime-rich
water, to chimneys
• treating the affected area with the addition of lime to topsoil.
You should be aware of the environmental and economic costs and
benefits of these options that limit their ‘availability’.
Each option is linked also to political factors. Reducing the use of
electricity involves lifestyle changes or replacement equipment, and each
power generating system, like each fuel type has a business interest and
an employed labour force. The fitting of scrubbers is slowly going ahead in
most of the MDCs, as is a switch away from sulphur-rich coal as the main
fuel. Dependency on oil or natural gas however, often causes a dependency
on imported fuel. Rapidly industrialising countries, notably India and
China, are increasing their coal use as it is locally abundant and relatively
cheap and newly acidified lakes and damaged forests can be expected in
the coming decades.
Sulphur as a pollutant has other effects. It causes damage to buildings,
and plant crops, principally through acidifying water vapour and rainfall,
and is also toxic to humans. Breathing difficulties are experienced above
1.5 µg/g. The limit for prolonged exposure is 5 µg/g. People who already
suffer from asthma or bronchitis are at risk if exposed for one day at only
0.5 µg/g.
43
68 Society and the environment
Notes
44