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Biodiversity
Why are we losing it?
Available at http://planet.uwc.ac.za/nisl/Biodiversity/
BCB 705:
Biodiversity
We have a responsibility…
To ourselves!
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Biodiversity is an important part of our environment.
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Biodiversity loss directly affects human well-being.
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There are those who are not willing to believe that humans are
causing biodiversity loss.
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Environmentalists present evidence that human actions at all levels
of society are causing biodiversity loss.
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Our responsibility is to find out for ourselves:
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How we affect the environment as a species,
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How we affect the environment individually,
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How we can reduce our individual impact on the environment.
This chapter outlines the reasons why humans as a species have a
negative impact on the environment.
Anthropogenic causes of biodiversity loss
Debt
Economic
Growth
Legislation
Attitude to
Biodiversity
Global
Trade
Population
Growth
Poverty &
Migration
Habitat
Degradation
Low Economic Value
of Biodiversity
Military
Urbanization
Property
Rights
Subsidies
Biodiversity
Loss
Food Supply
& Industry
Habitat Loss
& Fragmentation
Direct causes of extinction

The following cause extinction by directly using a species,
using habitats and using resources leading to decreased
numbers of populations, population size and sometimes
individual fitness.
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Habitat destruction and
fragmentation
Habitat degradation
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Invasion by exotic
species
Pollution
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Climate Change
Overexploitation
Agriculture and forestry
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Agriculture causes the destruction, fragmentation and degradation
of natural habitat and thus loss of biodiversity. The contributions of
the following two aspects of agriculture are briefly discussed:

Domestication
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Increasing yield
Forestry causes natural habitat
destruction, fragmentation and
degradation and thus loss of
biodiversity. The following
aspects of forestry may contribute to the loss of biodiversity:
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Species selection
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Harvesting methods
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Domestication
Clear felling of forest
Aquaculture and fisheries
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Aquaculture causes habitat destruction and habitat degradation
and thus biodiversity loss in both marine and freshwater habitats.
The following aspects contribute to biodiversity loss:
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The provision of infrastructure and technology,
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Waste products,
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The introduction of exotic species,
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Selective breeding.
Fisheries cause habitat degradation and habitat destruction in both
marine and freshwater habitats and thus biodiversity loss. The
following aspects contribute to biodiversity loss:
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Improved technology,
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Harvesting methods,
Marine fisheries are threatened by the loss of rivers,
mangroves, estuaries, coastal wetlands and coral reefs.
Industry and urbanisation
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Industry may be defined as any group of businesses that use the
same method of generating profits or alternately as a section of
economic production dedicated to manufacturing.

Industry is the means of converting natural capital into selected
goods and services. This process involves both habitat destruction
and habitat degradation. Causing pollution is cheap but cleaning
up pollution is expensive and would lower profits.

Industry promotes urbanisation and vice versa.
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Urbanisation refers to the expansion of urban areas or the
expansion of the proportion of the population in urban areas or the
increase of this proportion over time. This expansion results in
habitat destruction and habitat degradation.

Urban areas get their resources from elsewhere. This means that
urban people are not in close association with the resources that
they are using which affects their attitude to resource use.
Attitudes
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Attitudes to biodiversity are linked to culture.
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Attitudes, opinions and tastes are formed. They may be altered by:
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Internal social interactions,
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External influences.
Marketing is a tool used to influence people’s opinions by
presenting information and/or propaganda.
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Companies that harm the environment market
misinformation to confuse the public into supporting them against changes in legislation, etc.
Environmentalists use marketing to promote the
retention of biodiversity through conservation.
As the distance/separation from a resource increases, the concern for that resource decreases.
The failure of economics to value biodiversity
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Several factors cause economics not to value biodiversity
appropriately:
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The nature of the benefits of natural
resources;
Unequal access to property rights;
Markets do not reflect all natural
resource use;
Economics fails to consider the high risk value of biodiversity
loss;
Economic indicators (e.g. the Gross National Product) are
flawed.
The result of this failure to value biodiversity is that conservation is
seen as a burden not an opportunity.
Legislation, subsidies and taxes
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Both companies and governments select countries globally to
avoid legislation (environmental, financial or social) that hampers
their activities.
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Most of the oceans are not protected by any
national legal jurisdiction or effective international agreements for biodiversity protection.
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The Kyoto Protocol (on reducing carbon
emissions) does not protect biodiversity.
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Subsidies are used encourage environmentally
harmful activities.
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Taxes on environmentally harmful industries are
a potential tool for reducing biodiversity loss.
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Vested economic interests make changes in governmental policy
difficult.
Property rights and access regulation
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Property rights concern controlling access to a resource, obtaining
it or guaranteeing it – i.e. the rights to whatever value is derived
from the use or exchange of a resource.
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Social status affects access to property rights. Over-consumption
is more damaging than poverty.
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Property rights are more easily available to urban males working in
the formal economic sector than to rural people.
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Property rights are often granted for the conversion of natural land
to ‘productive’ use.
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The lack of property rights causes overexploitation.
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Open access causes overexploitation.
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Communal access control is an effective way of regulating resource
use.
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Access to information affects resource use.
Conversion, specialisation and globalisation
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Conversion refers to the shifting of capital from one form to
another.
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The law of economic specialisation indicates that productivity
increases as the homogeneity (uniformity) of production methods.
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Globalisation covers the complex economic, political, social and
technological changes that increase the interdependence and
interaction of entities in disparate locations.
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Globalisation causes the spread of specialised products and
changes in human attitudes.
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Globalisation separates resource management from the resource
users which removes local feedback mechanisms.
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Specialisation and globalisation are synergistic.
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Conversion, specialisation and globalisation promote
homogenisation of the biosphere.
Debt – the driver of the global economy
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Debt is what is owed. Normally, this refers to money but it is not
limited to money.
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The International Monetary Fund attaches conditions such as
structural adjustment programs to its loans.
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Critics say that the demands made in structural adjustment
programs (see the Additional Notes for this slide) cause economic
stagnation and retard social stability.
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The national debt of developing countries limits their development
and harms biodiversity by:
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Overexploitation of natural resources for foreign currency,
Decreasing the money available for spending on the
subsistence agriculture sector.
The link between national debt and biodiversity loss in tropical
forest countries is so strong that a $(US) 5 billion debt reduction
reduces annual deforestation by between 250 and 1000 km2.
Poverty and migration
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Poor people:
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Have a higher than average population
growth,
Depend on the local environment for
survival,
Usually do not have control over the
resources they use.
The above factors force people to migrate to:
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Urban areas,
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Natural areas.
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Migrants do not know the resources of the areas they migrate to.
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Waves of human migration in the past are linked to waves of
extinction.
Economic growth
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Economic growth may be defined as
increase in the ability to supply
goods and services for human use.
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Economic growth is normally measured by an increase in indicators such
as the Gross National Product (GNP),
the Gross Domestic Product (GDP)
and the Gross World Product (GWP).
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Economic growth may be achieved by:
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Population growth (because this increases the number of both
producers and consumers),
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Increased per capita (per person) consumption,
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Both of the above.
Economic growth does not reduce poverty.
Human population growth
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The human population is growing exponentially at a rate of 1.35%
per year. At this rate it takes:
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1.6 years to add 129 million people –
the number killed in all wars fought
in the past 200 years;
3.4 years to add 276 million people –
the size of the United States’
population in 2000;
15 years to add 1.26 billion people – the size of China’s
population in 2000.
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Humans already use 40% of the Net Primary Productivity (NPP) of
the terrestrial earth. How much more will we be able to use?
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Family planning is crucial to stabilizing human populations.
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Educating women and providing them with safe means to control
fertility reduces the birth rate.
Concluding remarks
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Governments do not adequately protect biodiversity.
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Both the global economy and the human population are expanding
causing increased resource demand.
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Reducing poverty is essential to preserving biodiversity.
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The expanding economy resembles a pyramid scheme. Pyramid
schemes eventually collapse and the lower levels lose their
investments.
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The economy reflects the power of human greed.
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All anthropogenic damage to the biosphere (and hence
biodiversity) is the result of human choice.
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Every individual has the power of choice. The choices of
individuals affect the preservation or loss of biodiversity.
Chapter 1 Biodiversity: what is it?
Chapter 2 The evolution of biodiversity
Links
to other chapters
Chapter 3 Biodiversity: why is it important?
Chapter 4 Global biodiversity and its decline
Chapter 5 Biodiversity: why are we losing it?
Chapter 6 Extinction: past, present, future
I hope that you found chapter 5 informative and that you will
enjoy chapter 6.