Environmental Problems, Their Causes and Sustainability

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CHAPTER 1

• Environmental Problems, Their Causes and
  Sustainability

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Living in an Exponential Age

• Exponential growth - a quantity increases by a
  fixed percentage of the whole in a given time
• Environmental problems are interconnected
• population growth
• wasteful use of resources
• destruction and degradation of wildlife habitats
• extinction of plants and animal
• poverty
• pollution

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Living Sustainably

• Sustainability - ability of specified system to
  survive and function over time
• Natural resources are our natural capital
  depletion of capital is living unsustainably
• Our demands on earths resources and natural
  processes is increasing exponentially

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Growth and the Wealth Gap

• Doubling time (70 / growth rate) related to
  exponential growth
• Human activities have disturbed 73 of habitable
  area of planet
• Gross national product (GNP) is a measure of
  countrys economic growth

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Growth and the Wealth Gap - 2

• Economically developed countries
• are highly industrialized and have high GNP
• have 20 of population and 85 of wealth
• use 88 of resources produce 75 of waste
• Developing countries
• are low to moderately industrialized and have low
  GNP
• have 80 of population and 15 of wealth
• use 12 of resources

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Is Current Economic Growth Sustainable?

• Not sustainable because
• limits imposed by earths finite supplies of
  resources
• environments capacity to absorb, detoxify and
  recycle wastes
• Sustainable development - environment can
  continue to
• supply and renew resources
• absorb or break down wastes

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What is Wealth Gap

• Large families in developing countries b/c
• children are seen as economic security
• many children die early
• Their habitats are polluted and dangerous
• 49,000 premature deaths / day
• Many die from malnutrition and contaminated
  drinking water

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Resources

• Ecological resources habitat, food, water and
  shelter
• Resources classified as
• renewable, potentially renewable or nonrenewable
• some are directly available e.g. air some are
  available only with technological ingenuity

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Potentially renewable resources

• Replenished in hours to decades
• Living organisms, water, air, and soil
• Biological diversity (biodiversity) types
• genetic diversity - variation in genetic makeup
  among individuals in species
• species diversity - variation among organisms in
  habitat
• ecological diversity - variation of biomes

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Potentially renewable resources

• Sustainable yield - rate at which resource can be
  used w/o reducing available supply
• Otherwise - environmental degradation
• urbanization of productive land
• waterlogging salt buildup in soil
• excessive topsoil erosion
• deforestation habitat destruction
• pollution

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What are nonrenewable resources?

• Energy resources cannot be recycled
• coal, oil, natural gas and uranium
• Metallic mineral (hard, usually crystalline,
  naturally formed) resources - can be recycled
• iron, copper, and aluminum
• Nonmetallic mineral resources - difficult or
  costly to recycle
• salt, sand, clay, and phosphates

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What are nonrenewable resources? - 2

• Economic depletion - cost of extraction and use
  exceed economic value - leads to
• effort to find more
• recycle or reuse existing supplies
• use and waste less
• effort to develop substitute
• wait for more to be produced

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What are nonrenewable resources? - 3

• Recycle - collect and reprocess a resource
• Reuse - use over and over in same form
• Reserves - known deposits of a given nonrenewable
  resource from which usable mineral can be
  extracted profitable at current prices

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Pollution

• Pollution is anything added to air, water, soil
  or food that threatens living organisms
• Pollution sources
• some are natural
• most are anthropogenic
• point sources are single and identifiable, e.g,
  smokestack
• nonpoint sources

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Harm Caused by Pollutants

• Disruption of life-support systems
• Damage to wildlife, human health and property
• Nuisances - e.g. loud sounds
• Factors determine severity
• chemical nature - how active or harmful
• concentration
• persistance

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Persistence of pollutants

• Nonpersistent or degradable by natural physical,
  chemical or biological processes e.g. sewage
• Persistent and slowly degradable, e.g. DDT and
  plastics
• Persistent and nondegradable e.g. lead and mercury

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What can be done about pollution

• Prevent pollutants from reaching environment
  (input pollution control)
• two incentive approaches carrot and stick
• Pollution cleanup (output pollution control)
  three problems
• temporary bandage
• often just transfers pollutant
• often expensive

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Environmental and Resource Problems

• Underlying causes
• rapid population growth
• little pollution prevention and waste reduction
• simplification of degradation of earths natural
  life-support systems
• poverty --gt resource use for survival
• economic political systems fail to encourage
  earth-sustaining economic development
• failure to consider environmental cost
• domination and managing of nature

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Environmental Problems and Root causes

• Three factor model - impact of population on a
  given area depends upon
• population size - P
• average of units of resources used / individual
• amount of environmental degradation and pollution
  produced
• Population x affluence x technonlogy
  environmental impact (technology may have
  positive or negative impact)

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Cultural changes and sustainability

• Human cultural changes
• Hunter-gatherer societies - earlier ones survived
  through environmental wisdom advanced
  hunter-gatherer impacted environment more
• Agricultural revolution - cultivation of plants
  animals slash burn and shifting cultivation
• Industrial revolution - machines depended on
  nonrenewable fossil fuels --gt urbanization
• Information revolution

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Present Course - Sustainable?

• Will ingenuity and technology lead to
• pollution cleanup
• substitutes for scarce resources
• expansion of earths ability to support humans
• Instead - focus on
• pollution and waste prevention
• protection of habitats (not just species)
• environmental restoration
• resource conservation