ENVIRON 102 Lecture Notes - Lecture 8: Ecological Footprint, Hispania, Improved Sanitation
4 May 2018
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Department
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Human Population Change & Demography
2.19.15 Lecture Notes
World population has risen sharply
Global human population was < 1 billion in 1800
Population has more than doubled just since 1964
We add >200,000 people every day (~78 million/year)
Currently ~ 7 billion
I. Why care: relationship to environment
Ecological footprint
Based on area required to produce energy, food, consumables, and building materials
Use of resources in relation to our capacity
Human population and use of resources may be inverse
Global distribution of ecological footprints
Is this distribution a problem? Why or why not?
Whose fault is depletion of resources?
Will improved standard of living worldwide exacerbate environmental problems?
Does aid to developing nations exacerbate population growth?
Developing nations will develop to a point at which the ecological footprint will become larger
But to what extent will there be improvements in efficiency?
More use of resources will cause cost of resources to go up and we’ll try to find alternatives
Role of developed and developing nations – should we cut down on our own energy use?
II. Historical perspectives
Edward Deevey proposed that human population change had gone through several phases
associated with the development of key technologies that transformed human relationships with
ecosystems.
(A) Geographic dispersal, cultural tools
Early humans
o Language and communication
o Tool making
o Fire
Adaptation to different environments
Redefined the nature of adaptation and how information is transmitted from generation to
generation
(B) Agriculture
~10,000 year BP (before present) – earliest agriculture
Domestication of plants and animals
Transformation of ecosystems – simplification to concentrate production into things humans want
and need
Cultures varies:
o Nomadic herders using domestic animals to extract energy from ecosystem
o Sedentary agronomists – cultivating crops and building permanent cities
Permanent settlements support complex economies and leisure – development of written
language, arts, and culture
Life nonetheless generally brutish
Disease widespread and evidence of significant population fluctuations within regions
Historical data (mostly tombstone inscriptions) from Roman times allow calculation of life
expectancy (0-400 AD)
find more resources at oneclass.com
find more resources at oneclass.com
o Rome 23 years
o Roman Spain 37 years
o Roman Africa 45-47 years
o Why the difference?
o Lead poisoning in water in Roman Empire
o Slaves and prisoners of war?
o Infectious disease, high density, sanitation problems
Was this progress? Diamond reading
o As hunter gatherers, their diet was actually more balanced, while agriculture lowered their
life spans
o Agriculture led to higher density of people and a higher carrying capacity
o Only elite improved standards of living, but an examination of bones, disease and health
was worse for the rest of the people because of agricultural diets
(C) Industrial Revolution
Another major change in ecosystem: fossil energy added to solar energy, boosting ecosystem
production
Major use of fossil fuels (stored solar enegy)
Increased agricultural production
o Cultivation/harvest technology
o Fertilizers (nitrogen in particular)
o Pesticides
o Irrigation
Greatly improved nutrition and medical advances increase life expectancy
Historical changes in human populations: an ecosystem perspective
Sunlight Plants Herbivores Carnivores
People competing with carnivores, herbivores with tools and smarts
People simplify ecosystems, eliminate competitors and increase production by investing their own
energy in cultivation and husbandry
People add fossil energy (=stored sola energy) to solar energy through mechanization, fertilizers,
biocides, and irrigation – simplification continues
We now manage 1/3 of all primary productivity on Earth (ability of photosynthetic organisms to
create carbon)
What is the carrying capacity?
o 3 times the current size? Would that result in 100% management of primary production?
Historical perspective on consequences: Rev. Thomas Malthus
1789: An essay on the principle of population
Idea that there are limits to human population growth (comparing populations of colonies to
Europe)
Explored effects of changes in populations, food supplied, and prospects for human happiness
Compared population growth in the American colonies with that of Europe
Malthus attributed Europe’s lower population growth rate to misery and vice (used
religious/philosophical reasoning)
Three key insights
o Exponential growth
o Resource limitations
o Connection of population change to the quality of human life
Estimates of population change and consequences
Improved models and improved understanding
Lot of estimated population growth models
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Global human population was < 1 billion in 1800. Population has more than doubled just since 1964. We add >200,000 people every day (~78 million/year) Currently ~ 7 billion: why care: relationship to environment. Based on area required to produce energy, food, consumables, and building materials. Use of resources in relation to our capacity. Human population and use of resources may be inverse. Developing nations will develop to a point at which the ecological footprint will become larger. More use of resources will cause cost of resources to go up and we"ll try to find alternatives. Edward deevey proposed that human population change had gone through several phases. Historical perspectives associated with the development of key technologies that transformed human relationships with ecosystems. (a) geographic dispersal, cultural tools. Early humans: language and communication, tool making, fire. Redefined the nature of adaptation and how information is transmitted from generation to generation (b) agriculture and need.
