Download Chapter 2– Current Issues in Earth and

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Chapter 2– Current Issues in Earth and Environmental Science
Why is the Earth in trouble?
I. Introduction
A. What is Earth Science?
1. Definition – the study of the Earth, its history, its changes, and its place
in the universe
2. Branches of Earth Science
a. Geology – Earth’s origin, history, and structure
b. Meteorology – Earth’s atmosphere, weather, and climate
c. Oceanography - Earth’s oceans, including physical features, life forms,
and natural resources
d. Astronomy – the position, composition, size, and other characteristics
of the planets, stars, and objects in space
B. What is Environmental Science?
1. Definition – the study of the environments in which organisms live and how
they interact
2. An integrated science that includes elements of biology, chemistry, and
physics
3. Incorporates the impact of human activities, both planned and unplanned,
on the environment
II. History of Human Influence on the Earth
A. Hunter-Gatherer Society
1. Humans lived as hunter-gatherers from the time of their appearance on
Earth (60,000-90,000 years ago) until about 12,000 years ago
2. Ways of life:
a. Nomadic – moved around to find enough food for survival
b. Used earth wisdom – expert knowledge of natural surroundings (which
animals and plants can be eaten or used as medicines, where to find
water, how to predict the weather)
c. Used sunlight, fire, and muscle power for sources of energy
B. Agricultural Revolution
1. Occurred about 10,000-12,000 years ago
2. Ways of Life:
a. Settled into communities and had larger families; eventually
urbanization (development of cities) became practical – led to the first
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surge in human population growth
b. Cultivated plants and domesticated animals for human use
Ex. wheat, rice, cows, horses
c. Cleared vast amounts of land and used more non-renewable resources
C. Industrial Revolution
1. Began in the mid 1700’s
2. Ways of life:
a. Human population grew exponentially
b. Production, commerce, trade, and distribution of goods all expanded
rapidly
c. Became heavily dependent on non-renewable resources and fossil fuels,
resulting in increased air, water, and land pollution
III. Current Environmental Issues
A. Resource Consumption
1. Renewable vs. Non-renewable
a. Renewable resources are those that are inexhaustible on a human time
scale; ex. solar energy
b. Non-renewable resources exist in a fixed quantity and can be
exhausted; ex. fossil fuels, metals
c. Potentially renewable resources can be replenished, as long as they are
not used at a rate higher than the rate of replenishment;
ex.
trees, fertile soil, fresh water
2. The Tragedy of the Commons
a. Common property resources are those that are owned by no one (or
jointly owned by all users) but are available to all users free of charge
b. Examples include clean air, the open ocean, and public lands
c. The cumulative effect of many people exploiting a common property
resource will eventually exhaust or ruin it
3. More people = less resources An increase in the human population leads to the use of more natural
resources, however, the quantity of these non-renewable resources is
not increasing
4. Results in damage to the Earth from extraction and processing Natural resources must be obtained by mining the earth or seas, and
vast quantities of energy must be used to process these resources and
convert them to useful products
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B. Pollution
1. Definition – any addition to air, water, soil, or food that threatens the
health, survival, or activities of humans or other living organisms
2. More people = more pollution
a. Air pollution
i. Pollutants can be added to the atmosphere from automobiles,
industry, power plants, and other sources
ii. Air pollutants can lead to other problems such as ozone depletion,
acid precipitation, and climate change
b. Water pollution
i. Pollutants may be added to our water from direct sources such as
industries or animal waste
ii. Land pollution can become water pollution as it runs off into our
water or infiltrates into our groundwater
c. Land pollution
i. Pollutants may be added to our land directly (ie. pesticides)
ii. People produce large amounts of waste, much of it hazardous,
which may be considered pollution
C. Biodiversity loss
1. Biodiversity – the variety of different species on Earth, the genetic
variability of those species, and the variety of ecosystems in which
they exist
2. More people = less biodiversity
a. With human population growth, more land is needed for development
and agriculture
b. The main reason for loss of biodiversity is habitat loss or habitat
degradation.
IV. Sustainability
A. Definition – the ability of a system to survive and function over a
specified period of time
B. Our goal is to become a “sustainable society” – one that manages its
economy and population size without exceeding the Earth’s ability to absorb
environmental impact, replenish resources, and sustain humans and other
forms of life indefinitely
C. We can use Earth and Environmental science to learn more about how
nature sustains itself and how to mimic these processes in human cultures
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Tragedy of the Commons
Background:
In 1968, Garrett Hardin first coined the phrase, “Tragedy of the Commons”. This is a
situation that occurs when resources, such as the air we breath, the water we drink, and even the
fish we eat is shared by everyone, but no-one person takes personal responsibility for preserving
the availability of these resources for future use. The basic idea here is that if a resource is
“held in common” (meaning that the resource is owned by no-one, or owned by a group, all of whom
have access to the resource) for use by all, then ultimately that resource will be destroyed. Only
changes in human values and ideas of morality can overcome this ultimate destruction, according to
Hardin. The term tragedy in this case does not necessarily mean an unhappy ending, but an ending
that is inevitable and cannot be avoided.
An example of this principle is when cows are allowed to graze on common land. Since there
is no direct cost to using the land, individual ranchers are motivated to add to their herds in order
to increase their own personal wealth. However, each individual animal damages the pasture a small
amount. Ultimately these small amounts add up to a large amount of damage to the land, therefore
ruining it for all the animals and ranchers.
From 1950 to 1990, there was a fivefold increase in the world annual fish catch. An
increasing demand for fish coupled with environmentally damaging fishing practices are leading to
another tragedy of the commons. Roughly 70 percent of the planet’s marine stocks are fully or over
exploited, according to the Monterey Bay Aquarium’s Seafood Watch program.
Jared Diamond in his book Collapse describes in detail the collapse of civilizations that failed to solve the problem of
the Tragedy of the Commons. He writes of Pitcairn and Henderson Islands in the Pacific (page 120):
Many centuries ago, immigrants came to a fertile land blessed with apparently inexhaustible resources. While the
land lacked a few raw materials useful for industry, those materials were readily obtained by overseas trade with
poorer lands that happened to have deposits of them. For a time, all the lands prospered, and their populations
multiplied.
But the population of that rich land eventually multiplied beyond the numbers that even its abundant resources could
support. As its forests were felled and its soils eroded, its agricultural productivity was no longer sufficient to generate
export surpluses, build ships, or even to nourish its own population. With that decline of trade, shortages of the
imported raw materials developed. Civil war spread, as established political institutions were overthrown by a
kaleidoscopically changing succession of local military leaders. The starving populace of the rich land survived by
turning to cannibalism. Their former overseas trade partners met an even worse fate: deprived of the imports on
which they had depended, they in turn ravaged their own environment until no one was left alive.
Solutions
Tragedy is not inevitable. Jared Diamond described how some societies avoided tragedy, at least locally. The people
of Tikopia, Japan, and the New Guinea highlands saved their forests and the agrarian economy which depended on
forests. All limited their population to what could be sustained by their economy.
We Must Change Our Values: Mutual Coercion
Therefore, any solution requires that we, as a society, change our values of morality. For example, we may decide
that unlimited use of air is no longer morally acceptable. Hardin states one solution is "Mutual Coercion Mutually
Agreed Upon." We, as a society, agree that some actions are not allowed (the mutual agreement), and that violations
of the agreement leads to fines or prison terms (the Coercion). Thus, we have some restrictions on what can be put
into the air. The US Environmental Protection Agency regulates the amount of pollutants that can be released into the
air. Failure to comply with the regulations leads to fines or prison sentences.