Environmental Engineering Reference
In-Depth Information
Developing Countries
x
x
=
Consumption
per person
(affluence,
A
)
Technological impact per
unit of consumption (
T
)
Environmental
impact of population (
I
)
x
x
=
Population (
P
)
x
x
=
Developed Countries
Figure 1-13
Connections:
simplified model of how three factors—number of people, affluence, and tech-
nology—affect the environmental impact of the population in developing countries (top) and developed
countries (bottom).
the same lifetime resource consumption as 2 children in a
typical U.S. family.
Some forms of technology, such as polluting facto-
ries and motor vehicles and energy-wasting devices,
increase environmental impact by raising the T factor
in the equation. Other technologies, such as pollution
control and prevention, solar cells, and energy-saving
devices, lower environmental impact by decreasing
the T factor. In other words, some forms of technology
are
environmentally harmful
and some are
environmen-
tally beneficial.
Until about 12,000 years ago, we were mostly
hunter-gatherers who typically moved as needed to
find enough food for survival. Since then, three major
cultural changes have occurred: the
agricultural revolu-
tion
(which began 10,000-12,000 years ago), the
indus-
trial-medical revolution
(which began about 275 years
ago), and the
information-globalization revolution
(which
began about 50 years ago).
These major cultural changes have significantly in-
creased our impact on the environment. They have
given us much more energy and new technologies with
which to alter and control more of the planet to meet our
basic needs and increasing wants. They have also al-
lowed expansion of the human population, mostly be-
cause of increased food supplies and longer life spans.
In addition, they have greatly increased the resource
use, pollution, and environmental degradation that
threaten the long-term sustainabilityof human cultures.
1-6 CULTURAL CHANGES AND
SUSTAINABILITY
Major Human Cultural Changes
Since our hunter-gatherer days, three major
cultural changes have increased our impact on
the environment.
Evidence from fossils and studies of ancient cultures
suggests that the current form of our species,
Homo
sapiens sapiens,
has walked the earth for only 60,000
years (some recent evidence suggests 90,000-195,000
years)—less than an eye-blink in this marvelous
planet's 3.7 billion years of life.
Eras of Environmental History
in the United States
The environmental history of the United States
consists of the tribal, frontier, early conservation,
and modern environmental eras.
The environmental history of the United States can be
divided into four eras. During the
tribal era,
5-10 million
