Welcome to the third edition of the Gale Environmental
Encyclopedia! Those of us involved in writing and production
of this book hope you will find the material here interesting
and useful. As you might imagine, choosing what to include
and what to exclude from this collection has been challenging.
Almost everything has some environmental significance,
so our task has been to select a limited number of topics
we think are of greatest importance in understanding our
environment and our relation to it. Undoubtedly, we have
neglected some topics that interest you and included some
you may consider irrelevant, but we hope that overall you
will find this new edition helpful and worthwhile.
The word environment is derived from the French
environ, which means to “encircle” or “surround.” Thus, our
environment can be defined as the physical, chemical, and
biological world that envelops us, as well as the complex
of social and cultural conditions affecting an individual or
community. This broad definition includes both the natural
world and the “built” or technological environment, as well
as the cultural and social contexts that shape human lives.
You will see that we have used this comprehensive meaning
in choosing the articles and definitions contained in this
volume.
Among some central concerns of environmental science
are:
Ohow did the natural world on which we depend come to
be as it is, and how does it work?
Owhat have we done and what are we now doing to our
environment—both for good and ill?
Owhat can we do to ensure a sustainable future for ourselves,
future generations, and the other species of organisms on
which—although we may not be aware of it—our lives
depend?
The articles in this volume attempt to answer those
questions from a variety of different perspectives.
Historically, environmentalism is rooted in natural history,
a search for beauty and meaning in nature. Modern
environmental science expands this concern, drawing on
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almost every area of human knowledge including social sciences,
humanities, and the physical sciences. Its strongest
roots, however, are in ecology, the study of interrelationships
among and between organisms and their physical or nonliving
environment. A particular strength of the ecological
approach is that it studies systems holistically; that is, it
looks at interconnections that make the whole greater than
the mere sum of its parts. You will find many of those
interconnections reflected in this book. Although the entries
are presented individually so that you can find topics easily,
you will notice that many refer to other topics that, in turn,
can lead you on through the book if you have time to follow
their trail. This series of linkages reflects the multilevel associations
in environmental issues.
As our world becomes increasingly interrelated economically,
socially, and technologically, we find evermore
evidence that our global environment is also highly interconnected.
In 2002, the world population reached about 6.2
billion people, more than triple what it had been a century
earlier. Although the rate of population growth is slowing—
having dropped from 2.0% per year in 1970 to 1.2% in
2002—we are still adding about 200,000 people per day, or
about 75 million per year. Demographers predict that the
world population will reach 8 or 9 billion before stabilizing
sometime around the middle of this century. Whether natural
resources can support so many humans is a question of
great concern.