Chapter 1: Environmental science

Section 1.1: Understanding Our Environment

Environmental science is the study of how humans

interact with their environment.

The term environment

refers to everything

that surrounds

us.

Forty years ago the average citizen did not think very much about

the environment – however, in the past few decades, many people

have begun to wonder if we might paying too high of a price for our

comfortable living.

FACTS * 218 million Americans live

near polluted waters.*Upon the arrival of the pilgrims, a squirrel could jump from tree to tree clear across the country

without touching the ground once.

*By the year 2020, global warming will cause a 145% rise

in mortality.

Three Major Environmental Issues

•Resource Depletion

•Pollution•Extinction

Resource depletion

Natural resources are any natural substances that organisms use.

Two types of resources:

• Renewable resources: water, sunlight, wind

• Nonrenewable resources: trees gold, oil

A resource is depleted when a large part of it has

been used up!

Pollution is the introduction of

harmful levels of chemicals or

wastes into the environment.

Extinction is the permanent loss of a

species.

When thinking about environmental problems, it may help to visualize

the biosphere – the thin layer of life surrounding the Earth.

The biosphere extends from the surface of the Earth to about 5

miles above and below the surface.

Within the biosphere exists two types of

countries: developed and developing

countries.

Developed countries such as the U.S. and Canada have citizens that have high average

incomes and are highly

industrialized.

Developing countries such as Mexico and Thailand, are

less industrialized

and have a lower average income.

Many environmental problems can be linked to increasing

human populations and increasing demand on natural

resources.

Population crisis: occurs in developing countries

where the human populations are growing too quickly for the region

to support.

Consumption crisis: occurs in developed countries where people use up,

waste or pollute natural resources faster than they

can be replaced.