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.