Chapter 1Science and the Environment

1.1 Understanding Our Environment

What is Environmental Science? The study of the impact of humans on the environment.

The goal of environmental science To understand and solve environmental problems

Made up of many fields of study: One major field is ecology Ecology - the study of how living things interact with each other and with

their nonliving environment

What five major fields of study contribute to environmental science? 1. Biology 2. Earth Science 3. Physics 4. Chemistry 5. Social Sciences

Our Environment Through Time

Hunter Gatherers - people who obtain food by collecting plants and by hunting wild animals or scavenging their remains. Prairies - burn - hunt bison

The Agricultural Revolution Hunter-gatherers began to collect seeds and domesticate

animals Agriculture - the practice of growing, breeding, and caring for

plants and animals that are used for food, clothing, housing, transportation, and other purposes

This change is called the Agricultural Revolution. Allowed human populations to grow Changed the food we eat Habitats were destroyed - How?

The Industrial Revolution Mid 1700s Shift from energy sources, such as animal muscle and running

water to fossil fuels. Machinery reduced amount of land and human labor needed for

farming Agricultural and Industrial Revolution

Improved quality of life - How? Inventions - such as light bulb Increase sanitation, nutrition, and medical care vastly

Spaceship Earth Earth is a closed system - How? The only thing that enters is the sun, the only thing that leaves is

heat Problems?

Limited resources, produce waste faster than you can dispose of them

Population Growth

Increases in human population Faster production of food Modern medicine and sanitation

What are our Main Environmental Problems?

1. Resource Depletion Any natural material that is used by humans is called a natural

resource. Renewable Resource - A resource that can be replaced relatively

quickly by natural processes. Ex: sun energy, water, air Nonrenewable Resource - forms at a much slower rate than the

rate that it is consumed. Ex: minerals and fossil fuels 2. Pollution

An undesired change in air, water, or soil that adversely affects the health, survival, or activities of humans or other organisms

Two main types of pollutants: Biodegradable - broken down by natural processes Nondegradable - cannot be broken down by natural processes.

Ex: Plastic

What are our Main Environmental Problems?

3. Loss of Biodiversity Biodiversity - the number and variety of species that live in an

area. We depend on organisms for food, oxygen, and many other things. Is it important to preserve them?

2.2 The Environment and Society

"The Tragedy of the Commons" In 1968, ecologist Garrett Hardin published essay The difficulty in solving environmental problems is the conflict

between the short-term interests of individuals and the long-term welfare of society.

Animals grazing on commons Recycling

Economics and the Environment Supply and Demand - the greater the demand for a limited supply

of something, the more that thing is worth. Oil

Costs and Benefits - Balances the cost of the action against the benefits one expects from it. Desalination

Developed and Developing Countries

Population and Consumption Local Population Pressures - when population grows rapidly, there

may not be enough natural resources for everyone in the area to live a healthy, productive life

Consumption Trends - Developed countries have better quality of life - How? Developed nations use about 75% of the world's resources, even

though they make up only about 20% of the world's population Ecological Footprint - shows the productive area of Earth needed to

support one person in a particular country

A Sustainable World Sustainability - the condition in which human needs are met in such

a way that the human population can survive indefinitely Bald eagle - DDT