Chapter 1 Science 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