Chapter One: Introducing Environmental Science and

Sustainability

Environmental Science• Is the study of

human’s relationship with other organisms and the nonliving physical environment.

Our biggest problem….Human population

Human population reached 6 billion on October 12, 1999.

(It had been 3 billion in 1960)

• Poverty: The lack of basic needs such as adequate food, clothing, or shelter.

• Per capita income of less than 1 dollar per day. <$1

Almost ½ of the Earth’s people live in conditions of extreme poverty…

Lack of Sustainability

• Human population continues to grow despite Earth’s finite ability to support us.

Environmental sustainability

• The ability of the environment to function indefinitely without going into a decline from stresses imposed by human society.

• The goal is to meet present needs without endangering the welfare of future generations.

Reasons for a lack of sustainable use

• We are using renewable resources, such as water, faster than they can be replenished.

Reasons for a lack of sustainable use

• We are using nonrenewable resources as if there was an unlimited supply.

• Examples: Fossil fuels and their by-products Oil, Gasoline, Diesel, Kerosene ...

• We are polluting the environment with toxins as if the environment can continue to absorb them.

Lack of Sustainability

Pollution• Any alteration of air,

water, or soil that harms the health, survival, or activities of humans and other living organisms. Red colors indicate highest levels of CO (450 ppb). Blue colors indicate lowest levels of CO (50 ppb).

Air Pollution

Ex:• Smog pictured above

Los Angeles California

Global Warming- Rise in CO2 Levels

Soil and Water Pollution

• Pictures from the Exxon Valdez spill in 1989.

Light Pollution

Additional problems…Declining species diversity

and Habitat loss

• Declining bird and Amphibian populations throughout the world

Introduction of Exotic Species

• Species from foreign countries or areas compete with indigenous (native) species and are detrimental to them (and sometimes us).

• Can either be introduced intentionally or by accident.

• Examples: Gypsy moth caterpillars, Purple Loose-strife, zebra mussel.

Introduction of Exotic Species(Harmful, foreign species)

• Examples: Zebra Mussels, Purple loosestrife

More bad news…Commercial Extinction

• Populations of organisms become so low that it is no longer economically profitable to harvest.

• Example: Cod and the Georges Bank Fishery off the coast of New England.

What can we do?

• Stewardship- We have an obligation to act responsibly, and use resources in a sustainable manner.

• Not a “frontier attitude”

• Frontier Attitude: a desire to conquer and exploit nature as quickly as possible.

We need to re-assess our “ecological footprint.”

• Highly developed countries make up 20% of the earth’s population.

• They also consume more than half of it’s resources, and generate 75% of it’s wastes.

Resources

• Resources are a part of the natural environment that is used to promote the welfare of people or other species. Can be renewable or nonrenewable.

• Examples: H2O, air, soil, forests, minerals, & wildlife.

Resources

• Conservation: the careful management of natural resources.

• Examples: Phoenicians (3,000 Years ago) terraced farmland, Native Americans using entirety of slaughtered animals, Greeks used crop rotation.

The IPAT Model

I = P x A x T I= Environmental impact P = # People A = Affluence/person (i.e. Consumption) T = Environmental effects (Resources used and

wastes generated)

Tragedy of the Commons

(Garrett Hardin)

•Misuse of “commons” leads to private ownership and gov’t control.

•Now we have “global commons”•Stewardship is a must for all of us!

Scientific Method:

Controls, Variables, and Hypotheses

1.Control Group

(normal group for comparison to see the extent of the change)

2.Variable Group contains the factor to be tested (variable)

3. Hypotheses should be testable!

Scientific Principles

• Theories have withstood repeated testing and are associated with a certain level of confidence.

• Scientific Law: the term for a principle that is judged to be of great basic importance.

Inductive Reasoning

• Discovering general principles by the careful examination of specific cases.

• (From specific to general)

Inductive reasoningFact: Au is heavier than H2O.Fact: Fe is a metal that is heavier than H2O.Fact: Ag is a metal that is heavier than H2O.Fact: Li has ½ the density of H2O.We induce that most metals are heavier than water. Inductive reasoning produces new knowledge but is prone to error.

Deductive Reasoning:

• Makes relationships among data more apparent by proceeding from the general to the specific.

Deductive reasoning General rule: All birds have wings and can fly.

Therefore…Since Robins are birds…All robins have wings and can fly.

We deduce information directly from information given.

What can we induce from this?

We could induce that all chickens, eagles, and penguins have wings, and can fly.

We would be wrong!

Typical ExperimentA researcher concludes that

songbird populations decline in areas with high cowbird populations.

Inductive or deductive?

Typical ExperimentA researcher concludes that

songbird populations decline in areas with high cowbird populations.

(Inductive)

Typical ExperimentThis researcher would use

deductive reasoning to form a hypothesis.

Example: I feel that areas (general) without cowbirds (specific) will have more songbirds.

Experiment1. Collecting data from areas

without Cowbirds would be an example of a control test.

Scientific Assessment

• Scientific Assessment: the gathering of information.

• A model is created, which is a formal statement that describes a situation, and hopefully leads to a solution.

Risk Analysis:

• The results from the scientific assessment are used to analyze the potential effects of intervention.

• (What will happen if a course of action is taken?)

Risk Assessment:

• Quantifying the risks involved in a particular action so that they can be compared & contrasted with other risks.

Out of 10,000 people that smoke 1 pack of cigarettes a day, 3 or 4 will develop cancer. What are the risks associated with a particular action?

Risk Assessment:

Risk Management:

• Risks are evaluated with relevant political, social, & economic considerations to determine whether a particular risk should be reduced or eliminated. This evaluation includes the development and implementation of laws to regulate hazardous substances.

Public Education:

• Potential environmental problems are presented to the public along with available alternatives for action with probable cost and results of each choice.

• The National Environmental Policy Act of 1969 (NEPA) requires environmental impact statements for federal projects.

Political Action:

• Elected officials select a course of action and implement it.

• (Either based on scientific evidence, economic or social factors).

Follow-Through and Evaluation

• Results of actions taken are monitored to be assessed (are they working?) and to judge and improve the initial evaluation and modeling of the problem.

Ecological Risk Assessments:

• EPA has guidelines for estimating probable effects of human activities in ecosystems.

• Stressors: These are human induced changes that tax the environment.

• Cost-Benefit Analysis: the estimated cost is compared to determine how much expense society will incur to derive an environmental benefit.

The Lake Washington Case (Eutrophication, cyanobacteria, sewage)

1. Scientific assessment (model)2. Risk Analysis3. Public Education4. Political Action5. Follow through