Sean O’Brien AP Environmental Science Period 2 Mr. G. Cusimano 21 August 2009 Chapter 1 – Introducing Environmental Science and Sustainability (pg. 1) What Is Environmental Science? An interdisciplinary study of how humanity affects the relationships among other organisms and the nonliving physical environment. The branch of science concerned with the relations between organisms and their environment. The study of how we and other species interact with one another and with the nonliving environment (matter and energy). A physical and social science that integrates knowledge from a wide range of disciplines. A study of how the parts of nature and human societies operate and interact. Environmental science encompasses many complex and interconnected problems involving human numbers, Earth’s natural resources, and environmental pollution. Pollution can be viewed as any alteration of air, water, and soil that harms the health, survival, or activities of humans and other living organisms. Environmental science is an interdisciplinary because it uses and combines information from many disciplines: o Physics, chemistry, geology, and biology. o Geography, economics, and sociology. o Cultural anthropology and natural resources management.
Transcript
Sean O’Brien
AP Environmental Science
Period 2
Mr. G. Cusimano
21 August 2009
Chapter 1 – Introducing Environmental Science and Sustainability (pg. 1)
What Is Environmental Science?
An interdisciplinary study of how humanity affects the relationships among other organisms and
the nonliving physical environment.
The branch of science concerned with the relations between organisms and their environment.
The study of how we and other species interact with one another and with the nonliving
environment (matter and energy).
A physical and social science that integrates knowledge from a wide range of disciplines.
A study of how the parts of nature and human societies operate and interact.
Environmental science encompasses many complex and interconnected problems involving
human numbers, Earth’s natural resources, and environmental pollution.
Pollution can be viewed as any alteration of air, water, and soil that harms the health, survival, or
activities of humans and other living organisms.
Environmental science is an interdisciplinary because it uses and combines information from
many disciplines:
o Physics, chemistry, geology, and biology.
o Geography, economics, and sociology.
o Cultural anthropology and natural resources management.
o Agriculture.
o Law, politics, and ethics.
Why is the Environmental Science Important?
Because of the impact of the increase numbers of humans.
Because of the increase amount of consumption.
Because of the challenges and complexity of the problems we are creating.
One of the most important concepts currently used in environmental science is Environmental
sustainability.
o It can be defined as the ability to meet humanity’s current need without compromising
future generations to meet their needs.
o It also implies that the environment should function indefinitely without going into a
decline from the stresses imposed by human society on natural systems.
o Based in part on the following ideas:
We must consider the effects of our actions on the well being of the natural
environment.
Earth’s resources are not present in infinite supply and we must live within those
limits.
We must understand all the costs to the environment of the products we consume.
We must each share the responsibility for environmental sustainability.
Human Impacts on the Environment (pg. 2)
Experts believe human society is not operating to sustain the environment because:
o We use non-renewable resources as if they were present in unlimited supplies.
o We use renewable resources faster than they can be renewed naturally.
o We are polluting the environment with toxins as if the capacity of the environment to
absorb them is limitless.
o The number of humans continues to grow despite the Earth’s finite ability to feed and
sustain us and absorb our wastes.
The central problem of environmental science:
o Human population growth.
o The relationship between population growth and
the use of natural resources that cause
environmental degradation.
The increasing human population is placing
unsustainable stresses on the environment.
It is hoped that the world population will stabilize by
the end of the century at about 8 to 11 billion.
Population, Resources, and the Environment (pg.5)
Types of Resources:
o Renewable:
Solar energy.
Fertile soil.
Clean air.
Fresh water.
Biological diversity.
o Non-renewable:
Metallic minerals (gold, tin).
Nonmetallic minerals (salt, phosphates, stone).
Fossil fuels (coal, oil, natural gas).
Earth’s ability to support is unknown.
o Major challenge: feeding increased population without destroying biological habitats.
o Another important factor is managing level of consumption of resources.
o Three decisions:
Environmentally sound, economically viable, and socially equitable.
People overpopulation.
o Too many people in a given geographic area.
o Problem in many developing nations.
Consumption overpopulation.
o Each individual in a population consumes too large a share of the resources.
o Problem in many highly developed nations.
Modeling population, consumption, and environmental impact using IPAT where:
o I = environmental impact.
o P = number of people.
o A = affluence per person, which is a measure of the consumption or amount of resources
used per person.
o T = the environmental effects (resources needed and wastes produced) of the
technologies used to obtain and consume the resources.
General Equation: I = P × A × T
Shows the mathematical relationship between environmental impact and the driving forces
behind them.
The IPAT equation is valuable because it helps identify what we do not know or understand about
consumption and its environmental impact.
Use with caution because we often do not understand all the environmental impacts of
technologies on environmental systems.
The Nature of Science (pg. 14)
Science as a process.
A body of knowledge or collection of facts about the natural world.
A dynamic process or a unique way to investigate the natural world.
Science attempts to reduce the complexity to general scientific laws for use in solving problems
and providing further insights into the natural world.
Scientists collect data by observation and experimentation.
Scientists communicate their work to others, allowing them to confirm the validity of results
through repeatability.
Scientific results are never expressed in terms of absolute certainty; there always is a degree of
uncertainty.
How do scientists solve problems?
o The scientific method.
1. Recognize a question or
unexplained occurrence in the
natural world. After a good problem
is recognized, one investigates
relevant scientific literature to
determine what is already known
about it.
2. Develop a hypothesis, or educated
guess, to explain the problem. A
good hypothesis makes a
prediction that can be tested and
possibly disproved. The same factual evidence is often used to formulate several
alternative hypotheses; each must be tested.
3. Design and perform an experiment to test the hypothesis. An experiment involves
collecting data by making careful observations and measurements.
4. Analyze and interpret the data to reach a conclusion. Does the evidence match the
prediction stated in the hypothesis?
5. Share new knowledge. Publishing articles in scientific journals or books and
presenting the information at meetings permits others to repeat the experiment or
design new experiments that either verify or refute the work.
Controls and Variables in Experimental Design (pg. 18)
o A variable is any factor that influences the process under study.
o The experiment is designed to test one particular variable with respect to all other
variables; therefore all other variables need to be kept constant.
To accomplish this, two parallel experiments are conducted.
One (1) with an experimental group and one (1) with a “control group.”
o Control is an identical sample that is treated exactly like each
experimental sample except that the independent variable is not
manipulated in the control group and the dependent variable is
manipulated.
Inductive and Deductive Reasoning
o Scientists use both.
o Inductive reasoning : discovering general principles by careful examination of specific
facts.
Data is organized into manageable categories and examined for common
features.
Common factors are then used to express a “unifying explanation” for the data.
Basis of modern experimental science.
Provides new insights and knowledge but is prone to error.
Conclusions may be true or false.
o Deductive reasoning : proceeds from general principles to specific facts.
Adds no new insights but verifies relationships between variables.
Hypotheses are tested by deductive reasoning.
Hypothesis specific results predicted.
Tested experimentation.
Addressing Environmental Problems (pg. 17)
To understand and solve environmental problems we need the experience and expertise of many
individuals whether they are scientists, politicians, or the general public.
Environmental science is a problem-solving endeavor that assumes the role of identifying
problems and suggesting and evaluating possible solutions.
Implementing possible or proposed solutions is almost always a matter of public policy.
Elements that contribute to analyzing and solving environmental problems:
o How we gather information about the natural world and how humans affect those
processes.
o How we interpret that information and how certain we are of our conclusions.
o The process of decision-making and balancing trade-offs.
o 5 components of solving environmental problems:
1. Scientific assessment.
2. Risk analysis.
3. Public education.
4. Political action.
5. Follow-through or evaluation.
5 Steps to Environmental Problem-Solving:
1. Scientific Assessment:
a. The gathering of information.
b. Perform experimentation and collect data.
c. Construct a model.
d. Use the model to understand our current condition
and to predict future course of events.
e. Employ questions that arise in applying the model
to further investigate the problem.
2. Risk Analysis:
a. Take results of a scientific investigation to analyze potential effects of intervention.
i. What could be expected to happen if a course of action is followed?
ii. What are the adverse effects of taking action?
3. Public Education:
a. Inform the public regarding scientific assessment and risk analysis.
b. Inform the public regarding alternative courses of action.
c. Inform the public regarding the possible costs of available alternatives and expected
outcomes.
4. Political Action:
a. Public officials, acting on behalf of the public, select a course of action and
implement it.
b. Usually there are differences of opinion regarding interpretation of data and best
courses of action.
c. Some Disagreements are based on economic and social factors and not scientific
evidence.
5. Evaluation/Follow Through:
a. Must monitor the results of any action taken.
b. Need to assess if the environmental problem is being addressed.
c. Need to re-evaluate the model to more accurately describe the environmental
problem and make predictions.
Ecological Footprint (pg. 7)
The average amount of land, water, and ocean required to provide that person with all the
resources they consume.
Earth’s Productive Land + Water 11.4 billion hectares
Amount Each Person is Alloted 1.9 billion hectares
Current Global Ecological Footprint of
each person
2.3 billion hectares
Average Ecological Footprint of America 9.6 billion hectares
Scientific Decision Making and Uncertainty: An Assessment of Risks
What is risk?
o The probability of harm occurring under certain circumstances.
Human-risk assessment.
Environmental-risk assessment.
Risk is inherent in human activities.
o Walking on stairs.
o Driving a car.
o Sky diving.
Calculate probability of risks as fractions.
o Certain not to occur; probability = 0.
o Certain to occur; probability = 1.
o Most risks fall between 0 and 1.
o Example:
Risk of developing cancer from smoking is 0.0036.
Means that each year, 36 people out of 10,000 will develop cancer.
o Uses statistical methods to quantify the risks involved with a particular course of action.
o At the completion of the risk assessment that results are evaluated with relevant
considerations for political, social, and economic considerations to determine whether the
risk should be reduced or eliminated.
Includes development and implementation of laws and regulations and is known
as “risk management.”
Help to eliminate the probability of a risk and enable us to manage these risks.
4 steps of risk assessment:
1. Hazard identification.
2. Dose-response assessment.
3. Exposure assessment.
4. Risk characterization.
Case in Point: Lake Washington
o Large fresh-water lake on eastern boundary of Seattle, WA.
o Suburban sprawl in 1940’s expanded eastward.
o 10 new sewage treatment plants dumped effluent into the lake between 1941 and 1954.
“Effluent” means “treated waste.”
o Effect = excessive cyanobacteria growth that killed off fish and aquatic life.
o Scientific Assessment
Aquatic wildlife assessment done in 1933 was compared to 1950 assessment.
Hypothesized treated sewage was introducing cyanobacteria into water.
