1. Ch 1 An Introduction to Environmental Science
Part 1: Foundations of Environmental Science
PowerPoint® Slides prepared by
Jay Withgott and Heidi Marcum
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

2. Major Themes of Environmental Science
Human population growth
An urbanizing world
Sustainability of our population and all of nature
People and nature
A global perspective
Science and values

3. Gaia Hypothesis The belief that Earth has it’s own lifecycle
Elephants kill trees
Volcano’s erupt
Lightning causes fires
Global warming and cooling happened before without humans
The actions of many groups of people at many locations affects the environment of the entire world. (CFC’s)
Gaia hypothesis
James Lovelock and Lynn Margulis
Life affects the environment at a global level

4. Environment: the total of our surroundings
All the things around us with which we interact:
Living things - biotic
Animals, plants, forests, fungi, etc.
Nonliving things – abiotic (Natural)
Continents, oceans, clouds, soil, rocks, wind
Our built environment (Man-made)
Buildings, human-created living centers, roads, transportation

5. Humans and the world around us
Humans change the environment, often in ways not fully understood. Ex. Pest Control, weed killers
We depend completely on the environment for survival
Increased wealth, health, mobility, leisure time
But, natural systems have been degraded
i.e., pollution, erosion and species extinction
Environmental changes threaten long-term health and survival
Environmental science is the study of:
How the natural world works
How the environment affects humans and vice versa
Ecology – The study of the environment

6. Natural resources: vital to human survival
Natural resources = substances and energy sources needed for survival
Renewable resources:
Perpetually available: sunlight, wind, wave energy
Renew themselves over short periods: timber, water, soil
These can be destroyed
Nonrenewable resources: can be depleted (May be renewable???)
Oil, coal, minerals (not in our lifetime)

7. Sustainability and Carrying Capacity
What is the maximum number of people the Earth can sustain?
Currently we are using resources unsustainably. (30%)
Faster than they can be replenished.
Carrying capacity = the maximum number of individuals of a species that can be sustained by an environment
w/o decreasing the capacity of the environment to sustain that same amount in the future

8. Sustainability
Sustainability refers to resources and their environment.
Sustainable resource harvest
Same quantity of that resource can be harvested each year for an unlimited amount of time. (Trees – Silviculture)
Sustainable ecosystem
An ecosystem from which we are harvesting a resource that is still able to maintain its essential functions/properties. (Forest)

9. Sustainable Global Economy
To achieve we must
Develop an effective population-control strategy.(Controversial… legal? Terra Nova)
Completely restructure our energy programs. (Big Oil??)
Institute economic planning that will encourage pop control and wise use of resources.
Implement social, legal, political and educational change.

10. Terra Nova Policy?

11. Moving Toward Sustainability
The new paradigm
Evolutionary rather than revolutionary.
Inclusive, not exclusive.
Proactive, not reactive.
Attracting, not attacking.
Assisting the disadvantage, not taking advantage.

12. Global human population growth
More than 7 billion humans
Why so many humans?
Agricultural revolution
Stable food supplies
Industrial revolution
Urbanized society powered by fossil fuels
Sanitation and medicines
More food

13. Thomas Malthus and human population
Population growth must be restricted, or it will outstrip food production
Starvation, war, disease
Predator-prey relationships
Neo-Malthusians
Population growth has disastrous effects
Paul and Anne Ehrlich, The Population Bomb (1968)

14. Garrett Hardin’s Tragedy of the Commons
Unregulated exploitation leads to resource depletion
Soil, air, water
Resource users are tempted to increase use until the resource is gone
Solution?
Private ownership?
Voluntary organization to enforce responsible use?
Governmental regulations?

15. The “ecological footprint”
The environmental impact of a person or population
Amount of biologically productive land + water
for raw materials and to dispose/recycle waste
Overshoot: humans have surpassed the Earth’s capacity
We are using 30% more of the planet’s resources than are available on a sustainable basis!

16. Population Graphs

17. Exponential growth

18. Logistic Graph / S-Curve

19. Overpopulation Birth Rate Mortality Rate Total Population
Population Density
Immigration
Emigration
Catastrophic Ecents

20. Rule of 70 AKA Doubling time Doubling time = 70/ Growth Rate (PGR)
PGR = Net Gain (NG)/ total population
NG = Birth Rate – Death Rate + immigration-emigration
Classic Example = 7% growth rate – double time = 10 years

21. Homework for Thursday Pick 2 countries
Find birth rate, death rate, total population
Find 2 other countries with a positive growth rate
Find 1 country with a negative growth rate
Find 10 megacities (populations of 8 million +)

22. Environmental science
… can help us avoid mistakes made by past civilizations. The lesson of Easter Island: people annihilated their culture by destroying their environment. Can we act more wisely to conserve our resources?

23. Easter Island Named from Dutch Sailors who landed on Easter Sunday

24. Definitions
Limiting factors - things that prevent a population from growing any larger.
Disease, food supply, natural factors, humans, predation, nutrients
Biotic Potential - An estimate of the maximum capacity of living things to survive and reproduce under optimal environmental conditions. Continues forever.

25. S-Curve - Labels
Exponential growth, transitional phase (lag time), Plateau phase, carrying capacity, maximum sustainable yield

26. Precautionary Principle
Rio Earth Summit on Sustainable Development
Defined PP – when there is a great threat of serious environmental damage we should not wait for scientific proof before taking precautionary steps to prevent potential harm.

27. Precautionary Principle
PP is a proactive, rather than a reactive, tool.
Adopted by the city of SF and the European Union

28. Placing a Value on the Environment
The value of the environment based on 8 justifications
Utilitarian
Ecological
Aesthetic
Recreational
-- Inspirational
Creative
Moral
Cultural

29. Placing a Value on the Environment
Utilitarian- the environment has value because it benefits individuals economically or is necessary for human survival.
Ecological- ecosystem is necessary for survival of some species of interest or that the system itself provides benefit.

30. Placing a Value on the Environment
Aesthetic- has to do with our appreciation of the beauty of nature.
Recreational- viewing organisms in a natural setting.
Inspirational- to benefit the inner self
Creative- aid to human creativity

31. Placing a Value on the Environment
Moral- the belief that various aspects of the environment have the right to exist and it is our obligation to allow them to continue.

32. End of lecture day 1

33. The nature of science Science: Science is essential
A systematic process for learning about the world and testing our understanding of it
A dynamic process of observation, testing, and discovery
The accumulated body of knowledge that results from this process
Science is essential
To sort fact from fiction
Develop solutions to the problems we face

34. Applications of science
Policy decisions and management practices
Technology
Energy-efficient methanol-powered fuel cell car from DaimlerChrysler
Restoration of forest ecosystems altered by human suppression of fire

35. The scientific method
A scientist makes an observation and asks questions of some phenomenon
The scientist formulates a hypothesis, a statement that attempts to explain the scientific question.
The hypothesis is used to generate predictions, which are specific statements that can be directly and unequivocally tested.
The test results either support or reject the hypothesis

36. The scientific process is part of a larger process
The scientific process includes peer review, publication, and debate
A consistently supported hypothesis becomes a theory, a well-tested and widely accepted explanation
With enough data, a paradigm shift – a change in the dominant view – can occur

37. Types of Data Data are recorded observations or items of information
Data fall into two categories
Qualitative, or descriptions rather than measurements
Quantitative, or recorded measurements, which are sometimes organized into tables and graphs
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

38. Induction in Discovery Science
Inductive reasoning draws conclusions through a limited set of observations
Repeat specific observations can lead to important generalizations
For example, “the sun always rises in the east”
Deductive reasoning draws conclusions from initial definitions and assumptions by means of logical reasoning (transitive property of equality)
Mr. Daly is a human
Humans are mortal
Mr. Daly is mortal
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

39. The Role of Hypotheses in Inquiry
A hypothesis is a tentative answer to a well-framed question (If-Then statement)
A scientific hypothesis leads to predictions that can be tested by observation or experimentation
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

40. A Closer Look at Hypotheses in Scientific Inquiry
A hypothesis must be testable and falsifiable
Hypothesis-based science often makes use of two or more alternative hypotheses
Failure to falsify a hypothesis does not prove that hypothesis
For example, you replace your flashlight bulb, and it now works; this supports the hypothesis that your bulb was burnt out, but does not prove it (perhaps the first bulb was inserted incorrectly)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

41. Designing Controlled Experiments
A controlled experiment compares an experimental group (the artificial kingsnakes) with a control group (the artificial brown snakes)
Ideally, only the variable of interest (the color pattern of the artificial snakes) differs between the control and experimental groups
A controlled experiment means that control groups are used to cancel the effects of unwanted variables
A controlled experiment does not mean that all unwanted variables are kept constant
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

42. Limitations of Science
In science, observations and experimental results must be repeatable
Science cannot support or falsify supernatural explanations, which are outside the bounds of science
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

43. Theories in Science In the context of science, a theory is:
Broader in scope than a hypothesis
General, and can lead to new testable hypotheses
Supported by a large body of evidence in comparison to a hypothesis
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

44. Model Building in Science
Models are representations of natural phenomena and can take the form of:
Diagrams
Three-dimensional objects
Computer programs
Mathematical equations
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

45. The Culture of Science
Most scientists work in teams, which often include graduate and undergraduate students
Good communication is important in order to share results through seminars, publications, and websites
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

46. Science, Technology, and Society
The goal of science is to understand natural phenomena
The goal of technology is to apply scientific knowledge for some specific purpose
Science and technology are interdependent
Biology is marked by “discoveries,” while technology is marked by “inventions”
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

47. The combination of science and technology has dramatic effects on society
For example, the discovery of DNA by James Watson and Francis Crick allowed for advances in DNA technology such as testing for hereditary diseases
Ethical issues can arise from new technology, but have as much to do with politics, economics, and cultural values as with science and technology
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

48. Population & consumption
Human population growth exacerbates all environmental problems
The growth rate has slowed, but we still add more than 200,000 people to the planet each day
Our consumption of resources has risen even faster than our population growth.
Life has become more pleasant for us so far
However, rising consumption amplifies the demands we make on our environment.

49. The Millennium Ecosystem Assessment
The most comprehensive scientific assessment of the condition of the world’s ecological systems
Major findings:
Humans have drastically altered ecosystems
These changes have contributed to human well-being and economic development, but at a cost
Environmental degradation could get much worse
Degradation can be reversed, but it requires work

50. Our energy choices will affect our future
The lives we live today are due to fossil fuels
Machines
Chemicals
Transportation
Products
Fossil fuels are a one-time bonanza; supplies will certainly decline
We have used up ½ of the world’s oil supplies; how will we handle this imminent fossil fuel shortage?

51. Sustainable solutions exist
We must develop solutions that protect both our quality of life and the environment
Organic agriculture
Technology
Reduces pollution
Biodiversity
Protect species
Waste disposal
Recycling
Alternative fuels

52. Are things getting better or worse?
Many people think environmental conditions are better
Cornucopians: Human ingenuity will solve any problem
Some think things are much worse in the world
Cassandras: predict doom and disaster
How can you decide who is correct?
Are the impacts limited to humans, or are other organisms or systems involved?
Are the proponents thinking in the long or short term?
Are they considering all costs and benefits?

53. Sustainability: a goal for the future
How can humans live within the planet’s means?
Humans cannot exist without functioning natural systems
Sustainability
Leaves future generations with a rich and full Earth
Conserves the Earth’s natural resources
Maintains fully functioning ecological systems
Sustainable development: the use of resources to satisfy current needs without compromising future availability of resources

54. Conclusion
Environmental science helps us understand our relationship with the environment and informs our attempts to solve and prevent problems.
Identifying a problem is the first step in solving it
Solving environmental problems can move us towards health, longevity, peace and prosperity
Environmental science can help us find balanced solutions to environmental problems

55. QUESTION: Review
Which of the following is correct about the term “environmentalism”?
It is very science-oriented
It is a social movement to protect the environment
It usually does not include advocacy for the environment
It involves scientists trying to solve environmental problems
Answer: b

56. QUESTION: Review
Adding various amounts of fertilizer to plants in a laboratory is a _____ type of experiment
Correlative
Natural
Manipulative
Rare
Answer: c

57. QUESTION: Review What is the definition of “sustainable development”?
Using resources to benefit future generations, even if it means lower availability now
Letting future generations figure out their own problems
Using resources to satisfy current needs without compromising future availability
Letting each country decide what is its best interest
Answer: c

58. QUESTION: Weighing the Issues
Which do you think is the best way to protect commonly owned resources (i.e., air, water, fisheries)?
Sell the resource to a private entity
Voluntary organizations to enforce responsible use
Governmental regulations
Do nothing and see what happens
Answer: any

59. QUESTION: Weighing the Issues
Do you think the rest of the world can have an ecological footprint as large as the footprint of the United States?
Yes, because we will find new technologies and resources
Yes, because the footprint of the United States is not really that large
Definitely not; the world does not have that many resources
It does not matter; it’s not that important
Answer: any

60. QUESTION: Interpreting Graphs and Data
According to this graph, what has happened to the population over the last 500 years?
a) It has grown exponentially
b) It has grown linearly
c) It has decreased
d) It has slowed down recently
Answer: a

61. QUESTION: Interpreting Graphs and Data
What happens if test results reject a hypothesis?
The scientist formulates a new hypothesis
It shows the test failed
The hypothesis was supported
The predictions may not have been correct
Answer: a