Ch. 1 - Science & the Environment

Transcription

1 Ch. 1 - Science & the Environment Environmental science the study of how humans interact with the environment; a major goal of environmental science to solve environmental problems What are some of the current major environmental problems we are facing? 1. Use of natural resources 2. Effect of human actions on the environment 1

2 Roots to know & love: Bio = life Zoo = animal Bot = plant Ology = study of Eco = earth Micro = small Geo = earth Paleo = ancient Hydro = water Anthro = people 2

3 Environmental science requires study in many different areas: 1. Biology = study of living organisms (zoology, botany, microbiology, ecology) ** Ecology = study of how living things interact with each other and with their nonliving environment (ecologist would study the effect of zebra mussels on Lake Erie while an environmental scientist would study how they were introduced by humans) 3

4 2. Earth Science = study of earth's nonliving components (geology, paleontology, climatology, hydrology) 4

5 3. Physics = study of matter and energy (engineering) 5

6 4. chemistry = study of chemicals and their interactions (biochemistry, geochemistry) 5. Social sciences = study of human populations (geography, anthropology) 6

7 A look at our history shows how the U.S. has changed as a result of human interaction: 1. Hunter-gatherers obtain food by collecting plants and hunting wild animals; migrate from place to place; would set fire to prairies to prevent tree growth - this made it easier to hunt bison; overhunting along with rapid climate changes led to disappearance of sloths, saber-toothed cats, giant bison, etc.; large bone piles found show were animals were driven into pits and killed 7

8 2. Agricultural revolution agriculture is practice of growing, breeding, and caring for plants & animals used for food, clothing, housing, etc. --> began about 10,000 years ago --> allowed for population growth because an area of farmed land can produce 500 times more food than if it was just hunted/gathered on --> selective breeding (plumpest berries, largest ears of corn, etc.) resulted in the type of plants changing over time --> resulted in much habitat destruction (slash & burn, erosion, flooding) 8

9 3. Industrial revolution dates to the middle 1700's; involved a shift from energy sources - animal and water powe to fossil fuel power --> greatly increased efficiency which led to more concentrated population centers which led to pollution and habitat loss --> many artificial substances were created - and we are dealing with the results of these today 9

10 Earth is essentially a closed system = everything basically remains here (sunlight is added and heat is removed but all else remains on/near earth) 1. Resources are finite 2. Waste remains on earth 10

11 Population growth = during the 1900's, worldwide population quadrupled; its predicted to double again in the 21st century. FYI: 1804 = Total population was 1 billion 1960 = Total population was 3 billion 1999 = Total population was 6 billion 2050 =????? 11

12 Increased population leads to our current environmental problems: Resource depletion natural resource = any natural material used by humans renewable resource = can be replaced relatively quickly by nature (water, wood, soil, air, sunlight) nonrenewable resource = forms at a slower rate than it is consumed (iron, aluminum, copper, salt, sand, clay, fossil fuels) 12

13 In 1968, Garrett Hardin published the Tragedy of the Commons sheep were allowed to graze on a common area, people needed to limit the grazing time so they wouldn't destroy the grazing area, everyone was afraid that others would get more so they all overgrazed, the area was destroyed and the sheep starved. Short-term interests vs. long-term welfare of society Concept of Commons video.asx 13

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15 We must take responsibility for our resources by planning, organizing, considering evidence, and proposing solutions. Economic considerations are critical 1. Supply/demand greater the demand for a limited supply of something, the more valuable it becomes (oil prices!!) 2. Costs/benefits balances the cost of an action against the benefits one expects from it (often depends on who is doing it industry vs. community for pollution controls) 3. Risk assessment how much risk is involved with an action (this depends on accurate information ex: nuclear power is less risky than riding a bike!) 15

16 Ecological footprint = the productive area of Earth needed to support one person in a particular country In the U.S., we need 30 acres per person whereas in India they need 3! 16

17 Environmental problems are very complex - the solution is never simple. We must be educated about both sides!! The key goal of environmental science is SUSTAINABILITY!! Sustainability = human needs are met in such a way that a human population can survive indefinitely 17

18 1.2 The Nature of Science Root word alert! Scire = to know (science is to know!) Experimental method: 1. Observation = using senses or measuring 2. Hypothesis = a testable explanation for an observation 3. Prediction = a logical statement about what will happen if hypothesis is correct 4. Experiment = procedure designed to test a hypothesis A good experiment has: a. Variable the factor being tested b. Experimental group this receives the experimental treatment c. Control group doesn't receive the experimental treatment independent variable- are the variable that the scientist manipulates dependent variable- variable that depends on the conditions set by the experiment example: A scientist could hypothesize that adding fertilize to a pond increase the production of algae. In order to test this he adds fertilizer to one pond and leaves another one alo In this experiment fertilizer input is the independent variab and the results, algae or no algae, is the dependent variable. 5. Collect Data - information gathered from experiment 6. Draw Conclusions - use data to answer prediction 7. Repeat experiment 8. Communicating results - share experimental results 18

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20 I think extra phosphate in Lake Erie is promoting Zebra mussel growth Observation: Lake Erie is getting full of zebra mussels. Hypothesis: High levels of phosphate are causing rapid Zebra mussel growth Prediction: If I put extra phosphate in a tank full of Zebra mussels, they will grow more rapidly than those in a tank without phosphate Experiment: Get two tanks. Give them equal light, food and water levels (control all other variables!). Put extra phosphate in 1 tank (the experimental group) and not the other (the control group). Data: Measure total mass of zebra mussels each week. Draw Conclusions: The experimental group's mass increased by 15% while the control groups mass only increased by 5%. Repeat experiment Communicate results: Share with other groups interested in zebra mussel populations. 20

21 You must be careful when using correlations as the basis for your predictions and hypothesis. For example, the increase in the incidence of polio always correlated with an increase in the consumption of soft drinks. Did soft drinks cause polio??? Polio is caused by a virus that appears when the weather warms up and thus, when more soft drinks are consumed. But soft drinks DO NOT cause polio. POLIO 21

22 Thinking like a scientist requires: 1. Curiosity 2. Skepticism 3. Openness to new ideas 4. Intellectual honesty 5. Imagination and creativity 22

23 1.3 The Community of Science The scientific community, through peer review and replication, helps to verify the accuracy of results and contributes to the establishment of scientific theories. Sound science is based on replication rather than a one time occurrence. Even when a hypothesis appears to explain observed phenomena, scientists need to always consider othe explanations. Generally, a hypothesis must be able to be tested over and over again with the same results before scientists are willing to accept it. 23

24 Hypotheses are explanations for a narrow set of occurrences. Theories are a broad explanation that apply to a wide range of situations and observations. A theory is a well tested set of observations and experimental findings. In everyday language when we say something is just a theory, we are suggesting it is an idea without much substance. Scientists mean the exact opposite when using the term. Scientists are extremely confident in accepted theories. 24

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26 Benefits and Outcomes Environmental ethics explores how environmental science interacts with, and is guided by, a society s morals and principles. Ethics is a branch of philosophy that involves the study of behavior : good and bad, right and wrong. The term ethics can also refer to 26

27 Worldview and culture can influence what a scientist chooses to study or where to look for inspiration. Environmental ethics= is the application of ethical standards to relationships between humans and their environment. Anthropocentrism= describes a human centered view of our relationship with the environment. An anthropocentrist place the highest value on humans and human welfare. Biocentrism= gives value to all living things. In this perspective, nonhuman life has ethical standing, so biocentris actions evaluates actions in terms of their overall effect on living things, both human and nonhuman. Ecocentrism= judges actions in terms of their benefit or harm to the integrity of whole ecological systems, which consist of both living and nonliving elements and the relationships among them. An ecocentrist would value the well-being of species, communities, and ecosystem over the well-being of a given individual. The environmental justice movement promotes the fair and equitable treatment of all people with respect to environmental policy and practice, regardless of their income, race or ethnicity. 27

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