CHAPTER. An Introduction to Environmental Science

Transcription

1 CHAPTER 1 An Introduction to Environmental Science

2 Lesson 1.1 Our Island, Earth LIKE ALL SPECIES ON EARTH, HUMANS RELY ON A HEALTHY, FUNCTIONING PLANET FOR AIR, WATER, FOOD, AND SHELTER.

3 Lesson 1.1 Our Island, Earth What Is Environmental Science? National Marine Fisheries Service scientists studying whether commercial boats are harming endangered killer whales The study of our planet s natural systems and how humans and the environment affect one another The environment includes all living and nonliving things with which organisms interact. Understanding the interactions between humans and the environment is the first step to solving environmental problems.

4 Lesson 1.1 Our Island, Earth Environmental Science vs. Environmentalism Environmental Science: Objective, unbiased pursuit of knowledge about the workings of the environment and our interactions with it Environmentalism: Social movement dedicated to protecting the natural world Environmentalists protesting the use of nuclear power

5 Lesson 1.1 Our Island, Earth Natural Resources Found in nature Materials or energy Material Example: Water Energy Example: Sun Humans need natural resources to survive EVERYTHING we use comes from the Earth!

6 Where does it come from? oaluminum Can oplastic Bag obutter oleather Shoes oglass Bottle owooden Chair ocotton Jeans obread owool Sweater otire Can you name something that doesn t come from the Earth?

7 Where does it come from? oaluminum Can o Bauxite Mined oplastic Bag o Petroleum obutter o Cream and Milk from cow (grass) oleather Shoes o Cow Skin (grass) oglass Bottle o Silica/Sand owooden Chair o Timber from trees ocotton Jeans o Cotton from plant obread o Wheat, water, salt owool Sweater o Yarn from sheep hair (grass) otire o Rubber from tree

8 Renewable Resources Living resources that can replace or restock themselves, they can grow. Tends to have photosynthesis as the primary source of energy Solar Radiation can be considered renewable Can run out if not harvested sustainably

9 Non Renewable Resources Resources that exist in finite amounts on Earth Not renewed or replaced after they have been used or depleted Minerals and Fossil Fuels We can recycle many metals to the point that they can act like renewable resources.

10 Replenishable Resources Middle ground between renewable and nonrenewable Are replaceable, but only over a long period of time Length of time is the difference between Renewable and Replenishable Examples: Ground water and soil

11 Lesson 1.1 Our Island, Earth Natural Resources

12 Sustainability Living within the means of nature A society that supports itself by depleting natural resources is unsustainable Global Consumption 1961: use 49% 2001: use 121% Rises due to personal over consumption

13 Lesson 1.1 Our Island, Earth Human Population Growth Tremendous and rapid human population growth can be attributed to: The Agricultural Revolution: About 10,000 years ago; humans began living in villages, had longer life spans, and more surviving children. Industrial Revolution: Began in early 1700s; driven by fossil fuels and technological advances Spiked in 1900 Did You Know? The human population increases by about 200,000 people every day.

14 Lesson 1.1 Our Island, Earth Ecological Footprints Ecological footprints include land and water used to grow food at farms hundreds or thousands of miles away. The total amount of land and water required to: provide the raw materials an individual or population consumes dispose of or recycle the waste an individual or population consumes Did You Know? By one calculation, the ecological footprint of the average American is 3.5 times the global average.

15 Global Footprints

16 How Many Earths?

17 Lesson 1.1 Our Island, Earth Tragedy of the Commons Describes a situation in which resources, made available to everyone, are used unsustainably and eventually depleted Resource management, whether voluntary or mandated, can help avoid resource depletion. The commons refers to a public pastureland that was shared by villagers in 19th-century England.

18 Lesson 1.2 The Nature of Science THE WORD SCIENCE COMES FROM THE LATIN WORD SCIENTIA, MEANING KNOWLEDGE.

19 Lesson 1.2 The Nature of Science What Science Is and Is Not Science is an organized way of studying the natural world, and the knowledge gained from such studies. Science assumes that the natural world functions in accordance with rules that do not change. Science does not deal with the supernatural. Science relies on evidence from measurements and observations. Scientific ideas are supported, not proven, and accepted, not believed in.

20 Observations and Inferences Observations Sense words I feel the cold water in the pool. Inferences: Predictions (present or future) It s going to rain Based on prior knowledge, experiences, or observations Sarah is tired today.

21 Look at these two animal tracks. Make an OBSERVATION Make an INFERENCE

22 Now what do you think? Make an OBSERVATION Make an INFERENCE Have they changed their inferences?

23 Now what do you think? Make an OBSERVATION Make an INFERENCE

24 We will never be able to see what actually happened! Bottom line: In science, nothing can ever be proven! To find explanations about the world around us: We must make observations, run experiments, and draw conclusions to form educated guesses This process = scientific inquiry!

25 Tangrams Each piece represents current scientific data. With your partner: Make a square. Many of you got this

26 Adding on a new scientific discovery has been made X Many of you got this

27 How is this doing Science? Brainstorm with a partner

28 Some Possible Answers 1. Assume that the pieces fit together nature is a puzzle that we have not yet solved 2. Trial and error is an essential ingredient to science 3. New information may require the old theory to be modified or discarded 4. Our current information may be incomplete and therefore, our theories incorrect 5. Sometimes, we get lucky and find the right answer 6. Collaboration may be helpful 7. Once we arrive at the answer, it makes perfect, elegant sense.

29 Lesson 1.2 The Nature of Science The Process of Science Science involves asking questions, making observations, seeking evidence, sharing ideas, and analyzing results. Science is not linear the process loops back on itself and follows many different paths. Science is a dynamic, creative endeavor.

30 Scientific Way of Thinking Observation of natural phenomena often leads to questions In order to answer questions a scientist forms an hypothesis a proposed scientific explanation for observed phenomena Often takes the form of an If then statement Scientists design experiments to determine whether the hypothesis is correct

31 Controlled Experiments Controlled experiment: experiment in which only one variable is changed at a time Variable : factors in an experiment that can change The variable that is deliberately changed = independent variable (aka manipulated variable) The variable that is observed and that changes in response to the manipulated variable = dependent variable (aka responding variable)

32 Variables Independent Variable DependentVariable How much a plant grows compared to how much it is watered. Moisture content of soil compared to distance from the lake Heart rate compared to miles ran Temperature of a potato compared to time in the oven

33 Controlled Experiment Data is collected during the experiment Results of the experiment are recorded and analyzed The scientist uses experimental results to determine whether the hypothesis was supported or refuted. Scientific ideas are: supported not proven accepted not believed in

34 Example Observation: plants grow best when they are given adequate light, fertilizer, and water. Question: Will a plant grow faster if it is given more water Focus on only one variable at a time Hypothesis: If I give one plant more water than another similar plant then the plant that is given more water will grow faster.

35 Example (continued) The scientist may set up a controlled experiment where the manipulated variable is the amount of water the responding variable is the growth of the plant Data collection Analysis Conclusion

36 Lesson 1.3 The Community of Science SCIENTIFIC RESEARCH DOES NOT STOP WITH THE SCIENTIFIC METHOD. IN ORDER TO HAVE ANY IMPACT, SCIENTISTS MUST SHARE THEIR WORK AT CONFERENCES AND IN JOURNALS. THEY RECEIVE AND INCORPORATE FEEDBACK.

37 Lesson 1.3 The Community of Science Community Analysis and Feedback After completing their study, scientists: Present their work and get feedback from other researchers at conferences Write papers about their study Submit papers for publication in a journal Peer Review

38 Laws, Theories and Hypotheses

39 Laws Law: A logical relationship between two or more things that is based on a variety of facts and proven hypothesis. It is often a mathematical statement of how two or more quantities relate to each other. Examples: 1 st Law of Motion: an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Boyles Law: that the product of absolute pressure and volume is always constant. Conservation of Matter: Matter can neither be created or destroyed.

40 Theory Theory: well tested explanation that unifies a broad range of observations and hypotheses, and enables scientists to make accurate predictions about new situations. Examples: Cell Theory: All known living things are made up of cells. All cells come from cells. Cells are the basic unit of life.

41 Hypothesis v. Belief Hypothesis: A tentative statement such as if A happens then B must happen that can be tested by direct experiment or observation. A proven hypothesis can be expressed as a law or a theory. A disproven hypothesis can sometimes be re tested and found correct as measurements improve. Belief: A statement that is not scientifically provable in the same way as facts, laws, hypotheses or theories. CAN NOT BE TESTED

42 Lesson 1.3 The Community of Science Replication and Self Correction Hypotheses should be tested several times, in several ways, before they are accepted. Interpretations of data can change over time as knowledge accumulates. Sometimes reinterpretations can be drastic, but most of the time they are minor adjustments to an accepted idea. Did You Know? Scientists believed the sun and planets revolved around the Earth until Nicolaus Copernicus proved this was false in the 1500s. Science constantly refines and improves itself.

43 Lesson 1.3 The Community of Science Building on Environmental Science Addressing environmental problems involves more than just understanding the science. 40,000 buffalo hides, 1872 Ethics: Study of behavior (good and bad, right and wrong), moral principles, and values Culture: Ensemble of knowledge, beliefs, values, and learned ways of life shared by a group of people Worldview: Perception of the world and a person s place in it Ducks killed by an oil spill

44 Lesson 1.3 The Community of Science Environmental Ethics Environmental ethics is the application of ethical standards to the relationship between humans and the environment. Anthropocentrism: Humans and human welfare most important Biocentrism: All living things have value; some may be more important than others Ecocentrism: Well being of a species or community more important than that of an individual

45 Lesson 1.3 The Community of Science Environmental Justice The environmental justice movement: Recognizes that quality of life is connected to environmental quality Promotes fair and equitable treatment of all people regarding environmental policy and practice