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Chapter 1 Introducing Environmental Science and Stability.

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Presentation on theme: "Chapter 1 Introducing Environmental Science and Stability."— Presentation transcript:

1 Chapter 1 Introducing Environmental Science and Stability

2 Overview of Chapter 1 o Human Impacts on The Environment o Population, Resources and the Environment o Environmental Sustainability o Environmental Science o Assessing Environmental Problems

3 The Environment (Earth) o Life has existed on earth for 3.8 billion years o Earth well suited for life Water covers ¾ of planet Water covers ¾ of planet Habitable temperature Habitable temperature Moderate sunlight Moderate sunlight Atmosphere provides oxygen and carbon dioxide Atmosphere provides oxygen and carbon dioxide Soil provides essential minerals for plants Soil provides essential minerals for plants o But humans are altering the planet; not always in positive ways

4 Human Impacts on Environment- Population o Earths Human Population is over 6 billion Growing exponentially Growing exponentially o Expected to add several billion more people in 21 st century o Increase will adversely affect living conditions in many areas of the world o popclock popclock

5 Population o Globally, 1 in 4 people lives in extreme poverty Cannot meet basic need for food, clothing, shelter, health Cannot meet basic need for food, clothing, shelter, health o Difficult to meet population needs without exploiting earths resources

6 Gap Between Rich and Poor o Highly Developed Countries (HDC) Complex industrialized bases, low population growth, high per capita incomes Complex industrialized bases, low population growth, high per capita incomes Ex: US, Canada, Japan Ex: US, Canada, Japan o Less Developed Countries (LDC) Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income Ex: Bangladesh, Mali, Ethiopia Ex: Bangladesh, Mali, Ethiopia

7 Types of Natural Resources

8 Overpopulation o People overpopulation Too many people in a given geographic area Too many people in a given geographic area Problem in many developing nations Problem in many developing nations o Consumption overpopulation Each individual in a population consumes too large a share of the resources Each individual in a population consumes too large a share of the resources Problem in many highly developed nations Problem in many highly developed nations

9 Ecological Footprint o The average amount of land, water and ocean required to provide that person with all the resources they consume Earths Productive Land and Water 11.4 billion hectares Amount Each Person is Allotted (divide Productive Land and Water by Human Population) 1.9 hectares Current Global Ecological Footprint of each person 2.3 hectares

10 Ecological Footprint Comparison

11 IPAT Model o Measures 3 factors that affect environmental impact (I) I = P A T Environmental Impact Number of people Affluence per person Environmental effect of technologies

12 Environmental Sustainability o The ability to meet current human need for natural resources without compromising the needs of future generations o Requires understanding: The effects of our actions on the earth The effects of our actions on the earth That earths resources are not infinite That earths resources are not infinite

13 Tragedy of the Commons o Garrett Hardin ( ) o Solving Environmental Problems is result of struggle between: Short term welfare Short term welfare Long term environmental stability and societal welfare Long term environmental stability and societal welfare o Garrett used Common Pastureland in medieval Europe to illustrate the struggle

14 Sustainable Development o Economic development that meets the needs of the present generation without compromising future generations

15 Environmental Science o An interdisciplinary study of human relationship with other organisms and the earth Biology Biology Ecology Ecology Geography Geography Chemistry Chemistry Geology Geology Physics Physics Economics Economics Sociology Sociology Demography Demography politics politics

16 Earth As a System o System A set of components that interact and function as a whole A set of components that interact and function as a whole o Global Earth Systems Climate, atmosphere, land, coastal zones, ocean Climate, atmosphere, land, coastal zones, ocean o Ecosystem A natural system consisting of a community of organisms and its physical environment A natural system consisting of a community of organisms and its physical environment o System approach to environmental science Helps us understand how human activities effect global environmental parameters Helps us understand how human activities effect global environmental parameters

17 Earth Systems o Most of earths systems are in dynamic equilibrium or steady state Rate of change in one direction equals that in the other Rate of change in one direction equals that in the other o Feedback Change in 1 part of system leads to change in another Change in 1 part of system leads to change in another Negative feedback- change triggers a response that counteracts the changed condition Negative feedback- change triggers a response that counteracts the changed condition Positive feedback- change triggers a response that intensifies the changing condition Positive feedback- change triggers a response that intensifies the changing condition

18 Scientific Method

19 Controls and Variables in Experiment o Variable A factor that influences a process A factor that influences a process The variable may be altered in an experiment to see its effect on the outcome The variable may be altered in an experiment to see its effect on the outcome o Control The variable is not altered The variable is not altered Allows for comparison between the altered variable test and the unaltered variable test Allows for comparison between the altered variable test and the unaltered variable test

20 Inductive and Deductive Reasoning o Inductive Reasoning Used to discover general principles Used to discover general principles Seeks a unifying explanation for all the data available Seeks a unifying explanation for all the data available What does this information have in common? What does this information have in common? Ex: Ex: FACT: Gold is a metal heavier than water FACT: Gold is a metal heavier than water FACT: Iron is metal heavier than water FACT: Iron is metal heavier than water FACT: Silver is a metal heavier than water FACT: Silver is a metal heavier than water CONCLUSION (based on inductive reasoning): All metals are heavier than water CONCLUSION (based on inductive reasoning): All metals are heavier than water Conclusions reached with inductive reasoning may change with new information Conclusions reached with inductive reasoning may change with new information

21 Inductive and Deductive Reasoning o Deductive Reasoning Proceeds from generalities to specifics Proceeds from generalities to specifics Adds nothing new to knowledge, but makes relationships among data more apparent Adds nothing new to knowledge, but makes relationships among data more apparent Ex: Ex: GENERAL RULE: All birds have wings GENERAL RULE: All birds have wings SPECIFIC EXAMPLE: Robins are birds SPECIFIC EXAMPLE: Robins are birds CONCLUSION (based on deductive reasoning): All Robins have wings CONCLUSION (based on deductive reasoning): All Robins have wings

22 Five Stages to Addressing An Environmental Problem o Five steps are idealistic Real life is rarely so neat Real life is rarely so neat o Following Slides are Case Study Using the Five Stages

23 Assessing Environmental Problem Case Study: Lake Washington o Large, freshwater pond o Suburban sprawl in 1940s 10 new sewage treatment plants dumped effluent into lake 10 new sewage treatment plants dumped effluent into lake o Effect = excessive cyanobacteria growth that killed off fish and aquatic life

24 Assessing Environmental Problem Case Study: Lake Washington o Scientific Assessment Aquatic wildlife assessment done in 1933 was compared to the 1950 assessment Aquatic wildlife assessment done in 1933 was compared to the 1950 assessment Hypothesized treated sewage was introducing high nutrients causing growth of cyanobacteria Hypothesized treated sewage was introducing high nutrients causing growth of cyanobacteria o Risk Analysis After analyzing many choices, chose new location (freshwater) and greater treatment for sewage to decrease nutrients in effluent After analyzing many choices, chose new location (freshwater) and greater treatment for sewage to decrease nutrients in effluent

25 o Public Education/Involvement Educated public on why changes were necessary Educated public on why changes were necessary o Political Action Difficult to organize sewage disposal in so many municipalities Difficult to organize sewage disposal in so many municipalities Changes were not made until 1963! Changes were not made until 1963! o Evaluation Cyanobacteria slowly decreased until 1975 (gone) Cyanobacteria slowly decreased until 1975 (gone) Assessing Environmental Problem Case Study: Lake Washington

26 o Results! Assessing Environmental Problem Case Study: Lake Washington


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