Chapter 1 Introducing Environmental Science and Stability

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

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

Human Impacts on Environment- Population o Earth’s Human Population is over 7 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

Population o Globally, 1 in 5 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 earth’s resources

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

Types of Natural Resources

Overpopulation o People overpopulation Too many people in a given Too many people in a given geographic area geographic area Problem in many developing Problem in many developing nations 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

Ecological Footprint o The average amount of land, water and ocean required to provide that person with all the resources they consume Earth’s Productive Land and Water 11.4 billion hectares Amount Each Person is Allotted (divide Productive Land and Water by Human Population) 1.63 hectares Current Global Ecological Footprint of each person 2.3 hectares

Ecological Footprint Comparison

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

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 earth’s resources are not infinite That earth’s resources are not infinite

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

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

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

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

Earth Systems o Most of earth’s 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

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 The following slides illustrate a Case Study using the Five Stages

Assessing Environmental Problem Case Study: Lake Washington o Large, freshwater pond o Suburban sprawl in 1940’s 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

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

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

o Results! Assessing Environmental Problem Case Study: Lake Washington

Scientific Method

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

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 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

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