Chapter 1 Introducing Environmental Science and Sustainability

Chapter 1Chapter 1Introducing Environmental Introducing Environmental Science and SustainabilityScience and Sustainability

Overview of Chapter 1Overview of Chapter 1

Human Impacts on The EnvironmentHuman Impacts on The Environment Population, Resources and the Population, Resources and the

EnvironmentEnvironment Environmental SustainabilityEnvironmental Sustainability Environmental ScienceEnvironmental Science Addressing Environmental ProblemsAddressing Environmental Problems

The Environment (Earth)The Environment (Earth)

Life has existed on earth for 3.8 billion Life has existed on earth for 3.8 billion years (oldest fossils are 3.4by [08/11])years (oldest fossils are 3.4by [08/11])

Earth well suited for lifeEarth well suited for life Water covers ¾ of planetWater covers ¾ of planet Habitable temperature, moderate sunlightHabitable temperature, moderate sunlight Atmosphere provides oxygen and carbon Atmosphere provides oxygen and carbon

dioxidedioxide Soil provides essential minerals for plantsSoil provides essential minerals for plants

But humans are altering the planet; not But humans are altering the planet; not always in positive waysalways in positive ways

Human Impact on the Human Impact on the EnvironmentEnvironment Satellite view of North America at Satellite view of North America at

nightnight

Human Impacts on Human Impacts on Environment— PopulationEnvironment— Population

Expected to add Expected to add several billion several billion more people in more people in 2121stst century century

EarthEarth’’s Human Population is over 6 billions Human Population is over 6 billion Growing exponentiallyGrowing exponentially

PopulationPopulation

1 in 4 people live in 1 in 4 people live in extreme poverty extreme poverty Cannot meet basic Cannot meet basic

need for food, clothing, need for food, clothing, shelter, healthshelter, health

Difficult to meet Difficult to meet population needs population needs without exploiting without exploiting earthearth’’s resourcess resources

Gap Between Rich and PoorGap Between Rich and Poor

Highly Developed Countries (HDC)Highly Developed Countries (HDC) Complex industrialized bases, low Complex industrialized bases, low

population growth, high per capita incomespopulation growth, high per capita incomes Ex: US, Canada, JapanEx: US, Canada, Japan

Less Developed Countries (LDC)Less Developed Countries (LDC) Low level of industrialization, very high Low level of industrialization, very high

fertility rate, high infant mortality rate, low fertility rate, high infant mortality rate, low per capita incomeper capita income

Ex: Bangladesh, Mali, EthiopiaEx: Bangladesh, Mali, Ethiopia

Types of Natural ResourcesTypes of Natural Resources

OverpopulationOverpopulation

People overpopulationPeople overpopulation Too many people in a given geographic Too many people in a given geographic

areaarea Problem in many developing nationsProblem in many developing nations

Consumption overpopulationConsumption overpopulation Each individual in a population consumes Each individual in a population consumes

too large a share of the resourcestoo large a share of the resources Problem in many highly developed nationsProblem in many highly developed nations

Ecological FootprintEcological Footprint

The average amount of land, water and ocean The average amount of land, water and ocean required to provide that person with all the required to provide that person with all the resources they consumeresources they consume

EarthEarth’’s Productive Land and s Productive Land and WaterWater

11.4 billion 11.4 billion hectareshectares

Amount Each Person is Allotted Amount Each Person is Allotted (divide Productive Land and (divide Productive Land and Water by Human Population)Water by Human Population)

1.8 1.8 hectareshectares

Current Global Ecological Current Global Ecological Footprint of each personFootprint of each person

2.7 2.7 hectareshectares

1 hectare equals about 2.5 1 hectare equals about 2.5 acresacres

Ecological Footprint Ecological Footprint ComparisonComparison

IPAT ModelIPAT Model

Measures 3 factors that affect Measures 3 factors that affect environmental impact (I)environmental impact (I)

I = P A TI = P A T

Environmental Environmental ImpactImpact

Number Number of peopleof people

Affluence per Affluence per personperson

Environmental Environmental effect of effect of

technologiestechnologies

Environmental Environmental SustainabilitySustainability

Environmental Environmental SustainabilitySustainability The ability to meet current human The ability to meet current human need for natural resources without need for natural resources without compromising the needs of future compromising the needs of future generationsgenerations

Requires Requires understanding:understanding: The effects of The effects of

our actions on our actions on the earththe earth

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

Tragedy of the Tragedy of the CommonsCommons

Garrett Hardin (1915-2003)Garrett Hardin (1915-2003) Solving Environmental Problems is Solving Environmental Problems is

result of struggle between:result of struggle between: Short term welfareShort term welfare Long term environmental stability and Long term environmental stability and

societal welfaresocietal welfare Common pool resourcesCommon pool resources Garrett used Common Pastureland in Garrett used Common Pastureland in

medieval Europe to illustrate the medieval Europe to illustrate the strugglestruggle

Sustainable DevelopmentSustainable Development

Economic development that meets the Economic development that meets the needs of the present generation without needs of the present generation without compromising future generationscompromising future generations

Environmental ScienceEnvironmental Science

An interdisciplinary study of human An interdisciplinary study of human relationship with other organisms relationship with other organisms and the earthand the earth BiologyBiology EcologyEcology GeographyGeography ChemistryChemistry GeologyGeology

PhysicsPhysics EconomicsEconomics SociologySociology DemographyDemography PoliticsPolitics

Earth As a SystemEarth As a System SystemSystem

A set of components that interact and function A set of components that interact and function as a wholeas a whole

Global Earth SystemsGlobal Earth Systems Climate, atmosphere, land, coastal zones, Climate, atmosphere, land, coastal zones,

oceanocean EcosystemEcosystem

A natural system consisting of a community of A natural system consisting of a community of organisms and its physical environmentorganisms and its physical environment

System approach to environmental scienceSystem approach to environmental science Helps explain how human activities affect Helps explain how human activities affect

global environmental parametersglobal environmental parameters

Earth SystemsEarth Systems

Most of earthMost of earth’’s systems are in s systems are in dynamic equilibrium or steady statedynamic equilibrium or steady state Rate of change in one direction equals Rate of change in one direction equals

that in the otherthat in the other FeedbackFeedback

Negative feedback- change triggers a Negative feedback- change triggers a response that counteracts the changed response that counteracts the changed conditioncondition

Positive feedback- change triggers a Positive feedback- change triggers a response that intensifies the changing response that intensifies the changing condition condition

FeedbackFeedback

Scientific MethodScientific Method

Controls and Variables in Controls and Variables in ExperimentExperiment

VariableVariable A factor that influences a processA factor that influences a process The variable may be altered in an The variable may be altered in an

experiment to see its effect on the outcomeexperiment to see its effect on the outcome ControlControl

The variable is not alteredThe variable is not altered Allows for comparison between the altered Allows for comparison between the altered

variable test and the unaltered variable testvariable test and the unaltered variable test

Inductive and Deductive Inductive and Deductive ReasoningReasoning Inductive ReasoningInductive Reasoning

Used to discover general principlesUsed to discover general principles Seeks a unifying explanation for all the Seeks a unifying explanation for all the

data availabledata available Ex:Ex:

FACTFACT: Gold is a metal heavier than water: Gold is a metal heavier than water FACTFACT: Iron is metal heavier than water: Iron is metal heavier than water FACTFACT: Silver is a metal heavier than water: Silver is a metal heavier than water CONCLUSIONCONCLUSION (based on inductive reasoning): (based on inductive reasoning):

All metals are heavier than waterAll metals are heavier than water Conclusions reached with inductive Conclusions reached with inductive

reasoning may change with new reasoning may change with new informationinformation

Inductive and Deductive Inductive and Deductive ReasoningReasoning Deductive ReasoningDeductive Reasoning

Proceeds from generalities to specificsProceeds from generalities to specifics Adds nothing new to knowledge, but Adds nothing new to knowledge, but

makes relationships among data more makes relationships among data more apparentapparent

Ex:Ex: GENERAL RULEGENERAL RULE: All birds have wings: All birds have wings SPECIFIC EXAMPLESPECIFIC EXAMPLE: Robins are birds: Robins are birds CONCLUSIONCONCLUSION (based on deductive (based on deductive

reasoning): All Robins have wingsreasoning): All Robins have wings

Five Stages to Five Stages to Addressing An Addressing An Environmental Environmental ProblemProblem Five steps are Five steps are

idealisticidealistic Case Study: Case Study:

Lake Lake WashingtonWashington

Assessing Environmental Assessing Environmental ProblemProblemCase Study: Lake WashingtonCase Study: Lake Washington Large, freshwater pondLarge, freshwater pond Suburban sprawl in 1940Suburban sprawl in 1940’’ss

10 new sewage treatment 10 new sewage treatment plants dumped effluent into plants dumped effluent into lakelake

Effect = excessive Effect = excessive cyanobacteria growth that cyanobacteria growth that killed off fish and aquatic killed off fish and aquatic lifelife

Scientific AssessmentScientific Assessment Aquatic wildlife assessment done in 1933 Aquatic wildlife assessment done in 1933

was compared to the 1950 assessmentwas compared to the 1950 assessment Hypothesized treated sewage was Hypothesized treated sewage was

introducing high nutrients causing growth of introducing high nutrients causing growth of cyanobacteriacyanobacteria

Risk AnalysisRisk Analysis After analyzing many choices, chose new After analyzing many choices, chose new

location (freshwater) and greater treatment location (freshwater) and greater treatment for sewage to decrease nutrients in effluentfor sewage to decrease nutrients in effluent

Assessing Environmental Assessing Environmental ProblemProblemCase Study: Lake WashingtonCase Study: Lake Washington

Public Education/InvolvementPublic Education/Involvement Educated public on why changes were Educated public on why changes were

necessarynecessary Political ActionPolitical Action

Difficult to organize sewage disposal in Difficult to organize sewage disposal in so many municipalitiesso many municipalities

Changes were not made until 1963!Changes were not made until 1963! EvaluationEvaluation

Cyanobacteria slowly decreased until Cyanobacteria slowly decreased until 1975 (gone)1975 (gone)


ResultsResults


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Chapter 1 Introducing Environmental Science and Sustainability