Unit 1: Unit 1: APESAPES

Courtesy of Ann McClung

Revised by S. Purser 8-2010

Chapter 1Chapter 1

Environmental Problems, Their Causes, and Sustainability

IntroductionIntroduction

Environment External conditions that

affect living organisms

Ecology Study of relationships

between living organisms and their environment

Environmental Science Interdisciplinary study

that examines the role of humans on the earth

Many different groups of people are concerned about environment! See spotlight p. 3

Linear GrowthLinear Growth

Quantity increases by a constant amount per unit of time

Ex: 1,3,5,7,9, … When plotted on a

graph, growth of money yields a fairly straight line sloping upward

0

20

40

60

80

100

120

1960 1980 2000 2020

Exponential GrowthExponential Growth Quantity increases

by a fixed percentage - starts off slowly, then grows to enormous numbers

Result is a J-shaped curve

Humans are the only species growing this way today.

How does this impact our environmental resources?

0

500

1000

1500

2000

2500

3000

1970 1980 1990 2000 2010 2020

Population Growth

Rule of 70Rule of 70

How long does it take a population to double? Resource use Population size

Rule of 70 70 divided by the percentage growth rate

= doubling time in years Currently, the human population growth

rate (world wide) is 1.3%. In what year, do you predict the world population will have doubled?

Resources for LifeResources for Life

Capital = wealthSolar Capital

Energy from the sun (including wind, hydro & biomass)

Provides 99% of the energy used on earth

Earth Capital Planet’s air, water, soil, wildlife,

minerals, natural purification, recycling, pest control,… (natural resources)

SustainabilitySustainability The ability of a system to

survive and function over a defined period of time

This means living within one’s means - not depleting capital!

If you have $1,000,000 in your bank account… 10% interest Sustainable living requires

spending less than $100,000 per year

The same applies to earth’s natural capital!

Two Options for Survival in the Face of a Growing Population

1. Live sustainably by eliminating waste and discontinuing the depletion and degradation of resources.

2. Overcome these problems with ingenuity, economic growth, and technology.

Economic Growth - Economic Growth - Key TermsKey Terms

Economic Growth Increase in the capacity to provide goods

and services for people’s use Throughput of Matter and Energy

Resources used to produce goods and services through an economy – varies with location and products

High throughput = more consumption per person

Economic Growth - Economic Growth - Key TermsKey Terms

Gross National Product – GNP Measures economic growth in a country Market value in current dollars of all goods

and services produced within and outside of a country by the country’s businesses during one year

Gross Domestic Product – GDP Market value in current dollars of all goods

and services produced only within a country during one year

Economic Growth - Economic Growth - Key TermsKey Terms

More Developed Countries (MDC) Highly industrialized Average per capita GNP above $4000 Higher life expectancy

Less Developed Countries (LDC) Low to moderate industrialization Average per capita GNP below $4000 (Africa, Latin America, and parts of Asia)

Economic Growth - Economic Growth - Key TermsKey Terms

Development Change from a society that is largely rural,

agricultural, illiterate, poor and rapidly growing population

Globalization An more socially, economically, and

environmentally interconnected world.

Per Capita GNP GNP divided by the total population Shows one person’s slice of the economic pie

Wealth GapWealth Gap

The gap between the rich, middle-income and poor has widened

More than 1 billion people survive on less than one dollar per day

Poverty and Environmental degradation go hand in hand

Perpetual & Renewable Resources

Perpetual – renewed continuously (solar)

Renewable (on human scale)– can be replenished rapidly as long as it is used sustainably (forests, grasslands, wild animals, fresh water, fresh air, fertile soil)

Tragedy of the CommonsTragedy of the Commons

Common Property Resources Resources owned by none,

but available to all users free of charge

May result in depletion or degradation of the resource

Examples – ocean pollution, deforestation, abuse of national parks, grazelands

Solutions? Limit access, regulations, reduce population, convert public to private ownership

http://blog.nature.org/2009/10/sanjayan-tragedy-commons-ostrom-conservation-nature-conservanc/

Nonrenewable ResourcesNonrenewable Resources

Nonrenewable/Exhaustible Resources Exist in a fixed quantity in the earth’s crust and

can be used up – ex. Fossil fuels & minerals

Solutions:Reduce – ex: product with less packagingRefuse – don’t buy it at all!Recycling Collecting and reprocessing a resource into new

products Reuse Using a resource over and over in the same

form – example?

What is Your Ecological Footprint?It is YOUR impact on the environment The amount of biologically productive

land and water needed to supply renewable resources and absorb waste for each YOU!

Currently, each person’s ecological footprint is 20% greater than can be sustained indefinitely.

Result? polluted air and water, waste overload, poorer health, less biodiversity, etc.

We need four more planet Earths to meet the consumption levels of the U.S.

Take the quiz! Ecological Footprint

PollutionPollution

Any addition to air, water, soil, or food that threatens the health, survival, or activities of humans or other living organisms

May be added by human activity OR natural causes

Point Source PollutantsPoint Source Pollutants

From a single, identifiable source Smokestack of a

power plant Drainpipe of a

meat-packing plant

Exhaust pipe of an automobile

Non-point Source PollutantsNon-point Source Pollutants

Dispersed and often difficult to identify sources Runoff of fertilizers and pesticides Storm Drains (#1 source of oil spills in oceans)

Issues of Concern with PollutantsIssues of Concern with Pollutants

Chemical NatureHow active and

harmful it is to living organisms

ConcentrationAmount per unit

volume or weight of air, water, soil or body weight

PersistenceTime it stays in the

air, water, soil or body

Solutions: Prevent it!Solutions: Prevent it!

Input Pollution Control Slows or eliminates

the production of pollutants

often by switching to less harmful chemicals or processes

Solutions: Clean it up!Solutions: Clean it up!

Output Pollution Cleanup Involves cleaning up pollutants after

they have been released Most expensive and time consuming

Causes of Environmental Problems

Developing Countries increasing population poverty exploitation of resources for

survival Lack of education Disease/poor health careDeveloped countries High per capita resource use

& resulting pollution and environmental degradation

Technology pollution NOTE: affluence can also

lead to environmental improvements!

Major Environmental ProblemsMajor Environmental Problems Biodiversity Depletion Air Pollution Water Pollution Waste Production Food Supply Problems

See fig 1-9, p. 12

Model of Environmental ImpactModel of Environmental Impact

Population (P) x

Consumption per person (A) X

Technological impact per unit consumption (T) =

Environmental impact of population

P x A x T = ISee Fig 1-11, p. 13

Chapter 2 – Environmental History

Hunter-GatherersHunter-Gatherers

Had only three energy sources: Sunlight in captured

plants Fire Their own muscle

power Very little impact

on environment

Agricultural Revolution Agricultural Revolution Agricultural Revolution

Cultural shift that began in several regions of the world

Involved a gradual move from a lifestyle based on nomadic hunting

Agro-forestryPlanting a mixture of

food crops and tree crops

Agricultural Revolution Agricultural Revolution Slash-and-burn

Cutting down trees and other vegetation and then burning the underbrush to clear small patches of land

Subsistence Farming

Family grew only enough food to feed itself.

Environmental WorldviewsEnvironmental Worldviews

How people think the world works

What they think their role in the world should be

What they see as right and wrong environmental behavior (environmental ethics)

Planetary Management WorldviewPlanetary Management Worldview

Increasingly common during the past 50 years.

We are the planet’s most important species

We are in charge of the rest of nature

Planetary Management WorldviewPlanetary Management Worldview

There is always moreAll economic growth is

goodPotential for economic

growth is limitlessOur success depends on

how well we manage earth’s system for our benefit

                                                                                   

Earth-Wisdom WorldviewEarth-Wisdom WorldviewNature exists for all of the

earth’s species, not just for us

There is not always moreNot all forms of economic

growth is beneficial to the environment

Our success depends on learning to cooperate with one another and with the earth

Working with the EarthWorking with the Earth

Earth WisdomLearning as much as we

can about how the earth sustains itself

Adapt to ever-changing environmental conditions

Integrating such lessons from nature into the ways we think and act

Feedback LoopsFeedback Loops

A feedback loop occurs when an output of a system is fed back as an input

Two kinds of feedback loops

Positive Negative Positive or Negative?

Feedback LoopsFeedback Loops Positive loops are runaway cycles where

a change in a certain direction causes further change in the same direction Melting of permafrost will release methane

which will accelerate global warming Negative loops help to maintain stability

in a system Ex. Predator/Prey relationships help to

maintain balance in populations… OR… blood sugar/insulin

Synergy vs ChaosSynergy vs Chaos

Synergy occurs when two or more processes interact so the combined effect is greater than the sum of the separate effects

Chaos occurs in a system when there is no pattern and it never repeats itself Noise versus Music