Ecosystem: a particular location whose interacting components include living (biotic) and non living (abiotic) components

Environmental Science study of ecosystems (ecology)

Environmentalism social movement that seeks to protect the environment

What is a sustainable system?

one that survives over some specified time that attains its full expected life span

a sustainable society manages it’s economy and population size without exceeding the planet’s ability to absorb environmental insults, replenish its resources and sustain life

Treeless volcanic island2200 miles off the coast of Chili

Moai -Stone Statues that line the perimeter of the island (250) 13 ft high and 14 tons.

Easter Island Story First inhabitants arrived at Easter Island

as early as 318AD. Most believe they were Polynesian, however, some think they arrived from South America.

Between 1400-1600, population was around 9,000.

In 1772, the first European visitors arrived on Easter Island. It was deserted! Barren!

There were signs of deforestation, soil depletion and erosion.

Most archeologist believe the natives cleared the trees for crop land. Planted crops stripped nutrients from the

soil. Clear signs of cannibalism.

LIVING OFF EARTH’S CAPITAL

Do Not eat the goose that lays the golden egg If you have one million in the bank at 10%

interest, you earn $100,000 year. If you spend just $110,000 per year you will be bankrupt in 18 years

Natural cycles will provide for us if we do not destroy our natural capitalDon’t

Eat me

Linear growth vs.exponential growth

linear growth: quantity increases by a fixed amount. EX. 1,2,3,4

Exponential growth: quantity increases by a fixed % of the whole in a given time. EX: 2,4,8,16,32

Fig. 1-2 p. 4Fig. 1-2 p. 4Fig. 1-2 p. 4Fig. 1-2 p. 4

Population is growing exponentially at a worldwide rate of 1.2%. In developing countries it is 1.7%. In developed countries it is .1%.

226,000 more people per day

Fig. 1.1, p. 2

World total

Developingcountries

Developedcountries

9

8

7

6

54

3

2

1

1950 2000

2050 2100

10

developed

developing

world

Fig. 1-3 p. 5Fig. 1-3 p. 5

Fig. 1.1, p. 2

16

15

14

13

12

11

Billio

ns o

f peop

le?

?

?

10

9

8

7

6

5

4

3

2

1

02-5 million

years8000 6000 4000 2000 2000 2100

Hunting and gathering

Black Death–the Plague

Time

Industrialrevolution

Agricultural revolution

B.C. A.D.

70 doubling

% growth rate time in years

70 51.8 years

World Population Growth Rate

1.35 %

An increase in the capacity to provide goods and services for people’s final use

economic growth is measured by an increase in GNP. GNP: gross national product: $ value of goods and

services produced by a country’s businesses within and outside the country

GDP: gross domestic product: $ value of goods and services produced within the country

GWP: gross world product: total $ value of goods and services produced in the world

The problem with GNP is the higher the GNP the more resource depletion and environmental damage. GNP is not the best indicator of quality of life.

per capita GNP: individuals slice of the economic pie

countries are classified as either developing or developed based on their per capita GNP and their level of industrialization developed countries:

U.S., Canada, Japan, Australia, New Zealand, and all of Europe. per capita GNP

greater than $10,000

generate 75% of pollution

use 88% of resources

have 85% of wealth

make up 20% of population

80% of population some are middle income $1,000 to

$10,000 per capita GNP like South Africa, Mexico, Brazil,

Malaysia some are low income with a per capita

GNP of less than 1,000 like India, Pakistan, China

95% of population growth will take place in developing countries

economic growth has allowed us to Live longer be healthier have more

comfort It has not allowed us

to stop

environmental problems

Wipe out poverty

encourages sustainable forms of economic growth that meets the basic needs of the current generations of humans without preventing future generations and other species from meeting their basic needs

discourages environmentally harmful and unsustainable forms of economic growth

it requires that governments, businesses and individuals integrate environmental goals into their decision making process

The Wealth Gap

the gap between per capita GNP or the rich and poor has greatly widened since 1980.

20% high income, 25% moderate income, 30% low income $2-3 / day, 25% very low income of less than $1.00/day.

1 in 5 is hungry, malnourished, lacks access to clean water, decent housing and health care.

Globalization is the broad process of global, social, economic and environmental change that leads to an increasingly integrated world.

A few indicators of globalization: global economy grew from 6.7 trillion to $42 trillion

since 1950

anything that we get from the environment to meet our needs and desires

perpetual resource: something that is continually renewed like solar energy

renewable: On a human time scale something that can be renewed fairly rapidly (Within decades)

biodiversity: variety of life forms that can survive a variety of conditions Genetic diversity species diversity ecological diversity provides free recycling, purification,

resources and pest control

renewable resources can be depleted SUSTAINABLE YIELD: highest rate at which a

renewable resource can be used without reducing its available supply

Tragedy of The Commons by “Garrett Hardin”: Overuse of common property resources, which are owned by no one but available to everyone free of charge. For example clean air, oceans, fish, Antarctica. This leads to exploitation then no one can use the resource. “ If I don’t use this resource then someone else will, the little bit I pollute is not enough to matter”

Fig. 1.11, p. 11

Resources

Perpetual Nonrenewable

Renewable

Freshair

Freshwater

Fertilesoil

Plants andanimals

(biodiversity)

Directsolar

energy

Winds, tides,

flowing water

Fossilfuels

Metallic minerals

Non- metallic

minerals

(iron, copper,

aluminum)

(clay, sand,

phosphates)

- deforestation water logging

or salinization of soil

deforestation pollution reduction in

biodiversity groundwater

depletion Wetlands

destruction

energy resources like coal, gas, uranium which are burned and lost

metallic mineral resources that can recycled

Non-metallic mineral resources that are difficult to recycle

Any addition to air, water, soil, or food that threatens the health, survival, or activities of humans or other animals. It can be natural or from humans

Two types of pollutant sources: point source: where pollutants come from a single

identifiable source, like a drainpipe or a smokestack. Non-point source: pollutants that come from dispersed

sources. Examples are runoff from fertilizers and pesticides or oil from cars.

Two approaches to dealing with pollution: pollution prevention pollution clean-up

rapid population growth rapid and wasteful use of resources with little

emphasis on pollution prevention degradation of life support systems poverty failure of economic and political systems to have

market prices that include environmental costs Our urge to dominate and manage nature for our

use with far too little knowledge of how nature works

Population x Affluence x Technology = Environmental Impact

Air Pollution• Global climate

change• Stratospheric ozone

depletion• Urban air pollution• Acid deposition• Outdoor pollutants• Indoor pollutants• Noise

Biodiversity Depletion

• Habitat destruction• Habitat degradation• Extinction

Water Pollution• Sediment• Nutrient

overload• Toxic chemicals• Infectious

agents• Oxygen

depletion• Pesticides• Oil spills• Excess heat

Waste Production

• Solid waste• Hazardous

waste

Food Supply Problems

• Overgrazing• Farmland loss

and degradation• Wetlands loss

and degradation• Overfishing• Coastal pollution• Soil erosion• Soil salinization• Soil waterlogging• Water shortages• Groundwater

depletion• Loss of biodiversity• Poor nutrition

MajorEnvironmental

Problems

Fig. 1.13, p. 14

United States

The Netherlands

India

CountryPer Captia Ecological Footprint(Hectares of land per person)

10.9

5.9

1.0

Fig. 1.10a, p. 11

CountryTotal Ecological Footprint

(Hectares)

United States

The Netherlands

India

3 billion hectares

94 million hectares

1 billion hectares

Fig. 1.10b, p. 11

Developing Countries

Population (P)Consumptionper person

(affluence, A)

Technological impact perunit of consumption (T)

Environmentalimpact of population (I)

Developed Countries

X

XX

XX

X =

=

=

Fig. 1.15, p. 15

Who should we believe? The precautionary principle Try not to be overwhelmed by the

environmental bad news because there is a lot of good environmental news.

“Never doubt that a small group of thoughtful, committed citizens cannot change the world. Indeed, it is the only thing that ever has”

Margaret Mead

The Invention that changed everything: The plow

Birth rates rose faster than death rates and population increased

People cleared increasingly larger plots of land and destroyed more natural habitat

People began accumulating material goods

Began in England in the mid 1700s Began when England used up all of its forests

and substituted coal for wood Shift from renewable to n on-renewable This lead to growth in mechanization and

factory towns Fossil fuel powered farm equipment lead to

an increased agricultural yield which lead to more people

Reduced infant mortality Raised life expectancy which lead to

more people Better health Birth control Education Affordable goods income

Cultural shift to new technologies such as TV, computers an internet

Hard to know what the impacts will be

Help us understand more about the Earth and how systems work

Allow us to respond to problems faster Use technology to monitor changes in the

Earth More sophisticated technology to model

complex systems Technology to reduce pollution and use

materials more effectively

Cause confusion, distraction, and a sense of hopelessness because of information overload

Increase environmental degradation and homogenization of world cultures

We are developing new technologies before we can evaluate their impact

1870-1900: environmental concern grows because of yellow fever, typhoid fever, cholera, garbage, air pollution, unsafe factories, contaminated water

1891 Forest Reserve Act: established the responsibilty of the federal government to protec public lands

1892: John Muir formed the Sierra club

Fig. 2.6, p. 31

Theodore Roosevelt was president He persuaded congress to give the president the

power to designate public land as wildlife refuges Roosevelt Established the bureau of reclamation He tripled the size of forest reserves 1905: Congress created the US Forest service to

manage and protect forest reserves. Gifford Pinchot was the first chief

1912: US National Park System was created by Congress

The passenger pigeon became extinct

Fig. 2.7, p. 31

Fig. 2.4, p. 30

Preservationists Believed humans

should protect nature, not conquer it

John Muir

Wise Use Believed resources

should be used wisely to enhance the nation’s economic growth

Gifford Pinchot Theodore Roosevelt

Both groups opposed delivering public lands into the hands of a few for profit

Both would be disappointed by what has happened over the years

The 1930s was the great depression and Franklin Roosevelt was president

Aldo Leopold became the leading professional in charge of wildlife management. Set up management plans for the Grand Canyon. Others followed his design

Low cost purchase of large tracts of land from cash poor landowners

Started Civilian Conservation Corp Built large dams to get cheap water to CA Enacted the Soil Conservation Act of 1935 that

was for combating the problem of soil erosion

CCC

Hoover Dam

Rachel Carson published Silent Spring, which documented how DDT was killing wildlife. The beginning of the environmental Era.

1964 Wilderness Act allowed the government to protect large tracts of public land as part of the National Wilderness System

1965-1970 science of ecology was created to understand earth

Cuyahoga River caught fire and burned for eight days

Massive air pollution in New York leaves 300 dead

Lake Erie beaches closed due to pollution

Santa Barbara coastline heavily polluted by leaking offshore oil rigs.

Foam in rivers from pollution

April 20th first Earth Day 1970 Richard Nixon created EPA (the

Environmental Protection Agency 1973 OPEC oil embargo 1974 CFCs found to be creating ozone

hole 1978 Love Canal 1979 Three Mile Island

The Wise Use movement was formed which was an industrial coalition aimed at destroying all the environmental laws

 * Goal of Science – creation of a new idea, principle, or model that connects and explains facts and leads to usable predictions about what is likely to happen in nature.

Scientific Method – Observe > Hypothesize > Argue > Test > Hypothesize > Argue > Test 

Scientific Theory – an idea or principle, or model that ties together and explains multiple facts that previously appeared not to be related and is supported by a great deal of evidence. (natural selection) 

Scientific or Natural Law – a description of what happens in nature time after time in the same way without known exception. (second law of thermodynamics)

  Steps 1. Pose a question2. Gather info (knowns)3. What new info/data needs to be gathered?4. Develop a hypothesis that explains data

and predicts new facts. Could there be other explanations?

5. Develop an experiment that can be done to test the hypothesis so it can become a scientific theory.

 

  1. Set up two groups 

a. Experimental group – chosen variable is changed in some way.

b. Control group – chosen variable is not changed.

This type of experiment is designed so that all conditions are the same except for the single variable in the experimental group. This is to be sure that the variable is the only factor that could possibly cause any observed change.

 

 2. Set up two groups 

a.   Experimental group – one group of patients is given a new drug.b.   Control Group – similar group of patients is given a placebo (sugar pill).

  This is called a double blind experiment because

neither the patient or the doctor is aware of who is receiving the drug or the placebo. This is done to avoid biased results.

  Multivariable Analysis – Many of the questions

investigated by environmental scientists involve a huge number of interacting variables (synergism). In multivariable analyses mathematical models run on high-speed computers are used to analyze the interaction of many variables.

 

1)      Disprove2)      Establish that a model, theory or law has an extremely high probability of being true.

Nothing can every be proven. Everything we know is just theory. Science is dynamic and changing.

 

  Frontier Science –

“breakthroughs” these are preliminary results that are often controversial because they have not yet been widely tested and accepted.

  Consensus Science -

consist of data, theories and laws that are widely accepted within the scientific community because they have been tested and retested or because observations of nature support them.

 

 1. Validity of Data – Difficulty of

Accurate Measurement (soil erosion, species extinction, forest loss)

 2. Multiple Variables - not enough

info, difficult to analyze data  

  Positive Feedback Loop – reinforces itself, a change in a

system, which causes the system to make another change in the same direction (vicious circle). Positive feedback systems destabilize a system. (Easter Island)

  Negative Feedback Loop - a change in a system which

results in a change in the opposite direction. Negative feedback loops lead to dynamic equilibrium and homeostasis within a system. (Body Temp)

  

Fig. 3.4, p. 51

Rate of metabolicchemical reactions

Heat inputfrom sun andmetabolism Heat loss

from aircooling skin

Heat in body

Positive feedback loop

Bloodtemperature inhypothalamus

Excess temperatureperceived by brain

Sweat productionby skin

Negative feedback loop

Synergistic Interaction - two or more processes interact so that the combined effect is greater that the sum of the two parts.

  Environmental

Scientists attempt to identify both harmful and beneficial synergisms so that we can:

 1. counter harmful ones2. promote beneficial

ones