Introduction to Environmental Science

Ch 1 Science & The Environment

• 1 Understanding Our Environment

• 2 The Environment and Society

Ch 1 Science & Environment

• Section 1 Understanding our environment– I can define environmental science.– I can compare and contrast environmental

science and ecology– I can list the 5 major fields of study that

contribute to environmental science– I can describe the major effects of humans on

the environment throughout history

Section 1

– I can distinguish between renewable and

non-renewable resources– I can classify environmental problems into

three major categories

Introduction to Environmnetal Science

How do you define “environment”?

Introduction to Environmental Science

• Environment – – Everything around us, living and nonliving,

natural and man-made– Includes the relationships between these

parts of the environment

What is Environmental Science?

Definition of environmental science:

the interdisciplinary study of (1) how the earth works, (2) how we interact with the earth, and(3) how to deal with environmental

problems

Let’s break that down…

Definition of Environmental ScienceEnvironmentalSciene

is a broad, interdisciplinary , applied science involving 5 major

fields of study:• Biology • Earth science, • Chemistry, • Physics,• Social Sciences

Goals of Environmental Science

• Understand + solve environmental problems

• 2 Main areas:– How we use natural resources– How our actions affect the environment

• Example: How the nesting behavior of bees is influenced by human activities, such as landscaping.

• Can you give any other examples?

Definition of Environmental Science

(1) how the earth works

How do the four spheres of our planet function naturally to maintain a balance?

• atmosphere• biosphere• lithosphere• hydrosphere

Definition of Environmental Science

(2) how we interact with the earth (our impact on the environment)

How do we upset the natural balance?

How do we use resources?

How do we produce waste?

What do we do with out waste?

Definition of Environmental Science

(3) how to deal with environmental

problems

To reduce or eliminate our unbalancing effect:

Decision making

Problem solving

Why study Environmental Science?

Rapid changes in earth’s environment due to human activities can be traced to two “revolutions”:

• Life has existed on earth for 3.8 billion years

• Earth well suited for life– Water covers ¾ of planet– Habitable temperature– Moderate sunlight– Atmosphere provides oxygen and carbon

dioxide– Soil provides essential minerals for plants

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

POPULATION• Globally, 1 in 4 people lives

in extreme poverty – Cannot meet basic need for

food, clothing, shelter, health

• Difficult to meet population needs without exploiting earth’s resources

OVERPOPULATION

• People overpopulation– Too many people in a given geographic area– Problem in many developing nations

• Consumption overpopulation– Each individual in a population consumes too

large a share of the resources– Problem in many highly developed nations

Hunter-GatherersHumans and our ancestors

Hunter-Gatherers

• 60,000-12,000 years ago• Nomadic – followed plants & animals

(allowed nature to repair itself)• Lived in small groups-impact low• Life expectancy – 30-40 years• Experts on native plants• Low resourse use per person• Over-hunting: disappearance of species?

Hunter-Gatherers

Hunter - Gatherers• Collected plants, hunted, fished, and were

nomadic, moving with the seasons

• Pop growth slow due to high infant mortality and shorter life expectancy

• Small impact on the environment

• Altered distribution of plants and animals (extinction of large animals)

• Low resource use per person, migration, and lack of technology allowed environmental repair to occur

Discovery of Fire• Effect on vegetation widespread &

devastating (kept grasslands open)• Affected areas where original action not

intended (not all environments adapted to withstanding fire)

• Selective in its effect on species (some can handle fire better than others)

Domestication of plants

Agricultural Revolution

Gradual move from nomadic lifestyle of hunter-gatherers to the farming of domesticated animals and plants

Started about 10,000 years ago

Led to human population

explosion

Can you explain why???

Agricultural Revolution

• 12,000-10,000 years ago (end of last ice age)

• Domestication of:– Plants by women (artificial selection of best

grains) (figs, rice, barley, wheat)– Animals (wolves 3000BC, goats & sheep,

horses)

Longer life span (better food)

• Deliberate destruction of natural vegetation to cultivate elected crops

• Forced people to settle in specific places• Caused development of towns – led to

changes in land use and population growth (500xs as many people as hunting)

• Created problems for waste disposal• People began to accumulate material

good

• Development of harmful chemicals & pesticides

• Survival of native plants & animals, once vital to survival, became less important

• Growth of more food, enabling populations to expand

• Conflict between society more common as ownership of land & water rights became

crucial economic issues

• Encouraged use of domesticated animals in work (ploughing, transport)

• Large forested areas cleared for farms• Created soil erosion, orgrazing, and other

environmental problems (collapse of civilization in Tigris-Euphrates river basin through salt contamination in overworked soil)

– People settled into communities, cultivated plants & domesticated animals

– Provided food for longer, healthier living, but increased environmental degradation

– Slash-and-burn cultivation developed in tropical regions (cleared small patches of forests, burned underbrush & left ashes to fertilize soil)

– Sustainable cultivation (shifting/ rotational) meant little impact on land

slash & burn

Archaeological record indicates that plant & animal domestication arose independently in at least 7, and possibly more, separate locales

Centers of domestication Dates (years b.p.)Near East/"fertile crescent“ 11,000Northern China 9,000Southern China (?) 8,000Central Mexico 5,750Peruvian Andes 5,250Papua New Guinea 6-9,000West Africa 4,500Eastern No. America 4,000

Urbanization

• Large-scale disruption of forests• Improvements in human welfare &

expansion of human populations beyond limits set by pre-agriculture patterns of life

• Growth in transportation and polllution problems

European Colonization

• Large scale environmental degradation under colonial exploitation of resources in former colonies in Africa, Latin America, India

• No regard for environmental consequences

• Devalued natural resources in colonial states

• The Frontier Era (1600s)

–European settlers considered land a frontier to conquer and settle

–Resources were thought to be

inexhaustible and the land was

viewed as hostile, dangerous,

and needing to be conquered

PROBLEMS

• 1. Dependency on few plants--Agriculture made human communities dependent on relatively few plants--the main crops which they grew--rather than on the many different kinds of plants which hunter-gatherers use.

• 2. Greater vulnerability to weather—

• Complete dependency on harvest times--To survive, agriculturalists have to gather all their food for the year at one or two or three harvest times, rather than gathering year round.

• Nothing can be allowed to interrupt the harvest.

• Agricultural communities became more time- conscious.

• store the produce of their fields for the rest of the year, protect it from moisture, vermin, and thieves

• learn to dole out supplies in measured quantities so the community can survive

• have seed for next year's planting.• • These conditions created a new kind of life style.

4. Need for intense physical labor

specialization becomes possible

5. wealth acquires meaning

6.Humans had never before lived in large groups or in densely packed spaces. They had to learn how to do so successfully (perhaps we are still learning how).

• problem of polluting one's living space

• need to develop elaborate cultural means of disposing of their dead, or of their food wastes or excrement, or of the wastes of their livestock. • Mobile hunter-gatherer groups must necessarily limit the number of children they have to care for at any given time; large families of many children mean more hands to help in the fields.

• infectious disease, a problem closely related to population growth and to the difficulty of maintaining a clean, healthy living space.

Environmental problems began to occur:

Habitat destruction

Beginning of soil erosion and overgrazing of areas

Pollution of natural resources

Industrial Revolution

Industrial Revolution

Development of machines to do manual/animal labor

Led to use of non-renewable energy sources (fossil fuels) that disrupt the balance of our ecosystems (started in mid-1700’s – recent!)

Industrial Revolution

• Industrial-Medical Revolution (about 275 ya; 1700s)

Began in England in the 1700s; came to the U.S. in 1800s

Shift from reliance on renewable resources (wood) to dependence on machines & nonrenewable fossil fuels

Centralized factories began to mass-produce goods

Higher standard of living coupled with greater environmental degradation

• Advancements led to the reduction in number of farmers needed to produce sufficient food more people moving into towns

• Use of fossil fuels in factory towns led to air pollution from ash and soot

• Working conditions were often dangerous

• Because of aliments and working conditions advancements in medicine occurred

Industrial Revolution• Large scale use of fossil fuels & mineral

resources that pollute air, soil & environment

• Development of new forms of transportation - boosted international trade and made available goods & services in distant locations

• Created shift from dependence on renewable fuels to dependence on non-renewable fuels

• Began in England in mid 1700’s• Spread to US in 1800’s• People lived longer & healthier• Environmental degradation increased• Factory towns sprang up, people left farms• Factory towns grew polluted, noisy,

hazardous• Coal smoke filled cities

• Reduced amount of land & labor needed for farming

• Improved quality of life: electricity, sanitation, nutrition, medical care improved, improved communication through telephone & computer

• Shift from natural products & medicines to man-made (plastics, synthetics)

The Human Population Over Time:Locate agricultural and industrial revolutions….

1880

1930

1960

1974

1987

1999

2015*

Yr. each billion was reached

* projected

Scale of Environmental Problems

Environmental problems are typically categorized by the affected population.

• Global problems, like global warming and the hole in the ozone layer affect the entire world population.

• Local problems, such as deforestation or pollution, can occur on a local scale

“Spaceship Earth”

Earth - a closed system, meaning materials do not enter or leave

Limit to resources

Damage that occurs stays in the system

Energy enters from sun, heat leaves (open system)

10 Major Problems Facing Earth’s Environment

(from Collapse by Jared Diamond)1. Destruction of

natural habitat

2. Loss of biodiversity

3. Soil damage and erosion

4. Use of fossil fuels as our main energy source

5. Overuse of freshwater resources

10 Major Problems Facing Earth’s Environment

6. Release of toxic materials

7. Introduction of “alien” species

8. Release of harmful gases into atmosphere

9. Human population growth

10. Increasing standard of living

A tragic metaphor for “Spaceship Earth” ?

Easter Island is a relatively small, isolated Pacific island on which there are hundreds of large stone sculptures, indicating that a complex society once lived there

Reference on Easter Island, Collapse: How Societies Choose to Fail or Succeed, by Jared Diamond

A tragic metaphor for “Spaceship Earth” ?

When European explorers arrived in the 1700’s they found a mostly barren landscape, with no trees over 10 feet tall, yet there were hundreds of toppled statues all over the island.

The few people living on the island had no horses or oxen, were using grass to build fires and lived a primitive lifestyle.

The mystery: How did the Easter Islanders build and erect the statues, why did they do it and what happened to the civilization that accomplished this?

A tragic metaphor for “Spaceship Earth” ?

Evidence has been pieced together to provide the following explanation:

The island was settled by Polynesians from other islands around 400 CE.

At that time there were trees, including palms, on the island as shown by pollen studies. There is evidence that land and sea birds were abundant.

The human population grew as high as 30,000 as the islanders harvested dolphins and fish for food using wooden canoes. They also ate native island birds and rats. Farms were started to provide more food.

A tragic metaphor for “Spaceship Earth” ?

Like other Polynesian cultures, society was divided into chiefs and commoners, which were established into clans.

On Easter Island, there was collaboration between the clans, but also competition that resulted in building the large stone heads using rock from an island quarry and moving them into place on their territory. One theory is that this process required many workers to move them by pulling them along wooden tracks, possibly on a wooden sled. All of this required a huge expenditure of resources to support the structures and feeding the workers.

A tragic metaphor for “Spaceship Earth” ?

Eventually, the island was completely deforested, leading to local extinction of many species on which the islanders depended, as well as the loss of the raw materials to sustain their standard of living. Deforestation also led to soil erosion and a decrease in crop yield from farms. Climate change may have contributed to deforestation.

A tragic metaphor for “Spaceship Earth” ?

By 1680, civil war replaced the organized clans. People survived as best they could, raising more domesticated chickens for food. The statues that had once been erected as a sign of superiority between clans were then toppled over by rival clans, and remained as evidence of the societal collapse when the Europeans arrived.

A tragic metaphor for “Spaceship Earth” ?

Is this a small scale model of what could happen to our planet?

Similarities: overexploitation of resources in a fragile, closed system, with no where to escape, no place to get more resources

Environmental Problems

1. Resource depletion– Renewable vs nonrenewable

2. Pollution– Biodegradable vs nonbiodegradable

3. Loss of biodiversity– Habitat destruction– extinction

The Good News

Jared Diamond writes in Collapse, “While we do face big risks, the most serious

ones are not ones beyond our control, …. Because we are the cause of our environmental problems, we are the ones in control of them, and we can choose or not choose to stop causing them and start solving them.”

Summary

What’s the situation?• We depend completely on the environment for survival • We are experiencing increased wealth, health, mobility,

leisure time• Humans change the environment, often in ways not fully

understood – unintended consequences• Natural systems have been degraded i.e., pollution,

erosion and species extinction• Environmental changes threaten long-term health and

survival

• “We are the most dangerous species of life on the planet, and every other species, even the earth itself, have cause to fear our power to exterminate. But we are also the only species which, when it chooses to do so, will go to great effort to save what it might destroy”

Wallace Stegner

Environmental Sustainability

• The ability to meet current human need for natural resources without compromising the needs of future generations

• Requires understanding:– The effects of our actions on the earth– That earth’s resources are not infinite

Sustainable DevelopmentEconomic development that meets the needs of the present generation without compromising future generations