Introduction to Environmental Science

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 components 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 ScienceEnvironmental Science is a

broad, interdisciplinary field

ES includes many fields of study, including the natural sciences and the social sciences

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

How do we upset the natural balance?We use resourcesWe produce waste

Definition of Environmental Science

(3) how to deal with environmental problems

To reduce or eliminate our unbalancing effect:Decision makingProblem solving

Why study Environmental Science?

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

Can you name them?

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???

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!)

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

1880

193019601974198719992015*

Yr. each billion was reached

* projected

Scale of Environmental ProblemsEnvironmental 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

Affluenza - unsustainable addiction to overconsumption and materialism exhibited in the lifestyles of affluent consumers in the United States and other developed countries

“Spaceship Earth”Earth - a closed system,

meaning materials do not enter or leave, only energy does

Damage that occurs stays in the system

(Figure 2, p. 536)

Ecological FootprintThis is one way to measure our impact on the environment globally.What is an ecological footprint?

• the environmental impact of a person or population• amount of biologically productive land + water needed for raw materials and to dispose/recycle waste

Overshoot: humans have surpassed the Earth’s capacity

10 Major Problems Facing Earth’s Environment (from Collapse by Jared Diamond)

1. Destruction of natural habitat

2. Loss of biodiversity3. Soil damage and

erosion4. Use of fossil fuels as

our main energy source5. Overuse of freshwater

resources

10 Major Problems Facing Earth’s Environment6. Release of toxic materials7. Introduction of “alien” species8. Release of harmful gases into atmosphere9. Human population growth10. 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.

http://www.bing.com/videos/search?q=easter+island&view=detail&mid=1040FBF74FAFE3D5A6581040FBF74FAFE3D5A658&first=0

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

The Good NewsJared 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.”

SummaryWhat’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