Ch 1 Intro

Our Island, Earth

An Introduction to
Environmental Science

Ch 1
pp. 3-23

http://www.cmt.com/videos/misc/536
045/when-the-coast-is-clear.jhtml

Ch 1 Objectives

• Define the term “environment”

• Describe natural resources (renewable and
non-renewable) and explain their
importance to humans

• Characterize the interdisciplinary nature
of ES

• Understand the scientific method

• Evaluate the concepts of sustainability and
sustainable development

Student Independent
Learning

The Nature of
Science

pp. 10 – 16

Goals of Environmental Science:

1. To develop solutions to environmental
problems

2. Use these solutions to improve the
sustainability of our world

ES is interdisciplinary because: It
requires knowledge of

Natural Science: AND Social Science:

- Ecology - Economics

- Earth science - Political science
- Chemistry - Demography
- Biology - Ethics
- Anthropology

How has ES improved our world?

GASOLINE: Leaded or Unleaded

• 1920’s: lead was added to gasoline to
improve engine performance

• 1973: high levels of lead in atmosphere
are toxic = lead begins to be phased out

• 1996: Clean Air Act prohibited the sale
of leaded gasoline for autos (in US)

– Results: dramatic reduction in atmospheric
lead

Atmospheric Lead in US
1980-2006

Complete phase out of
leaded gas in 1996

EPA Takes Final Step in Phaseout of
Leaded Gasoline

[EPA press release - January 29, 1996]

EPA Administrator Carol M. Browner today took
the last steps concluding a 25-year Agency
effort to phase out lead from gasoline.

"The elimination of lead from gas is one of the great
environmental achievements of all time," Browner said.
"Thousands of tons of lead have been removed from the
air, and blood levels of lead in our children are down 70
percent. This means that millions of children will be
spared the painful consequences of lead poisoning, such
as permanent nerve damage, anemia or mental
retardation." The actions taken today, although
procedural, mark the end of a quarter-of-a-century of
work to keep Americans safe from exposure to lead from
gas.

Change is often controversial!
The Story of DDT (pesticides)

• Prior to WW2: Insects plague the world!
• DDT (~1939) was a “miracle cure” against

tropical diseases and agr. pests

• Rachel Carson -Silent Spring (1962)

highlighted the effects of pesticides
(impact on wildlife and human health)
• Reduced use of DDT = return of bald eagle,
brown pelican, osprey…

– Worldwide ban of DDT for agricultural use under
Stockholm Convention (2004)

BUT
What about DDT and human health?

FYI Facts:

• 1993: N/S America combined used 1.1
million kg of DDT to spray house walls but
this was less than 6% of the DDT used in
the USA in 1968 (total DDT used was
approx. 19.5 million kg)

• Lesson: Domestic use of

DDT is TINY compared to

agricultural use.



Human Population Growth:

An Agent of Change

• Agricultural Revolution (10,000
years ago)

1. Nomadic lifestyle became sedentary
2. Domestication of livestock
3. Domestication of crops

• improved health = increase family size
• improved life expectancy

Ex. Zimbabwe 4.36 % per year!

(15.6 million people – DT 16 yrs)
LE = 57.5

Human Population Growth:

An Agent of Change

• Industrial Revolution (mid 1700s)

– Rural life dependent on animal power
changed to mechanized life
dependent on fossil fuels

• Improved sanitation (health)

• Increased agricultural production with
equipment, fertilizers and pesticides

• Has resulted in climate change

– Loss of permanent ice; loss of biodiversity
(coral reefs/rainforests…); economic/social
and political impacts

Population growth or Climate
Change?

Population Growth

Predicting its Impact

• Thomas Malthus (early 1800s)

– British economist – Increasing population =
increase in famine, war and death

– Social structures & laws are needed (ex.
controlling pop. growth) to avoid doomsday

• Paul Ehrlich (1960s)

– American biologist – Increasing pop. and

consumption were a “Population Bomb”
– Predicted famine and death resulting from

overpopulation

Population Growth

Predicting its Impact

• Garret Hardin (1968)

– Tragedy of the Commons: unregulated
resources will be exploited and
eventually depleted

– Regulation is needed through:

• private ownership
• voluntary cooperation
• government regulation

• Read the Essay

Ecological Footprint

Humanity uses 30% more resources than
are available on a sustainable basis!

• Measures an individual’s environmental
impact based on

– Land use
– Water use
– Waste produced

• Calculates how much
of the Earth’s surface is
needed to sustain your
lifestyle



Is Growth Sustainable?

The steep increase in human population
has amplified our impact on
environment

– 78 million people are added to the
human population each year!
(= +200,000 per day!)

Can we continue to CONSUME without
replenishing?

Growth has resulted in:

1. Increase in pollution and waste
2. Increase in destruction of habitat
3. Increase in impact on global

climate
4. Decrease in biodiversity
5. Increase in fossil fuel dependency
OTHER ideas?

Quality of human life is intimately
connected to environmental quality

Is Growth Sustainable?

Benefits of development are NOT equally
shared:

20 wealthiest nations have 40
times more wealth than the 20

poorest nations

To be sustainable, growth MUST

1. improve quality of life
2. protect the environment

Triple Bottom
Line

Sustainable Development

“… MUST use resources (both
renewable and nonrenewable) that
help to economically advance
society without compromising the
future availability of those
resources”

Sustainable solutions to
environmental problems must meet
social and economic goals