Lecture 1websites.rcc.edu/halama/files/2020/06/Biology-19-Lecture... · 2020-06-24 · 6/22/2020 1...

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© 2015 John Wiley & Sons, Inc. All rights reserved.

Website:

websites.rcc.edu/halama


Lecture 1

Why Environmental Science?

Humans and the Environment

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Lecture 11. What is Environmental Science?

2. Sustainability

3. Environment defined

4. Human Impacts on The Environment

5. Population, Resources, and Consumption

6. Addressing Environmental Problems (an

example)


What is Environmental Science?

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Environmental Science

• The interdisciplinary study of humanity’s relationship with

other organisms and the non-living physical environment.

• Interdisciplinary – biology, geography, chemistry, geology,

physics, economics, sociology, cultural anthropology,

agriculture, engineering, law, politics, and ethics.

• Encompasses many complex and interconnected

problems/issues.

• GOAL…Promote Sustainability!


Environmental Sustainability

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

• Try to avoid over consumption by wisely managing our resources.

• Requires understanding:– The effects of our actions on

the earth

– That earth’s resources are not infinite

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Environmental Scientists• Ecologists - try to establish general principles as to how the

natural world functions

• Use this knowledge to develop viable solutions to environmental

problems

• In association with…

– Economists

– Chemists

– Sociologists

– Etc.


Environmental Science

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Sustainability?


We are using nonrenewable resources such as fossil fuels as if

they were present in unlimited quantities…

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We are polluting the environment with toxins as if the capacity of the

environment to absorb them is limitless…


We are using renewable resources, such as freshwater and

forests, faster than they can be replenished naturally…

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Our numbers continue to grow despite Earth’s finite ability to feed and

sustain us and absorb our wastes…


Environment

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Environment

The surroundings or

conditions in which a

person, animal, or plant

lives or operates.


EnvironmentThe complex of physical, chemical, and biotic factors (such as

climate, soil, and living things) that act upon an organism or

an ecological community and ultimately determine its form

and survival.

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Human Impact on the Environment


The Environment (Earth)

• 4.5 billion years old.

• Earth well suited for life…

– Water over ¾ of planet

– Habitable temperature, moderate sunlight

– Atmosphere provides oxygen and carbon dioxide

– Soil with essential minerals for plants

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The Environment (Earth)

Life has existed on earth for ~ 3.8 billion yrs.


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Modern humans (Homo sapiens) appeared ~100,000 years ago in

Africa and quickly expanded to the rest of the world…

Human Impacts on Environment- Population

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• Middle Ages – approx. 500 million

• 1960 – 3 billion

• Now, human population is ~7.1 billion

• Growing almost exponentially

• Estimates of 8-11 billion by end of 21st century

• However, growth rate appears to be slowing



• We are the most significant agent of environmental change

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• The population change is not the same everywhere on the

planet….



• The consequences of this rapid increase in population change is

not felt the same everywhere on the planet….

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Population

• More than 1 in 4 people live in

extreme poverty

– Cannot meet basic need for food,

clothing, shelter, health

• Difficult to meet population

needs without exploiting earth’s

resources


Gap Between Rich and Poor

• Countries differentiated based on wealth…

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• Highly Developed Countries (HDC)

–Complex industrialized bases,

–Low population growth,

–High per capita incomes




– (19% population, 50% economic activity)

–Ten most “developed” countries:

10.Denmark,

9. Singapore,

8. Canada,

7. New Zealand,

6. Germany,

5. USA,

4. Netherlands,

3. Switzerland,

2. Australia,

1. Norway

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–U.S. 5% of the world population, consumes 25% of the world’s

resources.



• Less Developed Countries (LDC)

–Low level of industrialization (agriculture),

–Very high fertility rate

–High infant mortality rate

–Low per capita income

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• Less Developed Countries (LDC)

–This list contains 49 countries:

– 33 in Africa (all sub-Saharan)Others in southeast Asia and

a number of small island states in the Pacific.

10. South Sudan

9. Senegal

8. Afghanistan

7. Côte d’Ivoire

6. Malawi

5. Ethiopia

4. Guinea

3. Burkina Faso

2. Burundi

1. Niger


Gap Between Rich and Poor• Rising income disparity in many countries (Developing)

– Large gap between wealthy and poor citizens

• Differential access to electricity, cars, modern medicine

– Ex: China, India, Brazil, Mexico

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Two ways this disparity impacts the

environment…

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Population and Resource UseLess Developed Countries…

• Essential resources for individual survival are small

• People require very little to meet their basic needs

– BUT…Rapidly increasing population can quickly overwhelm or

deplete resources, especially locally


Population and Resource Use

• HDC - Resource consumption can far outweigh needs of

survival

– People require very little to meet their basic needs, but…

– Affluent nations use larger portions and can exhaust resources

globally

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Resources


Natural Resources

Something, such as a air, freshwater, a forest,

or a mineral deposit that is found in nature

and is necessary or useful to humans.

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Natural Resources


Consumption

–Human use of Natural Resources

–People in HDCs are big consumers, well beyond what is

needed for survival.

– 1 child born in the HDC has a greater impact on resources

than 12 born in a LDC.

–U.S….3% of the world population, consumes about 25% of

its resources.

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IPAT Model

• Measures 3 factors that affect environmental impact (I)

I = P A T

Environmental

Impact

Number of

people

Affluence per

person

Environmental

effect of

technologies


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Why environmental problem occur…

• Unsustainable Consumption

–Occurs when the level of demand on a country’s

resources damages or depletes the resource enough to

reduce the quality of life for future generations

1. Caused by overpopulation – situation in most developing

countries (LDC).

2. Caused by overconsumption – developed countries,

consume way more that needed for survival (HDC).


Ecological Footprint

• The average amount of land, water and ocean required to provide

that person with all the resources they consume

Earth’s Productive Land and Water 11.4 billion hectares

Amount Each Person is Allotted (divide Productive Land &

Water by Human Pop.)

1.8 hectares

Current Global Ecological Footprint of each person 2.7 hectares

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Ecological Footprint Comparison

Ecological footprints are not all equal:


Addressing Environmental Problems (an

example)

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Five Steps to Addressing An Environmental Problem

• Five steps represent

ideal approach

• Reality is untidy

• Often, public pushes

for a solution


Assessing Environmental Problem

Case Study: Lake Washington

• Large, deep freshwater lake

• Suburban sprawl in 1940’s

– 10 new sewage treatment plants

dumped treated effluent, high in

nutrients, into lake

• Effect = excessive growth of

cyanobacteria

– Bacterial decomposition of

cyanobacteria depleted O2

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• Scientific Assessment

– Scientists from University of Washington studied problem and

collected data

– Study informed Washington Pollution Control Commission (1955)

• Commission concluded that effluents added nutrients, particularly

phosphorus

• Nutrients caused growth of cyanobacteria

• Cyanobacteria decomposed by bacteria depleting O2

• Low O2 reduced fish and small invertebrates

– If pollution stopped, lake would recover




• Recovery Plan

– Many political hurdles in passing a plan

– Accepted bill was most ambitious and expensive pollution control

project in U.S. at the time

• Treated sewage was diverted into trunk sewer that ringed lake (starting in

1963)

• Eventually discharged into Puget Sound, where it would have less effect

• By 1975, lake was heathy and water was clear

• Today, work to reduce waste generation in view of greater population

around lake



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• Data shows recovery

plan working



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Lecture 1websites.rcc.edu/halama/files/2020/06/Biology-19-Lecture... · 2020-06-24 · 6/22/2020 1...

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