Transcript Environmental Science

Environmental Science
Unit 1 Environmental Issues, Their
Causes, & Sustainability
(STE Chapter 1, pp. 1-16)
Where are we going?
1. Living more sustainably
2. Population growth, economic growth, and
sustainable development
3. Resources
4. Pollution
5. Problems: causes and connections
6. Is our present course sustainable?
1.1 Living more sustainably
environment - everything that affects a living
organism
ecology - study of the interactions between
organisms & environment
environmental science - interdisciplinary study
(ecology, biology, chemistry, geology, social
science, economics, politics and ethics) of the
relationship between humans & their environment.
Natural Capital
The Sun and Earth’s Natural Capital
Renewable Energy Sources (RES)
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RES
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solar
wind
waves
hydro
biomass
geothermal
tidal
Solar derived
Question
What is the big difference between solar energy and
energy from natural resources?
Question
What does it mean to be sustainable?
Sustainability –
‘Ability of a system to survive and function over time’
Exponential Growth
exponential growth –
quantity increases by a fixed
%-age in a given time
e.g. 2x
where x = 0, 1, 2, 3, 4, 5, 6,
7, …
x
2x
0
1
1
2
2
4
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8
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16
7
128
Complete the table:
World Population Growth
In less than 200 years,
the population went from
1 billion to 6 billion people
Why?
BIRTH RATE > DEATH RATE
Critical Environmental Problems
• population growth
• increasing resource use
• destruction/degradation of wildlife habitats
• extinction of plants and animals
• poverty
• pollution
Movie
Movie http://www.youtube.com/watch?v=aTjQO163P2E
Solutions
• management
• planning
• conservation
• education
• life style changes
• new ways of doing things
Views
VIEW 1 - Neo-malthusianism
Held by Environmentalists
‘we are living unsustainably’
As the population increases it puts strain on our natural resources
VIEW 2 – Cornucopian
Held by Economists and business leaders
‘there are no limits to human population growth that cannot be overcome
by human ingenuity and technology’
73% of habitable area of the planet has been disturbed.
How much more when the population increases from 6
to 8 billion by 2028?
End
• Review
1.2 Population Growth, Economic Growth,
and Sustainable Economic Development
Cultural change
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has given us more energy and
technology to alter our planet
allowed population expansion
increased our environmental
impact
What is in store for future generations?
Economic Growth
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Economic growth provides people with
more goods and services
– Measured in gross domestic
product (GDP) and purchasing
power parity (PPP)
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Economic development uses economic
growth to improve living standards
– The world’s countries economic
status (developed vs. developing)
are based on their degree of
industrialization and GDP-PPP
Global Outlook
Population Increase
developing countries > developed countries
End
• Review
1.3 Resources
Resource – obtained from the environment to
meet human demand, e.g. food, water, goods etc
Perpetual resources – renewed continuously,
e.g. solar energy
Renewable resources - can be replenished
relatively rapidly, e.g. forests, grasslands,
animals, water, air, soil
Nonrenewable resources can be exhausted & not renewed in human time
scales, e.g. fossil fuels, metallic minerals,
nonmetallic minerals
Renewable vs. Nonrenewable Resources
Renewable vs. Nonrenewable Resources
We can extend the supply of non-renewables: - Reduce Reuse Recycle
(requires less water, energy and other resources, produces less pollution)
Ecological Footprint
Ecological footprint – amount of land needed
to produce resources and assimilate waste for
an average person in a country
Includes Carbon FP, Food FP,
Housing FP, Goods + Services FP
Biologically productive land: 1.9 ha land per
person (1 ha = 10,000 m2)
Mean EFP is 2.3 ha per person
What is you EFP?
see CW1: have to
convert 1 ha = 2.5 acres
Ecological Footprint
When population reaches
10 billion, 1 ha per person
Larger for developed countries
e.g. Netherlands EFP
is 15x the countries area.
Example
How many times the country’s total land area is the combined
ecological footprint (EF) of all persons living in the USA?
EF = 9.6 ha/person
Total EF USA = 9.6 ha/person x (300 x 106) people = 3 x 109 ha
(3 billion hectares)
Area Land USA = 9631418 km2
100 ha = 1 km2,
so 1 x 107 km2 x 100 ha = 1 x 109 ha
1 km2
Ratio EF USA : Area Land USA
= 3 x 109 ha = 3
1 x 109 ha
Ecological Capacity
Humanity’s EFP
Humanity’s ecological
footprint has exceeded
earths ecological capacity
For US available land is 6.7 ha per person
Where is extra land coming from?
World Consumption
For developed countries to enjoy their standard of living, others must make do with less.
Environmental destruction and pollution do not know political boundaries
How long it will be until we begin to feel the impacts of our actions at home?
Ecological footprint in relation to available ecological capacity
Countries indicated by red dots were in an ecological deficit in 1997 when this
study was conducted.
End
• Review
1.4 Pollution
Pollution: undesirable change in physical, chemical, or
biological characteristics of air, water, soil, or food that
can adversely affect humans or other living organisms
Nonpoint Source: dispersed & often difficult to identify
sources (e.g., agricultural runoff)
Point Source: single identified sources of pollution (e.g.,
smoke stack or effluent discharge)
Point and Non-point Sources
Smol, 2002
What Types of Harm do Pollutants Cause?
- disrupts life-support systems
- damages health and property
- nuisances (Noise and smell)
What type of pollutant is CO2?
Severity
Severity - 3 governing factors:
1. Speciation
How active and harmful a pollutant is.
e.g. organic or methyl-mercury is highly toxic to humans whilst its
elemental form is also toxic, but to a lesser extent
2. Concentration
Measured in parts per million (ppm)  mg/kg  g/g
The dose makes the poison
3. Persistence
Degradable (nonpersistent) – may be broken down, e.g. sewage
Slowly degradable (persistent) – e.g. pesticides, oil, plastics
Nondegradable – e.g. lead, mercury
Dealing with Pollution
Prevention (the three R’s – refuse, reduce, reuse,
recycle) or Cleanup?
2 BIG problems with cleanup.
1.
With the population increasing this is only a temporary
solution, e.g. catalytic converter in cars
2.
Removes a pollutant from one environment into another
End
• Review
1.5 Environmental Problems
‘World Scientists' Warning to Humanity’
1,700 of the world leading scientists
issued an appeal in 1992 The Environment is suffering critical
stress in the following areas:
Some Major Problems
Tragedy of the Commons
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Problems cannot by solved by technical means
Problems raised by human population growth
and the use of the Earth's common property
natural resources
Examples:
– Depleting biodiversity
– Burning of fossil fuels
– Pollution of waterways and the atmosphere
– Logging of forests
– Overfishing of the oceans
Fresh water?
“If I do not use this resource, someone
else will. The little bit I use or pollute is
not enough to matter, resources are
renewable”
Cartoon
Solutions?
Management solutions:
Use less, restrict access, convert
to private ownership
Game
• Tragedy of the Bunnies
http://www.bunnygame.org
Connections
PxAxT=I
developing countries P is high A and T are low
developed countries A and T are high P low
Actually much more complicated than this!
End
• Review
1.6 Is Our Present Course Sustainable?
Guidelines for Sustainability
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Leave the earth as good or better than we found it
Take no more than we need
Try not to harm life, air, water, soil
Protect biodiversity
Help maintain Earth's capacity for self repair
Don't use potentially renewable resources faster than they are
replenished
Don't waste resources
Don't release pollutants faster than Earth's natural processes can dilute
or degrade them
Slow the rate of population growth
Reduce poverty
Advocates for environmentally sustainable economic
development call for a shift to using economic
rewards to encourage sustainable choices
Quote
What's the use of a house if you don't
have a decent planet to put it on?
–– Henry David Thoreau
How do I succeed in this course?
• be an active learner
• seek help (quickly) if needed
• complete all assignments, discussions and tests on
time