Environment : Issues and Alternatives
Ch 1 p1
Miller, Ch 1 – Envir. Problems, Causes, and Sustainability
Intro – Fig 1.1 – Exponential Growth critical to understanding stress on
environment – there will be an ultimate “carrying capacity” of Earth for
humans…
But we don’t know what it will be……..
Key to understanding expon growth: growth is by a fixed percentage
Example - Increase your pennies by 100% every second…
1,2,4,8,16,32,64,128,256,512,1024,2028,4056, 8112,16224,32448 etc
5pts extra credit, due next lec..how many seconds does it take to get to 1
million dollars?

Why is expon growth important? – It’s not linear growth we worry
about…exponential growth is much more rapid.
1-1 Living sustainably
- Miller breaks our resources into solar and natural capital
- Concept of sustainability is that needs of inhabitants are met, but
natural capital is NOT depleted.
- If all natural capital is depleted, no resources exist for species survival
- Interesting analog with living off 10% interest of one million dollars
principal
As long as you live within the $100K/yr and don’t cut into principal,
this capital will sustain you indefinitely ….but if you overspend,
you can bankrupt yourself quickly. You moved from living
sustainably to unsustainably.
So what is the natural analog? – If we deplete all Earth’s resources,
through problems like exponentially growing population, we can’t sustain
life.
Example – global ecological demand on resources currently growing at
5%/yr, meaning resource demand is doubled every 14 yrs.
1-2 Growth and “Wealth Gap”
- Miller explains linear vs exponential growth in detail.
Fixed amount increase vs fixed percentage increase….both grow, but
percentage increase grows more quickly…go back to pennies
exercise…compare growth of 1 cent/sec vs 100%/sec.
- Graph this up : growth in cents vs time, each way; should look like
Fig 1-3
Ch 1 p.2
-
Human population growth is exponential – result is up to 73% of habitable
area of planet has been disturbed by human activities (Fig 1-5).

Economic growth discussion – developed vs undeveloped countries.
(Fig 1-6)
Developed countries have 20% of population, and 80-90% of world’s
wealth, utilize large amt of natural resources, and generate large amts of
pollution.
Developing countries show opposite stats: 80% of population, only 15% of
wealth.

Population growth discussion – pop growth very slow in developed
countries (.1%/yr), very high in undev. (1.7%/yr)…complicating factor is
that there are many more people of child-bearing age in undev
countries too, which Miller fears will fuel more rapid pop growth.

Sustainability – huge debate brewing about this issue….transcends
just science – everyone has concerns.
- Issue – how can you have economic development, that benefits
people, without depleting resources that are critical to everyone’s
survival?
- 2 key Technical points – there are finite resources, and there are
limits to Earth’s ability to absorb waste, pollution, etc.
Define sustainability (Herman Daly, economist) –
Sustainable development – “development without growth in the human
throughput of matter and energy resources that is beyond the ability of the
environment to supply and renew resources and to absorb or break down
the wastes we produce.”
In essence, we don’t want to overload our natural environment in either its
ability to yield resources or to absorb waste….
1-3 Resources
Define resources –
1. Ecological resource – habitat, food, water, and shelter.
2. Economic resource – used to meet human needs/desires – food,
water, shelter, manufactured goods, transportation, communication,
and recreation.
Ch 1 p. 3

Resources can be classified as renewable, nonrenewable , potentially
renewable.
1. Renewable resources – as name implies, a resource that either
regenerates itself or is perpetual in human terms (here, the sun is
considered perpetual and therefore its energy is a renewable resource).
Most authors define Miller’s “potentially” renewable resources as just
renewable. These can be replenished or regenerated on human or nearhuman time scales:
Trees
Grasses
Animals
Surface water
Groundwater
Fresh air
Fertile soil
Miller also includes biodiversity as a renewable resource. Diverse forms of
life provide diverse functions, generating wood, energy, chemicals,
medicines, and provide recycling, purification, and pest control.
Miller uses “potentially renewable” to emphasize fact that we can overdraw these resources, and essentially drive them to extinction if we use
them faster than their ability to self-regenerate. Thus he uses concept of
“sustainable development” to define a depletion rate less than the natural
replacement rate, vs “environmental degradation” to define a rate greater
than this replacement rate.

Economic analog – if you live off the interest of your investments (or
your checkbook) and don’t cut into the principal, you are living
sustainably. If you cut into your principal greater than the rate at which
you replenish your withdrawals (environmental degradation),
eventually there will be no money left.
If envir degradation occurs too much, what was a renewable resource (like
a rainforest) could become nonrenewable, for all practical purposes.
2. Non-renewable resources
Defined: resources that exist in a fixed quantity (on human time scale).
These are typically energy (oil, gas, coal) and mineral (iron, copper,
uranium, salt, sand, phosphates) resources.
Typical use cycle (Fig 1-12) shows that resources usually get depleted to
about 80%, then become uneconomic to extract.
Ch1 p. 4
Note that some non-renewables can at least be recycled (aluminum cans,
copper wiring, etc)
Some non-renewables can also be re-used. For example, old long neck
beer bottles in the 1940s & 50s would be returned and refilled at the
brewery.
1-4 Pollution
Defined: “Any addition to the environment that threatens humans or other
living organisms is called pollution”
Depending upon the author, some define pollution as being introduced
solely by humans, but Miller notes that pollution can come from natural
resources too, such as volcanic eruptions.
Most human-generated pollution emanates from major population centers,
or from large scale agricultural operations.
Pollution is generated from both point and non-point sources, and
routinely moves from one place to another via wind, water, and human
transfer (eg, solid waste transfer).
- Point sources (very specific source):
Smokestacks
Auto exhast pipes
Drains into lakes, rivers
- Non-point sources (dispersed source):
Fertilizer & pesticide runoff
Pesticide spraying
Harm associated w/pollution:
1. disruption of life support
2. damage to health and property
3. nuisance smells, tastes, sights
Factors controlling severity of effects:
1. chemical nature (its formula; eg, benzene, toluene, PCB, DDT)
2. concentration (in parts per million either by weight or by volume)
3. persistence (degradable vs non-degradable)
Ch 1 p.5
Biodegradation can occur with a large number of pollutants:
quick biodegradation happens with human sewage
slow biodegradation happens with some chemicals and plastics
many other pollutants are non-degradable (mercury, lead, etc)….these
can not be removed, at least naturally

Solutions to pollution:
- Prevent it
- Clean it
Prevention is more effective – stop it at the source
Cleanup has problems:
1. Trouble keeping up with increasing growth: example – we have
much cleaner cars than 20 yrs ago, but many more on the road
2. Cleanup in one area causes problems in another (eg, collect
garbage in one area, then burn it where it causes some air
pollution)
3. Cleanup cost can be high and place heavy economic burdens
on companies, workers, government)
Government (and you the voter) play an important role in pollution policy –
combination of incentives and penalties neede for reducing pollution.
1-5 Environmental and Resource Problems: causes and concerns
Series of inter-related problems (Fig 1-14)
Formula in Fig 1-15 shows how Miller describes environmental
impact
Population x Affluence x Technology = Impact
Diagram Fig 1-16 shows how different countries’ populations might
be factored into the equation
1-6 Cultural Changes and Sustainability
stages of human development have progressively impacted the
environment:
Hunter-gatherers
man as distinct species has been around close to 200,000 years
primarily a hunter-gatherer until 12,000 years ago – little impact to
environment, low pop growth due to high infant mortality and early death (
avg only 3-40 yrs)
Ch 1 p.6
So Miller contends these early humans definitely lived sustainably.
Agricultural revolution
At about 12,000 years BP, man began the agricultural revolution, resulting
in settled agricultural communities rather than a nomadic lifestyle.
Early farmers recognized importance of rotating crops from one patch to
another (fig 1-18), and letting a patch revegetate in order to build up
nutrients and minerals depleted by crops.
Miller says these farmers represented the first stage of man attempting to
“tame and manage nature”.
Industrial Revolution
In the mid-1700s, about 250 years ago, industrial revolution began. This
was the dawn of the modern era. All forms of growth started to expand
rapidly (exponentially).
Big switch, from wood (potentially renewable) to fossil fuels (nonrenewable);
Big switch from local, handmade goods to mass production in industrial
centers.
Factory economies spawned heavy smog from coal, hazardous working
conditions, lots of lung ailments. “Ash and soot covered everything”.
Per acre crop yield also rose, producing a stable food supply for many
people, and population began to increase at higher rate than previous
human history.
1-7 Is the present course sustainable?
So, are things getting better? Or worse?
This is a huge debate, with no easy answers. It is YOUR job to determine
what you think…don’t just accept the word of so-called experts, because
they all have agendas (especially Miller).
Miller is guilty of painting this as a black – or – white issue….people
(especially business people) are evil and are going to destroy the world, or
the environmental “good guys” are gonna save the world.
Reality is far more complicated than this…..I wish it were so easy.
Ch 1 p. 7
There ARE some important issues that we all need to work together upon:
 Pollution issues – cleanup vs prevention – this continues to be a
problem, and could become extremely serious as under-developed
nations continue to grow and industrialize.
 Species and habitat protection – there clearly are a number of
endangered species that need special consideration and protection.
But there are a number who are already coming back, and in some
places flourishing almost too rapidly (eg, Florida alligators).
 Environmental protection and restoration. Certain aspects of
environments and habitats must be managed adequately in order to
maintain biodiversity and healthy populations of plants and animals.
 Resource conservation – no doubt we are utilizing non-renewable
energy resources. But "experts” have been predicting that we only
have a 50-year supply of petroleum since the early 1800s, 200 years
ago. We continue to explore successfully and augment the reserve
base we deplete. This will NOT go on forever, but be careful of the
words of supposed experts.