Title: Environmental Science Exam III Notes
1Environmental Science Exam III Notes
2- Sustainable
- Agriculture
- Recall Information from Presentation
3About 38 of the worlds land is used for
agriculture
- Land use in the U.S. (not including Alaska and
Hawaii). - Of this, roughly 61 is used for agriculture
either for crops or grazing. - Of that, roughly 2/3 of agricultural land, or 40
of all land is used for grazing animals to feed.
4(No Transcript)
5- Also, according to the U.S. Department of
Agriculture, farming and ranching are responsible
for 69 of all species endangerment in the United
States. - So, looks like we're killing endangered animals
in order to grow cows, pigs and chickens.
6Starvation
- There are more than 800 million people in the
world afflicted with starvation. The reason for
their hunger is not a global shortage of food,
but a string of interconnected forces like
poverty, population growth and lack of
education. - How many people starve to death each year?
- _at_ 5 million people per year.
- How many people starve to death each day?
- _at_ 30,273 per day !
7- The hunger trend is being combated by hundreds of
global organizations and well-meaning
governments, but the conditions of famine around
the world are proving nearly impossible to
eliminate.
8Kwashiorkor and marasmus are two types of
malnutrition that are the two extremes of
protein-calorie deficiency.
9Soil Formation I
- Physical events like fragmentation (by weathering
e.g., by temperature changes and abrasion) of the
parent material consisting of rocks or other
geological deposits
10Soil Formation II
- Chemical weathering occurs when water and other
substances react with parent material,
11Soil Formation III
- Biological events Organisms (e.g., lichens) also
play a role in weathering, Humus is the resulting
decaying organic matter that is formed and
constitutes an important ingredient of the soil.
12Soil degradation is a serious threat to humans
2004
13Barriers to a Sustainable Agricultural System
14Erosion
- is the wearing away and transportation of soil by
water or by wind. Worldwide 19 billion ha (47
billion acres) suffer from erosion and other
forms of degradation.
15- Desertification is the conversion of cropland,
pasture, and rangeland into desert or land too
arid to be farmed
16- The loss of fertile farmland to development
(farmland conversion)
17- The amount of irrigated cropland is substantial
and produces _at_ 33 of our food. There are many
problems with irrigation including salinization
(the buildup of salts in surface soil layers) and
overuse of water resources.
18- Approximately 10 of the worlds irrigated
cropland suffers from waterlogging
19- A loss of genetic diversity and a decline in
species that are cultivated could result in great
decreases in food production in the future.
20- The overapplication of fertilizers can also
damage soil and plants
21Possible solutions to our problems with our
agricultural system Part I
- Protecting Soil and Water Resources.
-
- Farmland Conversion can be reduced by regulations
- Water should be used more efficiently
- Appropriate use of fertilizers is needed to
replace nutrients in soil.
22Possible solutions to our problems with our
agricultural system Part II
- Crop rotation especially involving the periodic
planting of legumes that replenish Nitrogen, - A potential for increased food production is to
increase the amount of land in use. - Also eating lower on the food chain would
increase total crop yields
23- Agriculture, Biotech,
- and the Future
24- Approximately 850 million people are malnourished
and it plays a role in the death of 5 million
deaths/year. The Green Revolution was supposed
to have solved the problems, but instead it has
resulted in other problems
25(No Transcript)
26PESTS
- Pests consume or destroy _at_ 50 of the worlds
crops. Pesticides - chemicals that are used to
kill or control unwanted organisms or pests
(e.g., fungi, animals, and plants).
27Pests
- The perfect pesticide would be inexpensive,
affect only the target organism (narrow spectrum
instead of broad spectrum), have a short
half-life, and break down into harmless
materials. - B. Pesticides are widely used because their use
increases crop yields, and profits as well as
decreasing the incidence of insect-borne
diseases. Annually _at_ 2.75 million tons of
pesticides are used (22 in the U.S. and 57 in
Europe and other developed areas).
28(No Transcript)
29Problems associated with the use of pesticides
include
- Killing non-target species (e.g., beneficial
insects, natural predators, wildlife and fish) - Increasing genetically resistant species of
pests. - Biomagnfication and bioaccumulation
- Adverse affects to human health.
- Economic costs
30(No Transcript)
31(No Transcript)
32(No Transcript)
33How might we reduce the use of pesticides
- Increased organic farming
- Integrated pest management involves the use of a
variety of methods for pest control including
the selective use of synthetic and natural
pesticides, pheromones, the release of natural
predators, and modifications of farming
practices. - Bans and registration
- Education
34(No Transcript)
35(No Transcript)
36- Resource Management
- is the practice of harvesting potentially
renewable resources in ways that do not deplete
them (Withgott and Brennan).
37Forests and Forest Management Recall the
Sustainable Forestry Presentation
- At one time, almost 50 of the US, 75 of Canada,
and almost all of Europe were forested, but
demand for wood has led to deforestation. - Trees were harvested for fuel, building
materials, and in order to clear land for
farming. Negative impacts of the exploitation of
the remaining forests include but are not limited
to a further reduction in biodiversity, erosion,
the loss of carbon sinks, regional and possibly
global climate change, and changes in the water
cycle.
38Forests Part II
- The root causes of deforestation include the
developmentalist ethic, a lack of education
concerning the benefits of forests, the growing
human population, poverty, land ownership
patterns, and government policies that promote
overharvesting in several nations. - Concern about deforestation has led to an
interest in sustainable forestry.
39Rangelands and Range Management Protecting the
Worlds Grasslands
- Of the land that is in use for food
production, 26 of that is used for grazing
livestock and is called rangeland. It is mostly
unsustainably managed. - Despite that fact that leaves grow from the
ground up and can regrow if the lower ½ of the
plant (metabolic reserve) is left after grazing
and thus are resistant to limited grazing, many
ranglelands are overgrazed. This metabolic
reserve is destroyed by overgrazing
40Consequences of overgrazing
41Range Management involves the following
techniques
- The carrying capacity of rangeland needs to be
taken into consideration - Sectioning the land and using only one area at a
time for grazing and letting the other rest
(deferred grazing) - The distribution of the animals spreading them
out - Restoration efforts for deteriorated land
- Government policies to help achieve
sustainability of rangeland.
42(No Transcript)
43(No Transcript)
44- According to the World Resources Institute (WRI,
1992) "overgrazing is the most pervasive cause of
soil degradation . . . . In Africa and Australia,
overgrazing causes 49 and 80 percent,
respectively, of soil degradation, mainly in
semi-arid and arid regions." Although the share
of responsibility on the part of other influences
(the introduction of exotic species, fuel-wood
harvesting, the suppression of the natural fire
cycle, wildlife degradation and the conversion of
rangelands to croplands or human settlements,
etc.) has been emphasized in subsequent UNEP
publications (WRI, 1994), overgrazing has always
been considered the most important factor (Figure
3).
45(No Transcript)
46(No Transcript)
47Wilderness and Remote Areas.
- According to the US Wilderness Act of 1964 a
wilderness is defined as an area where the earth
and its community of life are untrammeled by man,
where man himself is a visitor who does not
remain There has been increasing pressure to
explore the remaining wilderness areas of the US
for oil and mineral exploration (current
situation in the Pacific Northwest involving gold
and national forests).
48There are four traditional reasons for the
establishment of protected lands
- Land that is enormous, beautiful, or has unique
features are favored because of monumentalism -
- Land with recreational value
- Land that provides utilitarian benefits (like
protected water sheds and water sources) - Land that lacks economically valuable resources
- A fifth reason has recently been added, saving
land in order to preserve biodiversity.
49(No Transcript)
50(No Transcript)
51- Urbanization
- and
- Livable Cities
52Urbanization involves people shifting from living
in rural areas to urban areas.
- Occurred due to the Industrial Revolution and has
increased in the past 50 years, from 30 of the
worlds people living in urban areas to 48
living there currently. - However, in developed countries, people like to
escape the city and have developed suburbs in
order to have larger homes with lawns. - Despite the growing suburbs in developed nations,
urban living continues to increase worldwide. - Two reasons for the growth of urbanization are
that more people are moving from the rural areas
into the cities and the overall growth of the
human population.
53(No Transcript)
54(No Transcript)
55- The desire to live in a suburban environment has
increased what is called sprawl in developed
countries (especially in the U.S.) - One definition of sprawl - the spread of
low-density urban or suburban development outward
from the city center. - Another definition of sprawl - the physical
spread of development at a rate greater than the
rate of population growth.
56Two causes of sprawl
- Human population growth
- The per capita land use- each person takes up
more land
57 Problems associated with sprawl Part I
- Increased need for fossil fuels to support
transportation into the cities where jobs,
entertainment, shopping opportunities exist. - Pollution associated with transportation and
water pollution related to runoff from homes,
driveways, roads and other impervious surfaces.
58Problems associated with sprawl Part II
- Health problems that are promoted by people using
cars too much and developing very sedate lives. - Short-sighted land use and decreases in natural
areas. Farmland conversion is a serious problem
that may come back to haunt future generations,
and as humans continue to spread out they
displace other endemic species (e.g., bears and
cougars) from the land that they need for
existence.
59So what can help humans promote sustainability as
far as housing goes.
- City and County Growth Management Plans allow for
zoning sections of available land for particular
uses. This would help control sprawl by creating
urban growth areas for housing, industrial areas,
and natural lands. - Unfortunately these Plans are the sources of
controversy and different ideas on land use.
While conservationists promote such plans,
developers (housing etc.) prefer to be able to
continue to add low density housing and continue
sprawl. - Smart growth and the new urbanism
- Alternative methods of transportation especially
mass transit - An important part of planning for smart growth
is including open space and recreation areas.
60(No Transcript)
61- Environmental Health
- and
- Toxicology
62Environmental Hazards
- Physical. Natural processes can negatively
affect human health. Disasters, UV light
exposure etc. can have major even life ending
affects. Although some of these processes are
natural, human activities may also influence the
frequency and severity of some of these
phenomena. For example, the hole in the ozone
allows more UV light to penetrate the atmosphere.
63(No Transcript)
64- Chemical hazards. Many chemicals that are used
by humans are hazardous or toxic to us and/or
organisms in the environment. Pesticides for
example are used to increase crop yields but many
of these cause serious health problems if humans
come in contact with them.
65(No Transcript)
66- Biological hazards. Infectious diseases would
fall into this category. These are caused by
various microbes, but humans may play roles
outbreaks, epidemics, or even pandemics due to
our activities such as deforestation of tropical
rain forests and encountering emerging viruses
(e.g., Ebola). See figure 14.2 (both texts) for
the leading causes of death across the world in
2004 and the leading causes of death by
infectious disease
67(No Transcript)
68- Cultural hazards. Some are choices (smoking,
overeating etc.) and others are related to
socioeconomic standings (we talked earlier about
Environmental Justice and often toxic waste can
be located in areas close to predominately poor
people).
69(No Transcript)
70- According to the US Resource Conservation and
Recovery Act of 1976 wastes are considered as
toxic if they - cause or significantly contribute to an increase
in mortality or an increase in serious
irreversible, or incapacitating reversible,
illness or pose a substantial present or
potential hazard to human health or the
environment when improperly treated, stored,
transported, disposed of, or otherwise managed. - To be precise toxic a narrow group of
poisonous substances which may cause serious
injury or death and hazardous a wider group of
dangerous wastes that present health or
environmental risks (immediate or long-term).
71- Heath Risks include immediate negative effects
(poisoning), cancer, birth defects, and genetic
damage. - http//www.youtube.com/watch?vfD4-jSZamTo
72(No Transcript)
73Sustainable solutions to the presence of toxins.
- Preventing the release of toxins is better than
dealing with cleanup. Regulations and market
incentives are methods that reduce the production
of these chemicals. - Previously toxic chemicals were dealt with after
they were produced by various methods Deep-well
injection into porous geological formations or
salt caverns, discharge of liquids (treated and
untreated) into municipal sewers, rivers, and
streams, placement of liquids or sludges into
surface pits, ponds or lagoons, storage in lined
dumps, and dumping into sanitary landfills. - Alternative methods include destroying hazardous
wastes and immobilization (putting it into a
solid form that is easier to deal with and less
likely to contaminate the environment).
74(No Transcript)
75-
- END OF NOTES For EXAM III