Transcript coal

OUR Ecological Footprint - 12
1.
12
iCompost:
Meals, Peels, and Fields
Campus Compost Forum
Come enjoy locally produced food and
discuss issues surrounding our food sustainable campus.
Wednesday, November 19, 7:00 PM
YMCA building, Latzer Hall (main level)
Sponsored by Students for Environmental Concerns
Objectives
• I. Human Use of Sun’s Energy for Fuel
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Relevant Ecological Concepts
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Past formation of Fossil Fuels
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Present-day Use of Non-renewable Fossil
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Fuels
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Present-day Need for Renewable Fuels
• II. Human Use of Sun’s Energy for Food
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Relevant Ecological Concepts
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Challenges + Approaches to Feed 7-10 billion
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Consequences of Moving Down Food Chain
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Comparison of Diets across Earth
I.
Human Use of Energy for Fuel:
relevant ecolgoical concepts:
• Sun: origin of (almost) all energy that humans
use
• Ecosystem = energy-transforming machine
• Photosynthesis: sun energy transferred to
chemical bond energy
• Respiration: release (and transfer) of chemical
bond energy; generation of heat
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Aerobic
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Anaerobic: less release as heat
• Incomplete decomposition: accumulate biomass
PAST SCENARIO:
Accumulation of chemical bond
energy from past photosynthesis
• A. Production > Decomposition
• B. Death, then into decomposer food web
• C. Bury by sediments; anaerobic -->
deconposition slowed and incomplete
• D. Organic matter (biomass) transformed
to fossil fuels
Chemical Fossil Fuels from Geologic
Composting!
Physical Transformation of Organic
Matter
• When? Carboniferous - 3-400,000,000 yrs ago
• Where?
• Ocean:
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Algae (diatoms)
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Sedimentation
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Pressure/heat
• (Crude) oil + natural gas
Where? Land
• Woody plants in swamps
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Biogas via anaerobic respiration by bacteria
• Incomplete decomposition; much energy
remains
• Peat (a fuel)
• Sedimentation; weight squeezed out water
• Pressure + heat transformed
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wood fragments --> thermogenic natural gas
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leaves + wood --> oil + coal
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If anaerobic -- S in coal
• Trapped by overlying sediments
• Retrieval by drilling/strip mining
coal
Major coal deposits in USA red = high in S
Chemical transformation of organic
matter
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Lipids, proteins, carbos, lignin, cellulose
Kerogens (complex heavy hydrocarbons)
Heat -->
Lighter hydrocarbons by breaking bonds of
kerogens
PRESENT: break fossilized chemical
bonds
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Uses:
Drive ‘machines’
Heat
Electricity
Which fuels used for which use?
Relation of oil to gasoline
Relation to electricity
Sources
Relative cleanliness
What’s in a barrel
of oil?
How is electricity made and used?
Speed of Depletion of Non-renewable
Energy Sources
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How old are the sources?
When were they discovered + put to use?
What % have we used?
What is projected time of depletion?
• "There are currently 98 oil producing
countries in the world, of which 64 are
thought to have passed their geologicallyimposed production peak, and of those 60
are in terminal production decline."
Renewable alternative fuels - relate to
sun’s energy
•Solar
•Wind
•Biofuels (see PPT on 203 website)
• Seed (e.g. corn) -> ethanol
• Vegetable oil (from seed) -> biodiesel
• Crop residues (e.g corn stalks) +
• Non-crop cellulose
(e.g. switch grass + Miscanthus) -> ethanol
EBI: Energy Biosciences Institute
UI + U Cal-Berkeley
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Humans + Food Energy - Relates to:
• A. Population size +
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need (‘demand’ for animal food
• B. Primary and secondary productivity
• C. Trophic level of consumption
• D. Ecological efficiency
• E. Land use + landscape/conservation ecology
Global variation in estimated NPP Humans consume 40% of global NPP!!
What was the ‘Green Revolution’?
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A. Begun in 1945 to improve wheat production
in Mexico
B. Spread to all major continents
C. Used genetics and new technologies
D. Removed 2 major limiting factors:
Water + Nutrients
E. Funded by Rockefellow + Ford Foundations
Challenges for future:
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Less water for irrigation
Increasing temperatures -> drought
Loss of land to non-farm uses
Increased fuel costs
Increased fertilizer costs
Fewer new technologies on horizon
• Plan B Lester D. Brown Earth Policy Institutue
How to feed 7-10 billion well!
1. Improve land (plant) productivity
• A. Increase multi-cropping
• B. Improve water-use efficiency +
plant less water-demanding crops
• C. Move down food chain - less water to
produce animal feed
• D. Raise cost of water
• E. Put local people in charge to manage resources
2. Produce animal protein more
efficiently.
• A. 38% of grain used as animal feed in world
• B. variation in efficiency in convert grain to protein
beef = low aquaculture herb. fish = high
• C. variation among countries in type of meat eaten
China = # 1 = pork; 2nd in world = chickens;
fish on rise, too
• D. most soybeans used as grain for animal food;
has improved efficiency greatly
3.New animal protein production systems
• A. Milk in India: feed animals with roughage
• B. Use crop residues (straw/corn stalk) for cows
• C. China aquaculture: 4 fish at different trophic
levels
Why does human population size depend on
our trophic level?
Figure 2
4. Move down food chain
• A. How many people can earth support depends at our trophic level
Country
kg grain/person /yr billions supported
• USA
• Italy
• India
(almost all to humans)
• B. Of our 800 kg grain,
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? eaten as grain; ? to feed animals
• C. Complete table below:
Cultural Evolution of Diet
• A. Diets include carbos + protein
• B. Must have amino acid complementarity ->
can get all required AAs from plants
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e.g. L.A.: Beans + rice (corn)
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Asia: Soybeans + rice
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Middle East: Chickpeas + wheat/millet
What do all three have in common to get
a lot of N?
Government Policies Under Debate
• A. Plant corn for food or fuel?
• B. Farm bill with farm subsidies
The Hungry Planet
Peter Menzel
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Range
Item
$ spent on food
Calories in diet
Sugar used
Obsesity level
Meat consumption
•Calculate your daily required calories
• A. Height (in)
• B. Activity level
• C. BMI (body mass index)
18.5 (small boned)
24.99 (large boned)
25-29.99 = overweight
>30
= obese
(60% of US = overweight or obese)
• D. Weight (lb)
• E. Calories if 30 yr
(add 7 female or 10 male for each year below 30)
• F. Calories for my age __________