Transcript ENVI 30 Environmental Issues - University of San Diego Home Pages

I. Scientific Method
A. Process
1. Observation
• Careful; Include as many parameters as possible
• Observations  Induction  Question  Hypothesis
2. Question
3. Hypothesis
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Possible cause
Reflect past experience (educated guess)
Multiple (consider alternative explanations)
Testable
Falsifiable
4. Prediction
• Hypothesis/Principle  Deduction  Prediction
5. Experiment
• Experimental group, Control group, Replication
6. Results/Interpretation
7. Scientific Theory
I.
Scientific Method
B.
Bias
1.
Sampling Bias
• Our view of the world is conditioned very strongly by the
observational methods we use
• Ex: Counting whales vs. bacteria vs. viruses
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Methods vary considerably, depending on the temporal
and spatial scales of interest
• Ex: How is global temperature measured? Sea level?
2.
Assumptions
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3.
Important to recognize inherent assumptions
• Ex: 14C dating of wooden artifacts
Paradigms
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Generally accepted model, conceptual framework or set of
belief(s) about a particular topic
• Ex: Dinosaurs went extinct because of global climate
change precipitated by an asteroid
Paradigms may not be permanent
• Can be discarded/replaced by better explanation
(paradigm shift)
• Ex: Heliocentric solar system, continental drift
Paradigms may become so entrenched that people ignore
contradictory evidence or modify evidence to match paradigm
IPCC 2007
IPCC 2007
I.
Scientific Method
B.
Bias
1.
Sampling Bias
• Our view of the world is conditioned very strongly by the
observational methods we use
• Ex: Counting whales vs. bacteria vs. viruses
•
Methods vary considerably, depending on the temporal
and spatial scales of interest
• Ex: How is global temperature measured? Sea level?
2.
Assumptions
•
3.
Important to recognize inherent assumptions
• Ex: 14C dating of wooden artifacts
Paradigms
•
•
•
Generally accepted model, conceptual framework or set of
belief(s) about a particular topic
• Ex: Dinosaurs went extinct because of global climate
change precipitated by an asteroid
Paradigms may not be permanent
• Can be discarded/replaced by better explanation
(paradigm shift)
• Ex: Heliocentric solar system, continental drift
Paradigms may become so entrenched that people ignore
contradictory evidence or modify evidence to match paradigm
Technology – Developments
II.
A.
Observation
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Satellite-based sensors
Automated monitoring equipment
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Novel technology
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B.
Ex: TAO/TRITON array
Ex: acoustic instruments
Powerful computers
Real-time communication (fiber, internet, satellite)
Communication
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C.
Global communication technology
Extensive scrutiny (scientific, non-scientific)
Intense media coverage
Mitigation/Alternatives
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D.
Emissions control (air, water)
Water purification (desalination, reclamation)
Energy
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Nuclear, solar, wind, geothermal, hydroelectric, fuel cells,
ocean (tides, waves, currents)
Transition in energy use: Biomass  Coal  Oil/Natural
gas & Uranium
World Fuel Production & Energy Use
FUEL
Biomass (6-18 MJ kg-1)
1800
1900
1990
1,000
1,400
1,800
10
1,000
5,000
Oil (42)
0
20
3,000
Uranium (90 million)
0
0
??
Coal (14-32)
ENERGY
Total
Indexed (1900 = 100)
1800
1900
2000
250
800
10,000
31
100
1,250
Fuel values in millions of metric tons; Energy values in mmt oil equivalent
- More energy used in 20th century than all of human history before 1900
McNeill, 2000
Technology – Developments
II.
E.
Packaging/Processing
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F.
Canning
Bottling
Freezing
Freeze drying
Global Commerce
1.
Developments
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2.
Refrigerated long-haul trucks/containers/train cars
Interstate highway & railroad systems
Advances in food processing/storage
Selective breeding/genetic modification
Consequences
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Increase in tonnage of food shipped internationally
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898 vs. 200 million tonnes in 2001 vs. 1961
2000: Wholesale market in Chicago – Average kilogram of
produce traveled >2400 km from farm to plate (25% increase
vs. 1980)
Typical supermarket
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30,000+ items
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50% produced by 10 multinational companies
Technology – Developments
II.
F.
Global commerce
3.
Environmental Effects
a.
b.
c.
d.
Air pollution – Transportation
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Ex: Bottled water
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Nearly 25% of all bottled water transported
internationally
Release of GHGs
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Production (e.g. fertilizer, flatulence), transportation
Waste production
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Ex: Bottled water
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89 billion liters/yr  1.5 million tons plastic waste (WWF,
2001)
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154 billion liters in 2004 (Earth Policy Institute)
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>1 billion water bottles in CA trash/yr (CA Dept of
Conservation, 2003)
Resource use
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Ex: Bottled water
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2004 – Plastic bottle production used ~9 million barrels
of oil, enough to fuel 600,000 cars for a year (EPI)
Earth Policy Institute
Technology – Developments
II.
F.
Global commerce
4.
Environmental Effects
e.
f.
5.
Agricultural diversity
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Conversion to monocultures  Loss of diversity
Environmental degradation
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Ex: Canals/Locks on Mississippi  Biodiversity
loss (e.g. aquatic plants, inverts, fishes, birds)
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Ex: Dredging/Development of Pantanal (largest
wetland in South America – 140,000 km2 ~IL) 
Damage to biodiversity hotspot
Health Concerns
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Ex: 2003 – Green onions from Mexico  600 people in
PA with hepatitis, 3 deaths
Ex: 2006 – Spinach from CA  200+ people in 26
states sick from E. coli, 4+ deaths