Transcript Climate and Climate Change - Department of Environmental Sciences

The Environmental Movement
• Rachel Carson:
Silent Spring
• Effect of DDT in
the food chain
Point-Source Pollution
• Early problems were obvious
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point-source pollution
... the “bad guys” were someone “else”
... but the battles were tough
... progress has a price
• High costs of changing/regulating industry
– litigation
– retooling
Government Action
• Early Progress
– Earth Day 1970
– EPA 1970
– Clean Air Act 1970
– Clean Water Act 1972
– Marine Mammals Protection Act 1972
– Endangered Species Act 1973
– Safe Drinking Water Act 1974
What is the Science
in Environmental
Science?
Science
Systematized knowledge derived from
observation, study and experimentation
carried on in order to determine the nature
or principles of what is being studied
Assumptions of the Process of
Science
• We perceive reality with our five basic
senses
• Objective reality functions according to
certain basic principles and laws
Assumptions of the Process of
Science
• Causes and effects are explainable
• We have tools and capabilities to
understand basic principles and natural
laws
The Scientific Method
• Voted greatest scientific advancement
of the last Millennium
• Based on observation and fact
• Subject to verification by other
researchers
Scientific Method
Observation
Question
Further questions
Hypothesis
Test (e.g. experiment)
Supports hypothesis
Contradicts hypothesis
Which of the following are TESTABLE hypotheses?
Try suggesting an experiment to test it.
Exotic species are bad
The addition of phosphorus fertilizer increases algae
growth in fresh water habitats
The oil industry hurts the environment
The herbicide atrazine causes deformities in frogs
Tools for Science
observation
correlation
experimentation
Observation
 the first step in the process of science
 provides the ideas to generate hypotheses
Hypothesis: provides tentative explanations,
must be testable
benefits
•can be simple & cheap
(or high tech)
• can be done in the real
world
draw backs
• needs to be followed
with hypothesis testing
Correlation
(fabricated data for explanation purposes only)
Number fish species
16
12
8
4
0
1.5
3.5
Lake area (m2)
5.5
Correlation
can be done across space e.g. survey a large number
of lakes
 can be done across time, e.g. sample one lake for
many years (special statistical considerations)
benefits
• can be predictive
• can establish
association, (e.g. low
cancer associated with
high fiber diet)
• can be done in real
ecosystems
draw backs
• does not establish causation
Experimentation
manipulate one or few variables and measure response
variable (or dependent variable)
must have control and replication
benefits
• establishes probable
causation
draw backs
• usually on small scale (or
very expensive)
• can be artificial situation
Theories
• Consistent with all observations
• Has been supported by repeated testing
The scientific method is carried
out by people who may be:
Influenced by
cultural beliefs
Advocating a
position
Dishonest
http://www.drscience.com/
Junk Science
• Selective presentation (data omitted)
• Politically motivated distortion of
scientifically sound papers
• Attribution of false information to a
respected researcher or organization
– Wall street journal reports CDC finds
organic foods can kill you
Environmental Sciences:
Towards a Sustainable Future
Chapter 21
The Atmosphere: Climate and
Climate Change
Weather: day to day variation in temperature, wind,
humidity, and precipitation
Climate: average temperature and precipitation
expected throughout a typical year in a given region
"climate is what you expect, weather is
what you get."
The Atmosphere
Where weather takes place
Global warming and
the greenhouse effect
Some gasses and water vapor in the atmosphere
absorb and reemit solar energy, making earth warmer
than it otherwise would be.
Atmospheric CO2 concentrations are increasing
Photosynthesis by plants and algae, more
with light & in summer
C02
6 CO2 + 12 H20
carbon
dioxide
water
02
C6H12O6 + 6 H20 + 6 02
carbohydrate
water
oxygen
Respiration, emission of CO2 by all life,
all the time
C02
C02
C6H12O6 + 6 H20
carbohydrate
water
6 CO2 + 12 H20 + ATP
carbon
dioxide
water
energy
Carbon cycle: numerous exchanges of C
http://www.physicalgeography.net/fundamentals/9r.html
Other Greenhouse Gases And
Sources
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Water vapor
Methane
Nitrous oxide
CFC’s and other
halocarbons
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Hydrological cycle
Animal husbandry
Chemical fertilizers
Refrigerants
Atmospheric CO2 is rising
Will this cause increased temperatures?
What are some of the consequences
of increased temperature?
Global Surface Temperatures
Ice core data
shows strong
correlation
between
greenhouse
gasses and
temperature.
Hurricanes and Climate Change
For hurricanes to occur, surface ocean temperatures must
exceed 80 F. The warmer the ocean, the greater the
potential for stronger storms.
Rising sea levels, also caused in part by rising global
temperatures, intensify storm damage along coasts.
red indicates
area of temp >
84F
Predictions for Ohio
Water Supply and Pollution
• Lake levels expected to decline, more evaporation
• Reduced summer water levels; small streams & wetlands
may dry up
• Pressure to increase water extraction from the Great
Lakes
• Development and climate change will degrade the floodabsorbing capacities of wetlands and floodplains, resulting
in increased erosion, flooding, and runoff polluted with
nutrients, pesticides, and other toxins.
Predictions for Ohio
Agriculture
• Increased atmospheric CO2 and longer growing season
could boost yields of soybeans, corn, and wheat
• Severe rainstorms during planting and harvest seasons
will likely depress productivity
• Higher ozone concentrations can damage soybeans and
horticultural crops, countering positive impacts of a warmer
climate.
• Several climate changes will likely combine to create more
favorable conditions for a number of pests and pathogens.
Predictions for Ohio
Human Health
.
• Winter cold-related deaths will decrease, while summer
heat-related death is likely to increase.
• Some waterborne infectious diseases such as
cryptosporidiosis or or giardiasis may become more
frequent or widespread if extreme rainstorms occur more
often.
Predictions for Ohio
Water Supply and Pollution
• Lake levels expected to decline, more evaporation
• Reduced summer water levels; small streams & wetlands
may dry up
• Pressure to increase water extraction from the Great
Lakes
• Development and climate change will degrade the floodabsorbing capacities of wetlands and floodplains, resulting
in increased erosion, flooding, and runoff polluted with
nutrients, pesticides, and other toxins.
Agriculture
It is very difficult to prove that increased CO2
emissions cause increased temperature on Earth
List some of the risks involved in waiting for 100% proof
of causation.
How much risk are you comfortable with?
Precautionary Principle
Where there are threats of serious or irreversible
damage, the absence of scientific certainty shall
not be used as a reason for postponing costeffective measures to prevent environmental
degradation.
A closer look at anthropogenic (human) sources
of greenhouse gasses
Most emissions come from developed nations
Coal use emits disproportional amount of CO2
Transportation results in a lot of CO2 emissions
http://www.eia.doe.gov/oiaf/1605/ggccebro/chapter1.html
Tragedy of the Commons, Garrett Hardin, 1968
Benefit of new sheep
Cost of new sheep
10$ (sale price for
adult)
.01$ loss of
productivity due to
overgrazing