Transcript Global Warming

Environmental
Problems
Foundations of Science
Natural Cause: The universe
behaves in a predictable way
under “rules” that can be
determined through observation
and experimentation.
Uniformity: The “rules” are
constant through space and
time.
Foundations of Science
Parsimony: All other things
being equal, the simplest
explanation is the best.
Efficient Cause
cause & effect
Objective
Scientific “Method”
Observation
Question
Hypothesize
Test & Observe
Publish
Repeat (as
necessary)
Theorize
Publish
Repeat (as
necessary)
Environmental Science
interdisciplinary
a way of looking at things
scientific (& objective)
interconnected systems
human impact vs naturally occurring
• attempt to assign “responsibility”
What is the Environment?
definitions
circumstances or conditions that surround an
organism or group of organisms
the complex of social or cultural conditions that
affect an individual or community
for humans - our home - well suited to our
existence
natural world
•
•
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•
•
plants
animals
earth
air
water
“man-made”
• sociological
• scientific
• technological
“Tragedy of the Commons”
common property
usually owned by all (or the government)
examples
•
•
•
•
air
water
“air waves”
public land
commons are subject to poor use
open, unregulated access
benefits of use are focused
costs are widely distributed
Common Property
must be carefully managed
may privatize
cost of use & effects
• internalization of costs
• laws and taxes
commons (difficult)
• sale of public land
• sale of right to use
Global Climate Change
Earth’s climate has been changing
for over 4.5 billion years
wide scale of variability
causes of variability
Sun
physical Earth
life
Research Priorities
What is the scale of the current
change?
What are the causes of the current
warming?
What are the effects of human
activity?
Tools to Study Global
Change
geologic record
historical record
real time observation
mathematical modeling
Energy Balance
almost all energy ultimately from sun
earth’s energy cycle
incoming energy
• reflected 30%
• absorbed 70% (visible & IR)
outgoing energy emitted as IR
• (as much energy as received)
Earth warmed by energy between absorption
and emission
energy circulated by air and water movement
Earth’s Temperature
atmospheric retention of heat
“greenhouse effect”
H2O vapor, CO2, CH4, CFC’s
released by natural & human processes
Earth’s Temperature
historically
over last billion years: warmer with ice
ages
current ice age
• 2MYA to present: cooler with “interglacials”
• last glacial advance ended 10,000 yrs ago
• generally warming since
warming rapidly in last 150 years
Earth’s Temperature
CO2 changes
currently: 0.03% of atmosphere
recent highs
• “interglacial periods”
• 125K yrs ago and now
releasing stored CO2 from rocks & plants
• natural
• humans
current increase started in 1800's
other “greenhouse” gasses
human’s have increased release rate
Potential Effects of Global
Warming
local climate change
more rain
more violent storms
sea level rise
change in ocean circulation
complex response
Current Research On-line
http://www.globalchange.umich.edu/globalchang
e1/current/lectures/samson/climate_patterns/
http://www.giss.nasa.gov/research/
http://www.ncdc.noaa.gov/oa/ncdc.html
http://www.mos.org/cst/article/3369/
http://www.scotese.com/climate.htm
http://www.ngdc.noaa.gov/paleo/ei/ei_cover.html
http://www4.nas.edu/onpi/webextra.nsf/web/clim
ate?OpenDocument
More research and advocacy
on-line
American Petroleum Institute:
http://api-ec.api.org/environ/index.cfm
industry site
Natural Resources Defense Council:
http://www.nrdc.org/globalwarming/
environmental organization
Global Warming Information Page:
http://www.globalwarming.org/
“astroturf” site (no direct supporters listed)
Global Warming Early Warning Signs:
http://www.climatehotmap.org/
“environmentalist” site (supporters listed)
the Global Simulation Workshop
http://www.osearth.com/workshops/
commercial “environmentalist” site
worldwide use of energy
overall
oil - 36%
coal - 26%
natural gas - 23%
nuclear - 7%
biomass – 6%
hydro - 2%
geothermal & wind - 1%
U.S. consumes ¼ of worlds energy