Transcript PPT File - Department of Geological & Atmospheric

Global Climate Change:
Science and Consequences
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
[email protected]
Energy Awareness Group Ames Public Library, 7 September 2005
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Outline
Evidence for global climate change
 Future atmospheric carbon dioxide
concentrations
 Simulations of global climate and future
climate change
 Impact on global food production and freshwater availability
 Implications for the Midwest
 “Dangerous anthropogenic interference with the climate system”?
 What can I do?
 Hurricane Katrina
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Carbon Dioxide
and Temperature
Carbon Dioxide
and Temperature
2004
Carbon Dioxide
and Temperature
2040
2004
Carbon Dioxide
and Temperature
Stabilization at 550 ppm
Carbon Dioxide
and Temperature
“Business as Usual”
(fossil intensive)
2100
Associated Climate Changes
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Global sea-level has increased 1-2 mm/yr
Duration of ice cover of rivers and lakes decreased by 2 weeks in N.
Hemisphere
Arctic ice has thinned substantially, decreased in extent by 10-15%
Reduced permafrost in polar, sub-polar, mountainous regions
Growing season lengthened by 1-4 days in N. Hemisphere
Retreat of continental glaciers on all continents
Poleward shift of animal and plant ranges
Snow cover decreased by 10%
Earlier flowering dates
Coral reef bleaching
Source: Intergovernmental Panel on Climate Change, 2001 Report
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Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
NASA photographs show the minimm Arctic sea ice
concentration in 1979 at left and in 2003.Satellite passive
microwave data since 1970s indicate a 3% decrease per
decade in arctic sea ice extent.
Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent.
(Illustration from NASA) (http://www.nrdc.org/globalWarming/qthinice.asp)
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QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
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are needed to see this picture.
http://www.earth-policy.org/Indicators/CO2/2004.htm
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Agung, 1963
El Chichon (1982)
Mt. Pinatubo (1991)
Hansen, Scientific American, March 2004
Source: Jerry Meehl, National Center for Atmospheric Research
Source: National Center for Atmospheric Research
The planet is committed to
a warming over the next
50 years regardless of
political decisions
Source: National Center for Atmospheric Research
Source: Intergovernmental Panel on Climate Change, 2001 Report
40% Probability
5% Probability
Source: Intergovernmental Panel on Climate Change, 2001 Report
Climate Change
Projected for 2100
Rapid Economic
Growth
Slower Economic
Growth
Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate
Impact Assessment (www.acia.uaf.edu) Cambridge University Press
(www.cambridge.org).
Kennedy Space
Center
Impact of a 1-m
rise in sea level
on low-lying areas
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
Source:
Corell, R. W., 2004: Impacts of
a warming Arctic. Arctic
Climate Impact Assessment
(www.acia.uaf.edu) Cambridge
University Press
(www.cambridge.org).
IPCC Summary for
Policy Makers
 An
increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system
 Emissions of greenhouse gases and aerosols
due to human activities continue to
alter the atmosphere in ways that
are expected to affect the climate
IPCC Summary for
Policy Makers, cont’d
 There
is new and stronger evidence that
most of the warming observed over
the last 50 years is attributable
to human activities
 Anthropogenic climate change will persist
for many centuries
http://www.grida.no/climate/vital/37.htm
For the Midwest
Warming will be greater for winter than summer
 Warming will be greater at night than during the
day
 A 3oF rise in summer daytime temperature triples
the probability of a heat wave
 Growing season will be longer (8-9 days longer
now than in 1950)
 More precipitation
 Likely more soil moisture in summer
 More rain will come in intense rainfall events
 Higher stream flow, more flooding
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Climate Surprises
 Breakdown
of the ocean thermohaline
circulation (Greenland melt water)
 Break-off of the West Antarctic Ice Sheet
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Kennedy Space
Center
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
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What Consitutes “Dangerous
Anthropogenic Interference with
the Climate System”?
James Hansen, Director of the NASA Goddard
Institute for Space Studies:
* Radiative forcing limit: 1 Watt/ m2
* 1 oC additional rise in global mean
temperature
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Agung, 1963
El Chichon (1982)
Mt. Pinatubo (1991)
Hansen, Scientific American, March 2004
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
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Tropical Weather
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Weather Underground: http://www.wunderground.com/tropical/
Saffir/Simpson Hurricane Scale
CAT
1
Winds & Effects
Surge
74-95 mph
4-5 ft
No real damage to building structures. Damage primarily to unanchored mobile homes,
shrubbery, and trees. Also, some coastal flooding and minor pier damage.
2
96-110 mph
6-8 ft
Some roofing material, door, and window damage. Considerable damage to vegetation, mobile
homes, etc. Flooding damages piers and small craft may break their moorings.
3
111-130 mph
9-12 ft
Some structural damage to small residences and utility buildings, with a minor amount of
curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller
structures, with larger structures damaged by floating debris. Terrain flooding inland.
4
131-155 mph
13-18 ft
More extensive curtainwall failures with some complete roof structure failure on small
residences. Major erosion of beach areas. Terrain may be flooded well inland.
5
155 mph+
18 ft +
Complete roof failure on many residences and industrial buildings. Some complete building
failures with small utility buildings blown over or away. Flooding causes major damage to lower
floors of all structures near the shoreline. Massive evacuation of residential areas may be
required.
US Army Corps of Engineers
Category 5
Winds greater than 155 mph
Shrubs and trees down; considerable damage to roofing; all signs down.
Severe and extensive damage to windows and doors
Complete roof collapse
Destruction of glass in windows and doors
Some complete building failures
Small buildings overturned or blown away
Complete destruction of mobile homes
Storm surge higher than 18 feet above normal
Major damage to lower floors of all structures less than 15 feet above sea level
within 500 yards of shore
Low lying escape routes inland cut off by rising water three to five hours before
hurricane center arrives
Massive evacuation of residential areas on low ground within five to 10 miles of
shore possibly required
Catastrophic Hurricanes: Category 3 or larger
Katrina: Category 5, Winds > 175 mph, Storm surge > 25 ft
http://www.sas.usace.army.mil/em/emhurcatinfo.htm
What Can I Do?
 Conserve
energy
 Adopt a simpler lifestyle:
– “Elegant simplicity”
– “Sophisticated modesty”
– “Affluence lite”
Sustainable Development:
To meet the needs of the present without
compromising the ability of future
generations to meet their needs
Brundtland Commission (World Commission on Environment and Development)
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Summary
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Climate change is real and we need to be doing something
about it
The longer we wait, the fewer our options
Regional patterns of warming will be complicated
Climate surprises can’t be
discounted
We need dialog on what constitutes
“dangerous anthropogenic
interference with the climate
system”
More intense hurricanes can be expected
in the future due to global warming
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For More Information
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For peer-reviewed evidence supporting everything you have seen in
this presentation, see my online Global Change course:
http://www.meteor.iastate.edu/gccourse
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Contact me directly:
[email protected]
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For a copy of this presentation:
http://www.meteor.iastate.edu/faculty/takle/
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