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Global Climate Change:Global Climate Change:Global Climate Change:Global Climate Change:Scales and ComplexitiesScales and Complexitiespp
“Left” side of screen“Left” side of screen “Right” side of screen“Right” side of screen
Climate Change/VariabilityClimate Change/VariabilityE th’ hi t (4 6 billi ) i fill dEarth’s history (4.6 billion years) is filled with climate changes at all scales:– warmer intervals, colder intervals– changes in atmospheric compositionchanges in atmospheric composition– intervals of different land, ocean, mountain
distributiondistributionClimatic variability refers to fluctuations in the characteristic (expected!) elements--mainly TA and P y A
MS Climate Controls:MS Climate Controls:Location
T i t l idl tit d– Tropics to lower midlatitude– Bermuda High
W t li /t d– Westerlies/trades– Continent/Gulf of Mexico
cP vs mT air masses– cP vs mT air masses– Frontal passages, hurricanes, thunderstorms,
tornadoestornadoesResult – humid subtropical climate (less than 8% of land surface))
GCM forecast for July 2029 temp (mean GCM forecast for July 2029 temp (mean change = +1.5change = +1.5ooC) [notice geographic nonC) [notice geographic non--gg ) [ g g p) [ g g p
uniformity]uniformity]
Source = Goddard Institute for Space Studies
Comparison: Comparison: One state vs aOne state vs aOne state vs a One state vs a hemispherehemisphere——geographic nongeographic nongeographic nongeographic non--uniformity!!uniformity!!
Proof of Global Warming!!Proof of Global Warming!!
What Is The Evidence for Past What Is The Evidence for Past GlobalGlobal Changes in Climate?Changes in Climate?GlobalGlobal Changes in Climate?Changes in Climate?
Instrument measurements--150 years at bestHistorical data--1000 yearsP d tProxy data:– Continental glaciation (landforms, etc.)– ice sheets: cores, isotope analysis, SL changes– sediments: lake/sea floorsediments: lake/sea floor– fossils, pollen, tree ringsTh d liThese are used to reconstruct past climates
What Are Possible Causes of What Are Possible Causes of Climate Changes on These Scales?Climate Changes on These Scales?Climate Changes on These Scales?Climate Changes on These Scales?
Natural causes (in order of scale)Anthropogenic causes--CO O ??Anthropogenic causes--CO2, O3 ??
Fox huntingFox hunting
Continental DriftContinental Drift
Milankovitch Cycles: Orbital Eccentricities = Variations in Milankovitch Cycles: Orbital Eccentricities = Variations in Insolation??Insolation??
“Stretch”“Stretch”----100,000 year 100,000 year cyclecycle
“Wobble”“Wobble”----26,000 year cycle26,000 year cycle“Roll”“Roll”----41,000 year cycle41,000 year cycle
Sunspot Sunspot activityactivityactivityactivity
MaunderMaunder
Sunspot outbreakSunspot outbreak normalnormal
Maunder Maunder Minimum: 1645Minimum: 1645--17151715——less than less than one normal year’sone normal year’sone normal year’s one normal year’s worth in a 70worth in a 70--yr yr period=coldest period=coldest part of Little Ice part of Little Ice AgeAge
Mount St. Helens EruptionMount St. Helens Eruption----May 18, 1980May 18, 1980(Volcanic Ash Blown into the Atmosphere)(Volcanic Ash Blown into the Atmosphere)
Approximate volume of volcanic debris Approximate volume of volcanic debris emitted during some wellemitted during some well--known eruptionsknown eruptions
Tambora ejected Tambora ejected over 100 times moreover 100 times moreover 100 times more over 100 times more ash than did Mount ash than did Mount St. HelensSt. Helens——1816=“year without 1816=“year without a summer”a summer”
Carbon dioxide concentrations over the last 1000 yearsCarbon dioxide concentrations over the last 1000 years
Rapid increase Rapid increase since 1850 is tied since 1850 is tied t f il f lt f il f lto fossil fuel to fossil fuel emissionsemissions
Calculate amount of CO2 released by Calculate amount of CO2 released by burning of fossil fuels since 1958 (260 b tons)burning of fossil fuels since 1958 (260 b tons)
Emissions more than enough toEmissions more than enough to cause the observed increasesBut, measured rate of increase is 44% less than the total emissionsPuzzle—where is the “missing” 44%?Answer—”mopped up” (absorbed) by oceans and terrestrial biosphere
The The Balance Balance Balance Balance
of of NatureNatureNatureNature
Long-term Carbon Dioxide Atmospheric Concentration, Vostok Ice Sheet, Antarctica
400 000 years
290
310400,000 years
250
270
n (p
pm)
230
250
ncen
tratio
n
190
210
CO
2 Con
150
170
2 4 7 7 6 8 6 1 2 7 1 0 0 0 9 6 4 0 0 4 5
2342
3388
4
8572
7
1125
77
1257
46
1328
18
1382
26
1643
41
1915
92
2081
77
2172
71
2267
10
2392
50
2538
80
2686
79
2878
46
3033
34
3189
80
3352
90
3730
14
4140
85
Age of Entrapped Air, Yr BP
Reconstruction of Past Reconstruction of Past ClimatesClimates
Let’s look at what is mostly acceptedLet s look at what is mostly accepted as the history of climate on earth– throughout geologic time– in historic times– in the most recent yearsTh l k t f fl t tiThen look at causes of fluctuations we are experiencing today (measured!)
QuaternaryQuaternary
GeologicGeologicGeologic Geologic perspective on perspective on climateclimateclimate climate changechange——4.5 4.5 billibillibillion yearsbillion years
Last 600,000 yearsLast 600,000 years
100 000100 000--year glaciationsyear glaciations100,000100,000--year glaciationsyear glaciations
10,00010,000--year interglacialsyear interglacials
Last 11,000 yearsLast 11,000 years
LastLastMedieval maximumLast Last
glaciationglaciation
Historic records (1000 years)Historic records (1000 years)
Thermal Thermal max of max of early early 1900s1900s
Valley Valley ForgeForge
Variation of Annual Mean Land Surface Variation of Annual Mean Land Surface Temperature of the World, 1866Temperature of the World, 1866--2005 2005 p ,p ,
(departures from 1951(departures from 1951--80 mean)80 mean)
Thermal max of early y1900s
“Hockey “Hockey S i k”S i k”Stick” Stick” graphgraphg pg p
When did the instrumental When did the instrumental record begin?!record begin?!
The analysis missed a couple of major, The analysis missed a couple of major, historic climate fluctuationshistoric climate fluctuations ——is it credible?is it credible?historic climate fluctuations historic climate fluctuations is it credible?is it credible?
Within a trend of overall cooling, global temps can vary widely, creating warming trends like we are now experiencing
Remember, the “now” is the end of a Remember, the “now” is the end of a very long story of ups and downs….very long story of ups and downs….
Illustration of “perspective”Illustration of “perspective”You may have seen this structure before, but it can still get your attention.
p pp p
Did you know the world's tallest building is in Canada?
It's called the Canadian National Tower in Toronto and is used forIt s called the Canadian National Tower in Toronto and is used for telecommunications.
It's height is 553.3 meters or 1,815 feet so you know it's been g yphotographed a lot.
I'm a big fan of architecture and have gone back and looked at thisphoto several times.
It's truly amazing. See for yourself....
Distribution of temperature stations (a) now (b) preDistribution of temperature stations (a) now (b) pre--19001900
(a)(a)
(b)(b)
Temperature measurements prior and Temperature measurements prior and subsequent to changing from old max/min liquid subsequent to changing from old max/min liquid q g g / qq g g / q
in glass thermometers to new electronic in glass thermometers to new electronic thermometersthermometers
(Karl et al., 1995)
Hadley NASA
Since 1998 only
Hadley Center for Climate PredictionHadley Center for Climate Prediction——largest largest precipitous change ever measured, up or downprecipitous change ever measured, up or downp p g , pp p g , p
SatelliteSatellite--measured monthly globally averaged measured monthly globally averaged lower atmospheric temperature variationslower atmospheric temperature variationsp pp p
30
Hurricane Frequency
25
30
Are hurricanes increasing?
Is there a natural cause?
20
d St
orm
s
s e e u c use?
15
ber
of N
amed
5
10Num
0
5
197619771978197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005
Year
Lots of FEMA trailors!Lots of FEMA trailors!
The history of theThe history of the Atlantic Multidecadal OscillationAtlantic Multidecadal Oscillation (AMO)(AMO)Index shows that positive and negative phases typically last Index shows that positive and negative phases typically last forfor 20 to 40 years20 to 40 years.. Since 1994, the AMO index has been Since 1994, the AMO index has been positive, indicating that the United States might be headed positive, indicating that the United States might be headed into a prolonged period of increased hurricane activityinto a prolonged period of increased hurricane activityinto a prolonged period of increased hurricane activity.into a prolonged period of increased hurricane activity.
Regional variationRegional variation----Redneck hot tub!Redneck hot tub!
Greensburg, KS EFGreensburg, KS EF--5 5 May 2007May 2007
Tornadoes Reported Per Year
2000 350
1600
1800
2000
300
350
1200
1400
1600
nado
es
200
250
illio
ns)
Population Population growthgrowth
800
1000
ber o
f Tor
n
150
200
Popu
latio
n (m
400
600Num
0
100 U.S.
P
Reported Reported t dt d
0
200
0
50tornadoestornadoes
1950
1953
1956
1959
1962
1965
1968
1971
1974
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
Year
Atmospheric CirculationAtmospheric Circulation----Normal ConditionsNormal Conditions
Atmospheric CirculationAtmospheric Circulation----El Nino ConditionsEl Nino Conditions
Light at the end of the tunnelLight at the end of the tunnel
Climate ChangeClimate Change——Increased Increased impacts on a more populous Earthimpacts on a more populous Earthimpacts on a more populous Earthimpacts on a more populous Earth
•• Atlanta water supply 2007Atlanta water supply 2007——distributiondistribution•• Atlanta water supply 2007Atlanta water supply 2007——distribution distribution problem?problem?–– 9 million in GA9 million in GA9 million in GA9 million in GA–– 7 million in north GA7 million in north GA–– 5 million in Atlanta!! 5 million in Atlanta!!
•• MS Delta aquiferMS Delta aquifer——water volume declinewater volume decline–– Much more irrigation nowMuch more irrigation now–– Drought increases demand, multiplies impact Drought increases demand, multiplies impact
ControversyControversy CautionCautionControversyControversy----CautionCaution
•• Scientific polarizationScientific polarization•• Political/policy confusionPolitical/policy confusionPolitical/policy confusionPolitical/policy confusion•• Firing 3 State ClimatologistsFiring 3 State Climatologists•• Alarmism “snake oil salesmen”Alarmism “snake oil salesmen”•• Alarmism, “snake oil salesmen”Alarmism, “snake oil salesmen”