A%20century%20of%20climate%20change%20in%20Alaska:%20Models%20vs.%20Reality

1
A century of climate change in AlaskaModels vs.
Reality (based on a true story)
Dr. Richard A. Keen University of Colorado,
Boulder (Emeritus) richard.keen_at_colorado.edu NW
S climate observer, Coal Creek Canyon, CO IPCC
WG-I AR-5 expert reviewer
2
Why Alaska? Alaska (and Colorado) are predicted
to have more warming than any of the other
states 4oC (7oF) by 2100
Alaska
? Colorado
3
Alaska is a Global Warming poster child.
4
Part I RealityData analysis contracted by NPS
(Thanks!) and presented in NPS documents
Monitoring Seasonal and Long Monitoring
Seasonal and Long-term Climate Changes/Extremes
in theCentral Alaska Network (CAKN)Pamela J.
Sousanes, Richard A. Keen, Kelly T. Redmond, and
David B. Simeral
5

• Temperature stations
• 95 NWS co-op stations catalogued with periods of
  record from 1 to 111 years
• 38 in and near Denali
• 50 in and near Wrangell-St. Elias
• 7 in and near Yukon-charley
• 50 stations have records gt 10 years
• Very long term stations, or merged combination of
  stations, yield 9 time series gt88 years.
• Climatic Oath
• First do no harm (to the data)

6
One stations record
7
Nine stations combined. 5-year means reveal
decadal changes but retain 20 independent
samples.
8
Alphabet Soup correlate temperature with some
indices used to describe the climate, from
NOAA/ESRL, to find cause. NP PDO TREND
PNA WP NAO EP/NP NAOJ NOI QBO GAM
SOI AAO AO MJO ESPI ENSO MEI Nino
12 Nino 3 Nino 3.4 Nino 4 BEST TP EOF
SST ONI Nino 12 Nino 3 Nino 3.4 Nino 4
TNI WHWP PWP Tropical Pacific EOF SST
MDR MDRMTROP TNA TSA CO2 WHWP AMO
AMM NTA CAR TSI ASAP PDQ OMG MOJO
GOJO BO
9
Aleutian Low
NP North Pacific index, a measure of the
atmospheric pressure over the North Pacific
Ocean. When the pressure goes down, the Low is
stronger, and Alaska gets warmer southerly winds.
Alaska
10
Temperature and NPWhen pressure goes down,
temperature goes up.NP explains 61 of the
temperature variance (R0.79)
11
The NP is the atmospheric component of the
oceanic PDO(pronounced Pee-Dee-Oh)

• The name means..
• Pacific Decadal Oscillation
• Because its in the Pacific, and the feedback
  loop alternates (Oscillates) every few Decades.
• The last switch to warm Alaska was in 1977.
• It may have switched back to cold Alaska in 2006
  but it takes a decade to be sure.

12
Fig. 2. Tree-ring based NPI reconstruction. (a)
Actual and estimated DecMay NPI for the 190083
calibration period (b) Reconstruction of
DecMay NPI from 16001983 based on North Pacific
tree-ring data. Highlighted phase shifts
identified using intervention analysis
(significant at the 90 confidence limit).
Journal of Climate Volume 18, Issue 24 (December
2005) pp. 52535265 TropicalNorth Pacific
Climate Linkages over the Past Four
CenturiesRosanne DArrigo, Rob Wilson, Clara
Deser, Gregory Wilesd, Edward Cook, Ricardo
Villalba, Alexander Tudhope, Julia Cole, and
Braddock Linsley Tree-Ring Laboratory,
Lamont-Doherty Earth Observatory, Palisades, New
York
PDO/NP cycles are natural, lasting 20 - 66 years,
typically around 30 years.
? Alaska Cold ? Alaska Warm
13
Subtract the NP/PDO effect to see what else is
going on.Not much everything else is a
fraction of a degree.
The Arctic Oscillation AO explains another 5
percent of the variance (66 percent total)
14
CO2 explains 4 percent of the residual, or 1
percent of the total variance about 0.2 degree
C.
15
Part I Data - Summary so farDecadal
temperature variability is due mostly to NP/PDO
(61 ), with a smaller AO influence.Internal/Nat
ural climate variability rules Alaskan climate
change.Solar, CO2, and other influences are
minimal.Temperature (and Snowfall , too) shows
no sign of a secular trend.
16
Part II ModelsAlaska predicted to warm 4oC by
2100 (IPCC)
Alaska
17
Alaska 4oC warming by 21001oC has already
happened, according to IPCC
WRONG ? WRONG ?
18
IPCC version of Alaskas climate history, decadal
averages courtesy Hadley CRU
19
Compared to actual observed station data.CRU
adds in 1oC of warming
20
Meanwhile, the models show a 1oC warming.What
do the models not show?Hint begins with P
21
Right, PDO! Alaskas climate variations show the
effect of the NP/PDO. The models dont.
? ?
NP/PDO or
22
IPCC report says this about the PDO They
admit that the models underestimate the PDO,
but then say(Paraphrasing)Changes over
the last 50 years exceed model estimates due
to internal variability (PDO) alone, indicating
that anthropogenic changes may already be
underway
23
IPCC changes exceeding the modeled version of
natural changes are due to non-natural AGWEven
though the models underestimate natural
changes.People underestimate the power of
models.Observational evidence is not very
useful.-- John Mitchell, Chief Scientist UK
Met Office IPCC
24
The power of models, indeed.Rolling dice
simulates the PDO better than the IPCCs billion
models.
25
An easy out the Climate has done so-and-so
since 1950, or 1970, while ignoring what it did
before then.
26
Part III The other Hot Spot Colorado.Coal
Creek Canyon co-op station.IPCC 2oF warming
over 30 years.
27
Bumper sticker scienceColorado, and the
rest of the world, hasnt warmed in 12-15 years
(since 1998 or so). IPCC Santer et al. (2011)
To separate human-caused global warming from the
noise of purely natural climate fluctuations,
temperature records must be at least 17 years
long. (but not more than 32 years)
28
OK, how about 28 years? 0.5oF warming, ¼ of
IPCCs guess
29
Is 160 years enough?Colorado ¼-degree warming
since 1849!
30
The overall warming gets even smaller when you
remove those adjustments NCDC added in.
31
Whats it all mean IPCC models (and modelers)
predict drastic warming for Alaska and
Colorado.Alaska and Colorado arent
warming.Observed climate variations are mostly
due to natural/internal variability, e.g., PDO
etc.IPCC models cannot replicate
natural/internal variability, so they cannot
predict the climate.The Warmers Jimmy the
data to make it agree with the models and look
like it is warming.
32
The Fine PrintAnything I might have said that
could sound like an opinion is not necessarily
that of any organization that receives federal
money.
33
I write books, too. About weather.
34
And a PhD thesis about climate change in the
Arctic.Conclusion jet stream winds and storm
tracks are the major factors.