The Arctic &
Global Climate Change
Robert D. Hollister
Outline
The Arctic
Changing Cryosphere
Tundra Ecology
Predicted Change
Observed Change
My Research
Politics
The Arctic
Arctic Circle
Lat. 62.50N
24 hr Day
24 hr Night
Treeline
500F/100C
10 oC July isotherm
Arctic Watershed
Changing Cryosphere
IPCC (Intergovernmental Panel on Climate Change) 2007.
% change
Changing Sea Ice Coverage in
September (satellite images)
1979
2003
Summer minimum Arctic Sea Ice
8.9% loss per decade
United Nations Environment Programme (2007) Global Environment Outlook GEO-4 Report
1979
2003
Global Glacier Change
Mass Change
Effect on Sea Level
Dyurgerov & Meier, 2005
Glacial Melt in Greenland
Hansen, Scientific American, March 2004
The Global Role of Snow
NASA animation showing positive feedback
As the snow melts more solar radiation is absorbed and more snow melts
Tundra Ecology
Why Study The Arctic?
Why Study The Arctic?
• Less complex
“simple food web”
fewer species
fewer interactions
Why Study The Arctic?
• Less complex
• Expected to change greatly
due to warming
90N
Predicted ANNUAL Temperature Increase in 2100
my site
60
30
0
30
60
90S
180
120W
-1
0
60W
1
2
0
3
4
60E
5
6
120E
8
10
180
12
oC
IPCC (Intergovernmental Panel on Climate Change) 2001.
Climate Change 2001: The Scientific Basis
Why Study The Arctic?
• Less complex
• Expected to change greatly
due to warming
• The “canary in the coal mine”
I’m dying,
Run for your
life!!!
Permafrost –the frozen ground
Distribution of Permafrost
Distribution of Permafrost
Projected loss of 60-90% by 2100
Drunken Forest
Damaged Buildings
Anisimov & Reneva (2006) Ambio:35:169-175
Loss of Lakes and Ponds In Alaska
Copper River Basin 1985
Copper River Basin 1995
Lake Disappearance in Russia
Smith et al. (2005) Science 308:1429
Catchment Area
Will discharge change
due to changes in
permafrost?
numbers are cubic kilometers of discharge
CAFF (Conservation of Arctic Flora and Fauna) 2001.
Arctic Flora and Fauna: Status and Conservation.
Helsinki: Edita. 272 p.
Carbon rich ground
Seasonal Active Layer
Carbon Store
C.E. Tweedie
Carbon rich ground
Seasonal Active Layer
Carbon Store
Vulnerable:
350-900 Gigatonnes
Current atmosphere:
750 Gigatonnes
C.E. Tweedie
Carbon rich ground
Seasonal Active Layer
Carbon Store
Vulnerable:
350-900 Gigatonnes
Current atmosphere:
750 Gigatonnes
1% loss would equal current rate of emissions
C.E. Tweedie
Measuring carbon balance
CO2 Flux
Measuring carbon balance
CO2 Flux
In saturated soils CH4 is generally more
important than CO2 Flux
C.E. Tweedie
Methane tends to be released in pulses
Burning a methane bubble
Predicted Change
Behavior change
No behavior change
IPCC (Intergovernmental Panel on Climate Change) 2007.
Observed annual temperature trend 1901 to 2005
IPCC (Intergovernmental Panel on Climate Change) 2007.
Temperature Trends
Distribution of the major terrestrial biomes
Campbell Biology 4th Edition
Mean Annual Temperature (C°)
Location of principal biomes in climate space
Mean Annual Precipitation (cm)
high
Temperature gradients
rock, snow, ice
tundra
low
Altitude
coniferous forest
deciduous forest
tropical forest
equatorial
Latitude
polar
Townsend Harper Begon; Essentials of Ecology
high
Temperature gradients
rock, snow, ice
low
Altitude
tundra
Adiabatic lapse rate
1oC ~ 100 m
coniferous forest
deciduous forest
1oC ~ 150 km
tropical forest
equatorial
Latitude
polar
Townsend Harper Begon; Essentials of Ecology
Biome Shifts “Over-the-top hypothesis”
Tundra
Current biomes
?
Climate
Warming
Future biomes
Today
Future projection
2 x CO2
(2025)
(Emanuel et al. 1985)
IPCC (Intergovernmental Panel on Climate Change) 2007.
Annual Pattern of Environmental Variables and
o
Photosynthesis for Barrow (71 N), Alaska
MJcm-2d-1
40x102
20x102
0
Mean solar radiation
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
1 - Temperatures are cold and overlap freezing
MJcm-2d-1
40x102
20x102
0
Mean solar radiation
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
2 - Short growing season
MJcm-2d-1
40x102
20x102
0
Mean solar radiation
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
3 – Thin active layer
MJcm-2d-1
40x102
20x102
0
Mean solar radiation
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
4 – Declining solar radiation
MJcm-2d-1
40x102
20x102
0
Mean solar radiation
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
Warming Will:
MJcm-2d-1
40x102
20x102
0
1 Push temperatures beyond freezing
2 Longer growing season
3 More nutrients available
Mean solar radiation
4 More solar radiation available
Radiation absorbed
by plants
cm
Snow depth
40
20
0
oC
-20
-40 10
0
-10
-20
-30
J
F
M
Snow depth
Depth of thaw
Air temperature range
A
M
J
J
A
S
O
N
D
Month
(Chapin and Shaver 1985)
Observed Change
Greening trend (NDVI) 1982-91
Spring temp. trend 1982-90
(Myneni et al. 1997)
Forest growth in northern Sweden
1906
1986
temperature has
increased but land use
has also changed
Arctic Report Card 2007
Shrub expansion
Alaska 1949 – 2001
(Sturm et al. 2001)
Summary of Observed Tree and Shrub Expansion
Arctic Report Card 2007
Summary of Observed Tree and Shrub Expansion
Arctic Report Card 2007
Summary of Observed Tree and Shrub Expansion
Arctic Report Card 2007
Influence of vegetation
Increased absorbed radiation
Denser
Plant
Layer
deeper thaw
frozen soil
shallower thaw
frozen soil
It is estimated that shrub and tree
expansion may magnify regional
warming by a factor of 2-7
IPCC (Intergovernmental Panel on Climate Change) 2007.
My Research
Barrow
Atqasuk
Data Collection
• Abiotic
• Plant
• Community
• Ecosystem
500
Warmed
Warmed
Control
Control
400
Chambers caused
significant increases in
Thawing degree-days
over the summer
350
300
250
200
150
100
50
18-Aug
10-Aug
2-Aug
25-Jul
17-Jul
9-Jul
1-Jul
23-Jun
15-Jun
0
7-Jun
Thawing degree-days (TDDsm)
450
Hollister & Webber 2000. Global Change Biology 11:525-536
500
ra
tu
Control
Control
te
m
pe
400
Chambers caused
significant increases in
Thawing degree-days
over the summer
an
d
350
tim
e
300
ra
te
s
250
In
te
g
200
150
100
50
18-Aug
10-Aug
2-Aug
25-Jul
17-Jul
9-Jul
1-Jul
23-Jun
15-Jun
0
7-Jun
Thawing degree-days (TDDsm)
re
Warmed
Warmed
450
Hollister & Webber 2000. Global Change Biology 11:525-536
Length of inflorescence
Luzula confusa
Inflorescence length (cm)
25
Symbol - site
AD
AW
BD
BW
Line - year
1998
1999
2000
Fill/Color - treatment
control
warmed
Luzula confusa
20
15
10
5
0
160
180
200
Julian day (day of the year)
220
cm
Inflorescence length (cm)
Inflorescence length (cm)
25
Symbol - site
AD
AW
BD
BW
Line - year
1998
1999
2000
Fill/Color - treatment
control
warmed
Luzula confusa
20
15
10
5
0
160
180
200
Julian day (day of the year)
220
25
20
cm
15
10
5
0
0
200
400
600
TDDsm (Time and Temperature)
Hollister et al. 2005. Ecology 86:1562-1570
Increased flowering
Community Changes
Walker, Wahren, Hollister et al. 2006. PNAS 103:1342-1346
Summary Diagram
Control
Warmed
Key
forb
short graminoid
lichen
bryophyte
erect shrub
tall graminoid
Key
Control
forb
short graminoid
Warmed
lichen
bryophyte
erect shrub
tall graminoid
Hollister 2003. PhD Thesis
A general increase in canopy height due to:
• an increase in stature of previously existing species
• a shift in composition from lichens and bryophytes
toward shrubs and graminoids
Barrow
wet
dry
Atqasuk
wet
dry
Ecosystem Measures
Net Ecosystem Exchange
(NEE) of carbon
control
warmed
Oberbauer et al. 2007. Ecological Monographs 77:221-238
Summary of changes in tundra
• Increased biomass (denser, bigger individuals,
more shrubs and tall grasses)
– increased solar absorption
– changing thaw depth
•
•
•
•
Increased absorbed radiation
Changing species interactions
Loss of biodiversity
Changing permafrost
Release of carbon
C
Denser
Taller
Plant
Layer
Fewer
Species
changing thaw
frozen soil
Summary of changes in tundra
• Increased biomass (denser, bigger individuals,
more shrubs and tall grasses)
2-7X2-7
warmer
X –
regional
warming –
•
•
•
•
increased solar absorption
changing thaw depth
Increased absorbed radiation
Changing species interactions
Loss of biodiversity
Changing permafrost
Release of carbon
C
Potentially as much as
Fossil Fuel Burning
Denser
Taller
Plant
Layer
Fewer
Species
changing thaw
frozen soil
Behavior change
No behavior change
IPCC (Intergovernmental Panel on Climate Change) 2007.
Politics
Bush
Clinton
Bush
Al Gore
Understanding the issue
Katrina
Why we should care
Its gettin hot!
The Arctic
The singing canary
Important Point
IPCC (Intergovernmental Panel on Climate Change) 2001.
Climate Change 2001: The Scientific Basis
IPCC (Intergovernmental Panel on Climate Change) 2001.
Climate Change 2001: The Scientific Basis
IPCC (Intergovernmental Panel on Climate Change) 2001.
Climate Change 2001: The Scientific Basis
Stern Report 2006
Stern Report published in 2006
Commissioned by the British Government
Using the results from formal economic models, the Review
estimates that if we don’t act, the overall costs and risks of
climate change will be equivalent to losing at least 5% of
global GDP each year, now and forever. If a wider range of
risks and impacts is taken into account, the estimates of
damage could rise to 20% of GDP or more.
In contrast, the costs of action – reducing greenhouse gas
emissions to avoid the worst impacts of climate change –
can be limited to around 1% of global GDP each year.
Questions….
C.E. Tweedie
Further Information:
The GVSU Arctic Ecology Program
http://faculty.gvsu.edu/hollistr/
Arctic Report Card
http://www.arctic.noaa.gov/reportcard/
IPCC 2007
http://www.ipcc.ch/
Arctic Climate Impact Assessment (ACIA)
http://www.acia.uaf.edu/
Articles in the Journal Nature
The new face of the Arctic Nature 8 March 2007 466:133-135
A world melting from the top down Nature 12 April 2007 466:718-721