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A bipolar perspective on past climate change (and expectations for information from the Third Pole)
Valérie Masson-DelmotteLaboratoire des Sciences du Climat et de l’Environnement
(CEA-CNRS-UVSQ/IPSL)Gif-sur-Yvette, France
3rd TPE Workshop, Reykjavik, Iceland – August 2011
Why study past climate change?
Huybers and Curry, Nature, 2006
• Expand the short instrumental recordsNatural climate variability« Slow » components: ocean, carbon cycle, ice sheets
• Understand the response of climate to forcingsDetection / attributionClimate feedbacksThresholds
• Natural case studies to benchmark Earth System models
Seasonal cycle
Glacial-interglacial cycles
Ice cores
ICELocal climate
AEROSOLS Regional atmospheric aerosol content:Sea salt, dust, volcanism, solar activity, pollutants…
AIRGlobal atmospheric compositionFirnification processes
Deep polar ice cores
NorthGRIP~ 125 000 yrs EDML : 140 000 yrs EDC : 800 000 yrs
European Project for Ice Coring in Antarctica (EPICA)
NEEM?
The greening of Greenland
Masson-Delmotte et al, submitted; updates from Bhatt et al, 2010 and van den Broeke et al, 2009
Greenland ice sheet mass balance
20°C
a)
b)
c)
+2.5°C/century
+4.7°C/century
Saqqaq
Independence I
Early Dorset
Independence II
Late Dorset
Norse
Thule
8
4
0
-4
Gre
enla
nd (°
C)
-8000 -6000 -4000 -2000 0 2000years A.D.
-44
-40
-36
-32
18O
(°/
oo)
120000 100000 80000 60000 40000 20000 0
years before A.D.2000
500
70°N June insolation (W
/m²)
8
4
0
-4
Greenland
(°C
)
208020402000196019201880
years A.D.
2001-2010
2010
last millennium
last millennium
1961-1990
a)
70°N June insolation NGRIP ice core smoothed NGRIP
stack ice core smoothed stack instrumental data
Year 2010 instrumental data MAR forced by ERA40 MAR forced by ERA-INTERIM MAR forced by ECHAM A1B
Instrumental data
Projections (A1B)
Ice core perspective : the last 10 000 years
Greenland cultures
Orbital forcing
Ice core perspective : the last 125 000 years
Masson-Delmotte et al, submitted; data from NGRIP, Nature 2004 and Vinther et al, Nature, 2009
Past, present and projected changes
126 ka (orbital forcing) 2xCO2
DJF
JJA
ann
Limited analogies between past and future climate change
IPSL climate model
Masson-Delmotte et al, Clim Past, in press
• Comparable magnitude of summer warming and feedbacks at mid to high latitudes north• Major differences in low-high latitude temperature gradients and seasonality
Global impacts of Greenland melt in climate projections
• global sea level
• Atlantic meridional overturning circulation
• negative feedback on Arctic warming
• ITCZ shifts with major impacts on monsoonprecipitation
Masson-Delmotte et al, submitted; simulations from Swingedouw et al, J. Climate, 2009Masson-Delmotte et al, submitted; data from NGRIP, Nature 2004 and Vinther et al, Nature, 2009
EPICA, Nature, 2006; Steffenson et al, Science, 2008; Capron et al, Clim. Past, 2010; Masson-Delmotte et al, PNAS, 2010
The Greenland-Antarctic bipolar seesaw
Full glacial conditions
Glacial inception
Precursors: dust from Chinese deserts, Greenland moisture origin shifts
25242322
obliq
uity2520151050
Age (ky BP)
40x10-3200
-20
pre
cess
ion
-10
-8
-6
Calcite
O
280
240
200
CO
2
16
12
8
4
NA
87-2
2 S
ST
(°C
)
3000200010000
IRD
-45
-40
-35
-30
Gre
enla
nd
600
500
400
300
meth
ane
10
8
6
4
deu
teri
um
exc
ess
-440
-420
-400
-380
D
10
8
6
4
deu
teri
um
exc
ess
140135130125120115
Age (ky BP)
3000200010000
IRD
2625242322
obliq
uity
40x10-3200
-20p
rece
ssio
n
-10
-8
-6
Calcite
O
600
500
400
300
meth
ane
280
240
200
CO
2
-440
-420
-400
-380
D
16
12
8
4OD
P98
0 S
ST
(°C
)-45
-40
-35
-30G
reen
lan
d
Masson-Delmotte et al, PNAS, 2010An Zhisheng et al, Science, 2011
Bipolar seesaw under interglacial conditions?
Antarctica T
Antarctic moisture source
Asian monsoon
Methane
CO2
N. Atlantic SST
Greenland T
Bipolar seesaw
Links between abrupt shifts in Antarctic moisture origin and monsoon
New tools for new challenges Searching for the oldest ice in Antarctica
Jouzel et al Science 2007, Loulergue et al Nature 2008, Lisiecki & Raymo Paleoceano 2005Masson-Delmotte et al, QSR, 2010; Jouzel and Masson-Delmotte, QSR, 2011
50x10-3
40302010
0Ex
centr
icit
y
120010008006004002000
Age (ky BP)
24.5
24.0
23.5
23.0
22.5
Ob
liqu
ity
-40x10-3
-200
2040
Pre
cess
ion 4.5
4.0
3.5
3.0
2.5
Ben
thic O-440
-420
-400
-380
D
280
240
200
CO
2
800700600500400300
CH
4
Present-day
Glacials
Interglacials
+5°C
-9°C
• Cause for the shift between 40 ky to 100 ky climatic cycles ?
• Oldest ice challenge
Towards a tri-polar perspective on climate change
• Links between « northern pull », « southern push » and monsoon
• Sequence of events between tropical,mid latitude and polar atmospheric circulation
• Response of climate to major volcanic eruptions (importance for the decadal predictability of climate)
Chunming Shi et al, Clim. Past, submitted
Towards a tri-polar perspective on climate change
• Exceptional monitoring effort for process-based understanding of the climatic drivers of precipitation isotopic composition
• Unique opportunity for a multi-archive TPE approach for reconstructing past precipitation d18O (ice cores, tree rings, lake sediments, speleothems…)
• Need of data syntheses for benchmarking climate models(CMIP5 includes paleoclimate simulations)
Yao Tandong et al, in preparation