global warming 56 million years ago & what it means for us · global warming 56 million years...
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![Page 1: Global Warming 56 Million Years Ago & What it Means for Us · Global Warming 56 Million Years Ago & What it Means for Us. Scott Wing . Dept. of Paleobiology . Smithsonian Institution](https://reader030.vdocuments.site/reader030/viewer/2022040719/5e29cf43bb0be9232151690b/html5/thumbnails/1.jpg)
© Ira Block
Global Warming 56 Million Years Ago & What it Means for Us
Scott Wing Dept. of Paleobiology Smithsonian Institution Museum of Natural History
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0
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-800000 -700000 -600000 -500000 -400000 -300000 -200000 -100000 0
CO
2 c
on
cen
trat
ion
in a
tmo
sph
ere
(pp
m)
Years ago
2100 – business as usual
2014
Anthropogenic increase in CO2
Data from NOAA-NCDC
0
100
200
300
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600
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1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200
2100 – business as usual
2014
1
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Inferred pCO2
IPCC 2013 AR5, from Beerling & Royer 2011
Pre- industrial
2015
2100 BAU
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Paleogeography 56 million years ago
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Estimated Global Mean Temperature (difference from present)
Millions of years ago 60 50 40 30 20 10 0
12
8
4
0
Glo
bal
tem
p (
°C >
pre
sen
t)
Antarctic Ice Sheets
Arctic Ice Sheets
modified from Hansen & Sato 2011, data from Zachos et al. 2008
“Eocene” Climate Enigma
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The Eocene climate enigma Warm poles
Dawn Redwood forest Axel Heiberg Island, Canada
D. Greenwood photo
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© Ira Block
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The Eocene climate enigma
Field Museum
Warm winters palm leaf, Wyoming, USA
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© Ira Block
![Page 10: Global Warming 56 Million Years Ago & What it Means for Us · Global Warming 56 Million Years Ago & What it Means for Us. Scott Wing . Dept. of Paleobiology . Smithsonian Institution](https://reader030.vdocuments.site/reader030/viewer/2022040719/5e29cf43bb0be9232151690b/html5/thumbnails/10.jpg)
Millions of years ago 60 50 40 30 20 10 0
12
8
4
0
Glo
bal
tem
p (
°C >
pre
sen
t)
Antarctic Ice Sheets
Arctic Ice Sheets
modified from Hansen & Sato 2011, data from Zachos et al. 2008
Paleocene-Eocene Thermal Maximum
(PETM)
“Eocene” Climate Enigma
Estimated Global Mean Temperature (difference from present)
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PETM carbon & temperature
Murphy et al. 2010
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http://www-odp.tamu.edu/publications/208_IR/208ir.htm
Dissolution of deep ocean chalk
Zachos et al (2005)
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Paleocene-Eocene Thermal Maximum (PETM)
• Global warming of 4 to 8 °C
• Extensive marine carbonate dissolution
• Carbon isotope ratio shift of -4‰ to -5‰
• Total duration >100 ky
CONCLUSION
Release of 4,000-7,000 Pg of carbon in a few millennia or less
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Potential carbon sources
Methane Hydrates
Thermogenic Methane
Wikipedia
Wildfire
Permafrost
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P-E boundary records
Paleogeography by C.R. Scotese, PALEOMAP Project
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Google Earth Tom Nash photo
The Bighorn Basin
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Tom Nash photo
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50 km
Bighorn Basin, Wyoming, Fossil Plant Sites
225 Sites 314 Taxa
1 km strata 7 million yr
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Bighorn Basin Plant Fossil Sites
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Millions of Years Before Present
Cu
mu
lative
# F
ossil
Pla
nt
Site
s
P
E
T
M
+ = one leaf fossil site
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Body
of
CIE
Recovery
![Page 20: Global Warming 56 Million Years Ago & What it Means for Us · Global Warming 56 Million Years Ago & What it Means for Us. Scott Wing . Dept. of Paleobiology . Smithsonian Institution](https://reader030.vdocuments.site/reader030/viewer/2022040719/5e29cf43bb0be9232151690b/html5/thumbnails/20.jpg)
Floral Change during the PETM
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20
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120
-56.0 -55.9 -55.8 -55.7 -55.6 -55.5 -55.4 -55.3 -55.2 -55.1 -55.0
Body CIE
Millions of Years Before Present
Pla
nt
Spec
ies
Tim
e R
ange
s
Recovery
Possible extinctions
PETM-only immigrants
Eocene
Local Extirpations
! "
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() %*! " () ) *+" () ) *&" () ) *, " () ) *%" () ) *) " () ) *$" () ) *- " () ) *#" () ) *' "-56.2 -56.1
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Possible Extinctions
Davidia antiqua
Dogwood family
Browniea serrata
Dogwood order
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PETM-only, bean family
1.
2.
3. 4.
5.
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Post-PETM Immigrants
Alder
Climbing fern
Hickory family Linden family
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Sycamore Birch family
Dawn redwood
Ginkgo
Sycamore
Locally extirpated
Katsura tree Oak family
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PETM plant geographic change
56 Ma
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Floristic Change in Wyoming
1. PETM onset - local/regional EXTIRPATION of temperate deciduous plants (dawn redwood, birch, sycamore, katsura), and immigration of bean family and other dry tropical plants
2. PETM recovery - local/regional EXTIRPATION of bean family et al., return of “natives”, and intercontinental immigration of temperate plants
3. Minor EXTINCTION (~10%)
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Aldo Chiappe for National Geographic
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PETM – abundant insect damage
© Ira Block © Ira Block
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Hyracotherium - Perissodactyla
Primates PETM faunal interchange
Diacodexis - Artiodactyla C. Clark photo
C. Clark photo
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Horse body size decrease during PETM
Tom Nash photo
(Secord et al. 2012)
© Ira Block
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Four lessons from the PETM
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1. A big release of carbon warmed global climate and dissolved deep marine chalk
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2. There was probably positive feedback – carbon release increased temperature, releasing more carbon
Geological Release of CO2 and/or methane
Wildfires
Deep ocean CH4 dissociation
Atmosphere warms
Intermittent rainfall
CH4 CO2
Ocean warms
CO
2
CH
4
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3. Rapid global warming changed where plants & animals lived, how they interacted, and drove rapid evolution
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4. The effects lasted about 200,000 years
Murphy et al. 2010
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Taking the Long View
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Carbon uptake is very slow
IPCC 5th Assessment Chapter 6 after Archer et al. 2009
5,000 billon tons of carbon into atmosphere (the whole enchilada)
Original CO2 level Bill
ion
s o
f to
ns
of
carb
on
15-40% remains after 10,000 years }
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5
4
3
2
1
0
Surf
ace
War
min
g (
C)
1800 2000 2200 2400 2600 2800 3000 Year (CE)
Assumptions:
Carbon emissions ~7 Gt/yr
Emissions increase at ~2%/yr
We burn it all - ~5,000 Gt
Solomon et al. (2009) PNAS
Temperature stays high
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1 10 1,000 100 10,000 100,000
-Ho
use
ter
m-
-IP
CC
pro
ject
ion
s-
SOC
IAL-
PO
LITI
CA
L-EC
ON
OM
IC
ECO
LOG
ICA
L-EV
OLU
TIO
NA
RY
natural continent-scale dispersal
rapid evolution (2X body size)
EAR
TH S
YSTE
M
CO2 uptake via
weathering
CO2 surface ocean invasion
CO2 deep ocean mixing
ice sheet response
Evolutionary diversification
$1
bill
ion
$
1 a
t -3
%
-fo
ssil
fuel
s g
on
e?-
-avg
hu
ma
n li
fesp
an
-
-Ja
pa
nes
e m
on
arc
hy-
DURATION IN YEARS (log scale)
-Pre
sid
enti
al t
erm
- -S
ena
te t
erm
-
-avg
. Su
pre
me
Co
urt
-
-Ch
rist
ian
ity-
forest maturation
glacial cycles
-ho
me
mo
rtg
ag
e-
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Sea level +7.5m (~25ft) – 5000 CE? (whoops! Greenland Ice Cap melted)
Nickolay Lamm StorageFront.com
NYT Sunday Review November 24, 2012 Data from Climate Central
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Ginkgo adiantoides 57 million years old
Ginkgo biloba a “living fossil”
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Ginkgo leaf surface
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4
5
6
7
8
9
10
11
12
13
14
250 350 450 550 650 750 850
Sto
ma
tal In
de
x (
%)
CO2 (ppm)
error bars = 1s
Stomatal Index vs. pCO2 in Ginkgo biloba
Barclay & Wing in prep
y = 110.18x-0.426
R² = 0.60
y = -0.011x + 12.96
R² = 0.58
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Ginkgo adiantoides 56.1 million year old “mummified” leaf
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8
10
12
14
16
18
20
0
100
200
300
400
500
600
700
800
900
1,000
-56.8 -56.6 -56.4 -56.2 -56.0 -55.8 -55.6
CO
2(p
pm
)
Time (Ma)
+341
+258
PETM
Temperature increase of ~5 °C from mammal tooth isotopes (Secord et al. 2010)
Temperature increase of ~4 °C from leaf physiognomy
(Currano et al., 2010)
0
100
200
300
400
500
600
700
-56.8 -56.6 -56.4 -56.2 -56.0 -55.8 -55.6
CO
2(p
pm
)
Time (Ma)
+341
+258
0
100
200
300
400
500
600
700
-56.8 -56.6 -56.4 -56.2 -56.0 -55.8 -55.6
CO
2(p
pm
)
Time (Ma)
+341
+258
0
100
200
300
400
500
600
700
800
900
1,000
-56.8 -56.6 -56.4 -56.2 -56.0 -55.8 -55.6
CO
2(p
pm
)
Time (Ma)
+341
+258
+468
8
10
12
14
16
18
20
0
100
200
300
400
500
600
700
800
900
1,000
-56.8 -56.6 -56.4 -56.2 -56.0 -55.8 -55.6
CO
2(p
pm
)
Time (Ma)
+341
+258
MAT
(C
)
Barclay & Wing in prep
CO2 doubles and temperature increases 4-5° C