Global Warming 56 Million Years Ago & What it Means

46 Pages·2016·9.44 MB·English

by  Scott Wing

Global Warming 56 Million Years
Ago & What it Means for Us
Scott Wing
Dept. of Paleobiology
Smithsonian Institution Museum of Natural History
© Ira Block
Anthropogenic increase in CO
2
11000000(cid:9)(cid:9)

)
m 2100 – business as usual
2100 – business as usual
p 990000(cid:9)(cid:9)
p
(

e 880000(cid:9)(cid:9)
r
e
h
p 770000(cid:9)(cid:9)
s
o
m 660000(cid:9)(cid:9)
t
a

n 550000(cid:9)(cid:9)
i

n
o 440000(cid:9)(cid:9) 2014 2014
i
t
a
r
330000(cid:9)(cid:9)
t
n
e
c
220000(cid:9)(cid:9)
n
o
c
110000(cid:9)(cid:9)
2
O
C
00(cid:9)(cid:9)
-8110 000000(cid:9)0(cid:9)11-0700(cid:9)0010200(cid:9)0(cid:9)-610300000(cid:9)0(cid:9)14-0500(cid:9)0010500(cid:9)0(cid:9)-410600000(cid:9)0(cid:9)17-0300(cid:9)0010800(cid:9)0(cid:9)-210900000(cid:9)0(cid:9)20-10000(cid:9)020100(cid:9)0(cid:9) 2200(cid:9)0(cid:9)
Years ago
Data from NOAA-NCDC
Inferred pCO
2
2100
BAU
2015
Pre-
industrial
IPCC 2013 AR5, from Beerling & Royer 2011
Paleogeography
56 million years ago
Estimated Global Mean Temperature
(difference from present)

)
t
n
Antarctic Ice Sheets
12
e
s
e

r
Arctic Ice Sheets
p
>
8

C
°

(

p
m 4
e “Eocene” Climate Enigma
t

l
a
b 0
o
l
G
60 50 40 30 20 10 0
Millions of years ago
modified from Hansen & Sato 2011, data from Zachos et al. 2008
The Eocene climate enigma
Warm poles
Dawn Redwood forest
Axel Heiberg Island, Canada
D. Greenwood photo
© Ira Block
The Eocene climate enigma
Warm winters
palm leaf, Wyoming, USA
Field Museum
© Ira Block
Estimated Global Mean Temperature
Paleocene-Eocene
(difference from present)
Thermal Maximum
(PETM)

)
t
n
Antarctic Ice Sheets
12
e
s
e

r
Arctic Ice Sheets
p
>
8

C
°

(

p
m 4
e “Eocene” Climate Enigma
t

l
a
b 0
o
l
G
60 50 40 30 20 10 0
Millions of years ago
modified from Hansen & Sato 2011, data from Zachos et al. 2008