662 | Nature | Vol 577 | 30 January 2020
Article
the end of T-I (Fig. 1a, g). Some have attributed the faster rate of sea-level
rise during T-II to the greater boreal summer insolation forcing^3 , but
that forcing only exceeds that of T-I after the majority (~80 m) of T-II
sea-level rise had occurred (Fig. 1a, b, Extended Data Fig. 2). Otherwise,
insolation forcing during the first 8 kyr of each termination is similar
(~55 W m−2), whereas the associated 80 m of sea-level rise during T-II is
much greater than that during T-1 (~35 m).
Given the similar radiative forcing and temperature changes dur-
ing the last two terminations, we attribute this contrast in sea-level
response to the greater subsurface warming during T-II associated with1,0002,0002,0002,0000000(^0) 1,000
1,000
1,000
1,000
2,000
2,000
2,000 −600
−600
NEEM −500
GRIP/GISP
0
0
0
1,00
0
1,000
2,000
2,000
3,000
0
0
0 1,000
1,00 0
1,000
2,000
2,000
3,000
0
100
200300
10 –2 10 –1 100 101 102 103
Surface velocity (m yr–1)
–1,000 01 ,000
Thickness change (m)
abc
d
g
ef
5
0
Sea level (m)
AIS
GrIS
–5
–10
140 135 130
Age (ka)
125 120
WAIS collapse
Fig. 3 | Simulations of the Greenland and Antarctic ice sheets. a, The
Greenland Ice Sheet at the PGM. Shown are the Greenland ice-core sites North
Greenland Eemian Ice Drilling (NEEM), Greenland Ice Core Project (GRIP) and
Greenland Ice Sheet Project (GISP). b, The Greenland Ice Sheet at 116 ka. The
logarithmic colour scale shows the velocity fields and contours on the ice sheet
indicate the surface elevation (m). c, Change in the thickness of the Greenland
Ice Sheet between 116 ka and the present day. Contours on the ice surface and
the colour scale show the thickness change. d, The Antarctic Ice Sheet at the
PGM. e, The Antarctic Ice Sheet at 116 ka. The logarithmic colour scale shows
the velocity fields and contours on the ice sheet indicate the surface elevation
(m). f, Change in the thickness of the Antarctic Ice Sheet between 116 ka and the
present day. Contours on the ice surface and the colour scale show the
thickness change. g, Contributions of the Greenland Ice Sheet (GrIS) and
Antarctic Ice Sheet (AIS) to global mean sea level between 140 ka and 116 ka.
WAIS, West Antarctic Ice Sheet.