91
ANTARCTICA
5.4 MILLION SQ. MILES
CONTIGUOUSU.S.
3.1 MILLION SQ. MILES
Summer ice
Winter ice
GIGATONNES
SINCE 1992
MM
TOTAL
SEA LEVEL
RISE
CUMULATIVE
CHANGE IN
ICE MASS
From
thermal
expansion
From
added
water
1993 2000 ’05 ’10 ’15 2017
1992 ’95
-3,000
-2,000
-1,000
0
1,000
2000 ’05 ’10 ’15 ’17
0
20
60
80
Continental imbalance
Antarctica’s ice grows and shrinks
seasonally. But, particularly in
western regions, ice is melting faster
than it is accumulating
Behind earth’s rising seas
THE EXTENT
Antarctica’s
area roughly
doubles each
winter from
coastal sea
ice
SWELLING WATERS
Carbon dioxide traps
heat, which melts
polar ice and raises
ocean temperatures.
Water expands as it
warms, further raising
sea levels
WHAT’S MELTING
Seas may rise 1 m in
100 years. Antarctica is
melting slower than the
Arctic, but it has more
ice. Here are sea-level
gains if all the glaciers
melted
THE LOSSES
Antarctic ice melt has accelerated.
The rate of recent ice loss is five
times the rate of 20 years ago
THE DEPTH
The deepest ice
is 3 miles thick,
the height of
11 Empire
State Buildings
73 m
Antarctica’s
glaciers
6 m
Greenland’s
glaciers
0.6 m
Nonpolar
glaciers
0.12 m
Alaska’s
glaciers
49 gigatonnes
of ice shed annually
from 1992 to 1997
219 gigatonnes
of ice shed annually
from 2012 to 2017
Collapse
The ice shelves
break apart.
This does
not raise sea
levels, as the
ice was already
in the water
Acceleration
But with no
resistance from
the ice shelf,
glacier ice flows
faster, falls
into the ocean
and raises sea
3
4
Ð2,324
gigatonnes