Past Climate Variability and Change in the Arctic and at High Latitudes

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The U.S. Climate Science Program Chapter 5
TOTAL MASS BALANCE (GT YR −1 )
0
–100
–200
H
0.5 mm yr –1 sea-level rise)
–300
1960 1970 1980 1990 2000
YEAR
Figure 5.2. Recently published estimates of the mass balance of the Greenland Ice Sheet through time (modified from Alley et al.,
2007b). A total mass balance of 0 indicates neither growth nor shrinkage, and –180 Gt yr –1 indicates ice-sheet shrinkage contributing
to sea-level rise of 0.5 mm/yr, as indicated. Each box extends from the beginning to the end of the time interval covered by
the estimate; the upper and lower lines indicate the uncertainties in the estimates. A given color is associated with a particular
technique, and the different letters identify different studies. Two estimates have arrows attached, because those authors indicated
that the change is probably larger than shown. The dotted box in the upper right is a frequently cited study that applies only
to the central part of the ice sheet, which is thickening, and misses the faster thinning in the margins. [Reprinted from Annals of
Glaciology by permission of International Glaciological Society.]
B
H
T
R
T
R
Z
J
T
C
H
RL
V
L
R