Global Outlook for Ice & Snow
isphere latitudes 3,4 . Palaeo data from corals indicate that sea level was 4 to 6m(ormore) above present day sea levels during the last interglacial period, about 125000years ago 5 . Climate and ice-sheet model simulations 6 indicate that Greenland was about 3° C warmer than today and that the Northern Hemisphere ice sheets contributed 2.2 to 3.4 m to the higher sea level, with the majority of the rise com- ing from the partial melting of the Greenland ice sheet.
have the largest potential to contribute to significant changes in sea level.
Past sea-level change
Ice-age cycles and sea level
Sea level varied over 100 m during glacial–interglacial cy- cles as the major ice sheets waxed and waned as a result of changes in summer solar radiation in high northern hem-
During the last ice age, sea level fell to more than 120 m below present day sea level as water was stored in the
Global mean Sea Level (cm)
+20
+10
0
Tide gauge observations (with 66 and 95% confidence limits) Satellite altimeter observations
-10
2000
1880
1900
1920
1940
1960
1980
Figure 6C.3: Global averaged sea levels from 1870 to 2006 as inferred from tide-gauge data (white line, with 66% and 95% confi- dence limits given in dark and light shading) and satellite altimeter data (red line). Source: Updated from Church and White 2006 13
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GLOBAL OUTLOOK FOR ICE AND SNOW
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