Review article: Earth's ice imbalance
<p>We combine satellite observations and numerical models to show that Earth lost 28 trillion tonnes of ice between 1994 and 2017. Arctic sea ice (7.6 trillion tonnes), Antarctic ice shelves (6.5 trillion tonnes), mountain glaciers (6.1 trillion tonnes), the Greenland ice sheet (3.8 trillion t...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-01-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/15/233/2021/tc-15-233-2021.pdf |
| Summary: | <p>We combine satellite observations and numerical models to
show that Earth lost 28 trillion tonnes of ice between 1994 and 2017. Arctic
sea ice (7.6 trillion tonnes), Antarctic ice shelves (6.5 trillion tonnes),
mountain glaciers (6.1 trillion tonnes), the Greenland ice sheet (3.8
trillion tonnes), the Antarctic ice sheet (2.5 trillion tonnes), and
Southern Ocean sea ice (0.9 trillion tonnes) have all decreased in mass.
Just over half (58 %) of the ice loss was from the Northern Hemisphere,
and the remainder (42 %) was from the Southern Hemisphere. The rate of
ice loss has risen by 57 % since the 1990s – from 0.8 to 1.2 trillion
tonnes per year – owing to increased losses from mountain glaciers,
Antarctica, Greenland and from Antarctic ice shelves. During the same
period, the loss of grounded ice from the Antarctic and Greenland ice sheets
and mountain glaciers raised the global sea level by 34.6 <span class="inline-formula">±</span> 3.1 mm.
The majority of all ice losses were driven by atmospheric melting (68 %
from Arctic sea ice, mountain glaciers ice shelf calving and ice sheet
surface mass balance), with the remaining losses (32 % from ice sheet
discharge and ice shelf thinning) being driven by oceanic melting.
Altogether, these elements of the cryosphere have taken up 3.2 % of the
global energy imbalance.</p> |
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| ISSN: | 1994-0416 1994-0424 |