The impact of global warming in Antarctica

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The impacts of warming temperatures in Antarctica are likely to occur first in the northern sections of the continent, where summer temperatures approach the melting point of water, 32°F (0°C). Some ice shelves in the northernmost part of Antarctica—the Antarctic Peninsula—have been collapsing in recent years, consistent with the rapid warming trend there since 1945. Scientists are also concerned about future changes in the large West Antarctic ice sheet on the main continent because its collapse could raise sea level by as much as 19 feet (5.8 meters).

Fingerprints

70. Antarctic Peninsula -- Warming 5 times global average. Since 1945, the Antarctic Peninsula has experienced a warming of about 4.5°F (2.5°C). The annual melt season has increased by 2 to 3 weeks in just the past 20 years.

73. Antarctica -- Ice shelf disintegration. The 770 square mile (1,994 km²) Larsen A ice shelf disintegrated suddenly in January 1995.

74. Antarctica -- Ice shelf breakup. After 400 years of relative stability, nearly 1,150 square miles (2,978 km²) of the Larson B and Wilkins ice shelves collapsed between March 1998 and March 1999.

122. Southern Ocean - Strong warming trend. Measurements from data recorders in the Southern Ocean waters around Antarctica show a 0.3°F (0.17°C) rise in ocean temperatures between the 1950s and the 1980s.

140. Antarctica - Decreasing Ice-thickness. The permanent ice cover of nine lakes on Signey Island has decreased by about 45% since the 1950s. Average summer air temperature has warmed by 1.8°F (1°C).

141. Antarctic Peninsula - Collapsing ice-shelf, January-February 2002. The northern section of the Larsen B ice shelf, an area of 1,250 square miles (3,250 km²), disintegrated in a period of 35 days. This was the largest collapse event of the last 30 years, bringing the total loss of ice extent from seven ice shelves to 6,760 square miles (17,500 km²) since 1974. The ice retreat is attributed to the region’s strong warming trend - 4.5°F (2.5°C) in the last 50 years.

Harbingers

32. Antarctica -- Penguin population decline. Adelie Penguin populations have shrunk by 33% during the past 25 years in response to declines in their winter sea ice habitat.