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Line 17: − − The stable upper atmospheric (stratospheric) air mass over the continent has been seriously altered by synthetic chemicals that arrived via natural atmospheric circulation from the world's industrial areas, resulting in the creation of the well-known Antarctic ozone hole. Ice core records provide evidence that atmospheric greenhouse gases such as carbon dioxide and methane have increased markedly during the past 200 years and are presently more prevalent than at any time in the past 160,000 years. These records also show that low temperatures of the ice age occurred when greenhouse-gas concentrations were low.
→Antarctic Environment: Move global warming controversy stuff to talk
Offshore cyclones occur with little warning. Winds typically reach hurricane strength within an hour and persist for several days. A concentration of storm formation and/or intensification occurs at approximately 50°S latitude and is associated with some of the most violent seas in the world ("the roaring forties"). The stretch of ocean between Antarctica and the tip of South America is considered the most hostile in the world and has claimed numerous ships over the centuries.
Offshore cyclones occur with little warning. Winds typically reach hurricane strength within an hour and persist for several days. A concentration of storm formation and/or intensification occurs at approximately 50°S latitude and is associated with some of the most violent seas in the world ("the roaring forties"). The stretch of ocean between Antarctica and the tip of South America is considered the most hostile in the world and has claimed numerous ships over the centuries.
Meteorological observations have been recorded only in recent decades, and then only in scattered localities, so long-term temperature trends remain uncertain. The longest instrumental temperature records come from the relatively warm Antarctic Peninsula region, referred to by the "Frozen Chosen" as the "Banana Belt" of Antarctica. The glacial systems that occur in the Peninsular region are the most delicate in Antarctica and the most vulnerable to climatic warming. In historical time the fronts of the Larsen and George VI ice shelves, the two largest ice shelves in the region, have retreated at rates of nearly one-half mile per year. Another smaller ice shelf, the Wordie Ice Shelf, has completely vanished during the past several decades. Whether these changes are due to induced global warming or to natural (perhaps regional) climatic cycles remains uncertain.
Meteorological observations have been recorded only in recent decades, and then only in scattered localities, so long-term temperature trends remain uncertain. The longest instrumental temperature records come from the relatively warm Antarctic Peninsula region, referred to by the "Frozen Chosen" as the "Banana Belt" of Antarctica. The glacial systems that occur in the Peninsular region are the most delicate in Antarctica and the most vulnerable to climatic warming. In historical time the fronts of the Larsen and George VI ice shelves, the two largest ice shelves in the region, have retreated at rates of nearly one-half mile per year. Another smaller ice shelf, the Wordie Ice Shelf, has completely vanished during the past several decades. Whether these changes are due to induced global warming or to natural (perhaps regional) climatic cycles remains uncertain.