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| Protection from the elements in such extreme conditions is critical. The choice of clothing and how it is worn can be a matter of life and death. |
Today Antarctica's climate varies from extremely cold and dry on the inland plateau to milder, moister conditions along the coast. The average temperature in winter plunges to -58 °F (-50 °C) while a warm day in summer does not often get above 5 °F (-15 °C). Persistent icy winds make the Antarctic air feel even colder. But it has not always been that way.
Fossil evidence suggests that during the last one billion years, the climate of Antarctica has varied from subtropical to freezing. Major global ice ages have occurred around 940 million years ago (mya), 770 mya, 660 mya, and 300 mya. But about 500 mya Antarctica was in the tropics and at its warmest ever. The lush vegetation that covered the continent slowly turned to coal now embedded in the rocks as the climate changed.
Over the past 20 years there has been increasing concern that the earth is warming up as a result of the greenhouse effect caused by an increase in carbon dioxide and other gases in the atmosphere. Unraveling the geologic and glacial history of Antarctica is not easy but it may provide insight into the causes of ice ages and warming trends.
