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| q |
We have learned that the dominant cycle of
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ice sheet variations over the last several
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hundred years has also been 100,000 years.
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| q |
This suggests that the 100,000-year
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variations in atmospheric CO2 match those
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of ice sheets.
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| q |
Over the 400,000-year length of the ice
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core record, the major cycles of CO2
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change line up well with the ice volume
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changes (indicated by d18O).
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| q |
The two signals share not only the 100,000-
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year cycle but also its asymmetric shape:
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abrupt increases in CO2 during times of
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rapid ice melting (i.e., warming) and slower
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decreases during times of slower phases of
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ice volume buildup (cooling).
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| q |
WHY?
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