 |
|
|
|
|
|
|
|
|
|
|
|
| q |
The longest orbital-scale record of CO2
|
|
|
|
changes comes from the Vostok ice core
|
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|
drilling site.
|
|
|
| q |
The CO2 record shows a series of regular
|
|
|
oscillation between CO2 values as high as
|
|
280-300 ppm and as low as 180-190 ppm
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|
over the last 400,000 years.
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|
|
| q |
Values at the high end of this range occur
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|
within the present interglacial interval.
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|
|
| q |
These relative high CO2 values lasted for
|
|
|
|
several thousand years before the abrupt
|
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|
increase after 1800.
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|
| q |
The dominant period of CO2 variations is
|
|
|
about 100,000 years.
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|
