Feedback between deglaciation and volcanic emissions of CO2

• Main Authors: Peter Huybers, Charles Langmuir
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: ice core
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.2495; http://www.environment.harvard.edu/docs/faculty_pubs/huybers_feedback.pdf

A global reconstruction of subaerial volcanic activity over the last 40 Kyr shows a pervasive high-latitude increase in volcanism between 12 Ka and 7 Ka that more than doubles global volcanic activity. This increase can be understood as a con-sequence of melt generated in response to deglacial decompression. We estimate that increased volcanism during this 5 Ka period emitted an additional 1000 to 5000 Gt of CO2 into the atmosphere. Such a flux is consistent in timing and magnitude with ice core observations of a 40 ppm increase in atmospheric CO2 concentration during the second half of the last deglaciation. Anomalous volcanic emissions also persist later into the Holocene, and it appears that elevated volcanic activity helps maintain high levels of CO2 during interglacials. Ice volume and atmospheric CO2 concentrations vary in near lock-step with one another over the course of the late Pleistocene glacial/inter-glacial cycles. The ocean is an obvious candidate for control of glacial time scale variations in atmospheric CO2 (1), even if the exact mechanisms are uncertain, because this large carbon reservoir exchanges with the atmosphere over millenial and shorter time scales. Here we argue that the vast carbon reservoir associated with the solid Earth also