Carbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Bauska, Thomas K., Baggenstos, Daniel, Brook, Edward J., Mix, Alan C., Marcott, Shaun A., Petrenko, Vasilii V., Schaefer, Hinrich, Severinghaus, Jeffrey P., Lee, James E.
• Format: Text
• Language: English
• Published: National Academy of Sciences 2016
• Subjects: Physical Sciences; Antarctic; Taylor Glacier; Antarc*; Antarctica
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822573/; http://www.ncbi.nlm.nih.gov/pubmed/26976561; https://doi.org/10.1073/pnas.1513868113

Antarctic ice cores provide a precise, well-dated history of increasing atmospheric CO2 during the last glacial to interglacial transition. However, the mechanisms that drive the increase remain unclear. Here we reconstruct a key indicator of the sources of atmospheric CO2 by measuring the stable isotopic composition of CO2 in samples spanning the period from 22,000 to 11,000 years ago from Taylor Glacier, Antarctica. Improvements in precision and resolution allow us to fingerprint CO2 sources on the centennial scale. The data reveal two intervals of rapid CO2 rise that are plausibly driven by sources from land carbon (at 16.3 and 12.9 ka) and two others that appear fundamentally different and likely reflect a combination of sources (at 14.6 and 11.5 ka).