Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records

✍ Scribed by J. C. Mcelwain; F. E. Mayle; D. J. Beerling

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 164 KB
• Volume: 17
• Category: Article
• ISSN: 0267-8179
• DOI: 10.1002/jqs.664

✦ Synopsis

A recent high-resolution record of Late-glacial CO 2 change from Dome Concordia in Antarctica reveals a trend of increasing CO 2 across the Younger Dryas stadial (GS-1). These results are in good agreement with previous Antarctic ice-core records. However, they contrast markedly with a proxy CO 2 record based on the stomatal approach to CO 2 reconstruction, which records a ca. 70 ppm mean CO 2 decline at the onset of GS-1. To address these apparent discrepancies we tested the validity of the stomatal-based CO 2 reconstructions from Kråkenes by obtaining further proxy CO 2 records based on a similar approach using fossil leaves from two independent lakes in Atlantic Canada. Our Late-glacial CO 2 reconstructions reveal an abrupt ca. 77 ppm decrease in atmospheric CO 2 at the onset of the Younger Dryas stadial, which lagged climatic cooling by ca. 130 yr. Furthermore, the trends recorded in the most accurate high-resolution ice-core record of CO 2 , from Dome Concordia, can be reproduced from our stomatal-based CO 2 records, when time-averaged by the mean age distribution of air contained within Dome Concordia ice (200 to 550 yr). If correct, our results indicate an abrupt drawdown of atmospheric CO 2 within two centuries at the onset of GS-1, suggesting that some re-evaluation of the behaviour of atmospheric CO 2 sinks and sources during times of rapid climatic change, such as the Late-glacial, may be required.