期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2002
卷号：99
期号：19
页码：12011-12014
DOI：10.1073/pnas.182420699
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：By applying the inverse relation between numbers of leaf stomata and atmospheric CO2 concentration, stomatal frequency analysis of fossil birch leaves from lake deposits in Denmark reveals a century-scale CO2 change during the prominent Holocene cooling event that occurred in the North Atlantic region between 8,400 and 8,100 years B.P. In contrast to conventional CO2 reconstructions based on ice cores from Antarctica, quantification of the stomatal frequency signal corroborates a distinctive temperature-CO2 correlation. Results indicate a global CO2 decline of {approx}25 ppm by volume over {approx}300 years. This reduction is in harmony with observed and modeled lowering of North Atlantic sea-surface temperatures associated with a short-term weakening of thermohaline circulation.
