title: Century-scale shifts in early holocene atmospheric CO2 concentration
abstract: The inverse relation between atmospheric carbon dioxide concentration and stomatal frequency in tree leaves provides an accurate method for detecting and quantifying century-scale carbon dioxide fluctuations. Stomatal frequency signatures of fossil birch leaves reflect an abrupt carbon dioxide increase at the beginning of the Holocene. A succeeding carbon dioxide decline matches the Preboreal Oscillation, a 150-year cooling pulse that occurred about 300 years after the onset of the Holocene. In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv.
authors.affiliation: Laboratory of Palaeobotany and Palynology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, Netherlands. Netherlands Centre for Geo-ecological Research, Faculty of Earth Sciences, Free University, De Boelelaan 1085, 1081 HV Amsterdam, Netherla.
authors.initials: F
authors.lastname: Wagner
authors.initials: SJ
authors.lastname: Bohncke
authors.initials: DL
authors.lastname: Dilcher
authors.initials: WM
authors.lastname: Kurschner
authors.lastname: van Geel B
authors.initials: H
authors.lastname: Visscher