title: Paleobotanical evidence for near present-day levels of atmospheric Co2 during part of the tertiary.
abstract: Understanding the link between the greenhouse gas carbon dioxide (CO(2)) and Earth's temperature underpins much of paleoclimatology and our predictions of future global warming. Here, we use the inverse relationship between leaf stomatal indices and the partial pressure of CO(2) in modern Ginkgo biloba and Metasequoia glyptostroboides to develop a CO(2) reconstruction based on fossil Ginkgo and Metasequoia cuticles for the middle Paleocene to early Eocene and middle Miocene. Our reconstruction indicates that CO(2) remained between 300 and 450 parts per million by volume for these intervals with the exception of a single high estimate near the Paleocene/Eocene boundary. These results suggest that factors in addition to CO(2) are required to explain these past intervals of global warmth.
authors: Department of Geology and Geophysics, Yale University, Post Office Box 208109, New Haven, CT 06520-8109, USA. dana.royer@yale.edu
authors: D L
authors: DL
authors: Royer
authors: S L
authors: SL
authors: Wing
authors: D J
authors: DJ
authors: Beerling
authors: D W
authors: DW
authors: Jolley
authors: P L
authors: PL
authors: Koch
authors: L J
authors: LJ
authors: Hickey
authors: R A
authors: RA
authors: Berner
mesh_terms: D001272:Atmosphere; D002245:Carbon Dioxide; D002980:Climate; D032462:Cycadopsida / Q000166:cytology*; D005580:Fossils; D020441:Ginkgo biloba; D010313:Partial Pressure; D018515:Plant Leaves / Q000166:cytology; D010946:Plants, Medicinal; D013696:Temperature; D013995:Time
chemical_list: D002245:Carbon Dioxide