Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Nature. 2001 May 17;411(6835):287-90.

A 300-million-year record of atmospheric carbon dioxide from fossil plant cuticles.

Author information

  • Department of Geological Sciences, University of Oregon, Eugene 97403-1272, USA. gregr@darkwing.uoregon.edu

Abstract

To understand better the link between atmospheric CO2 concentrations and climate over geological time, records of past CO2 are reconstructed from geochemical proxies. Although these records have provided us with a broad picture of CO2 variation throughout the Phanerozoic eon (the past 544 Myr), inconsistencies and gaps remain that still need to be resolved. Here I present a continuous 300-Myr record of stomatal abundance from fossil leaves of four genera of plants that are closely related to the present-day Ginkgo tree. Using the known relationship between leaf stomatal abundance and growing season CO2 concentrations, I reconstruct past atmospheric CO2 concentrations. For the past 300 Myr, only two intervals of low CO2 (<1,000 p.p.m.v.) are inferred, both of which coincide with known ice ages in Neogene (1-8 Myr) and early Permian (275-290 Myr) times. But for most of the Mesozoic era (65-250 Myr), CO2 levels were high (1,000-2,000 p.p.m.v.), with transient excursions to even higher CO2 (>2,000 p.p.m.v.) concentrations. These results are consistent with some reconstructions of past CO2 (refs 1, 2) and palaeotemperature records, but suggest that CO2 reconstructions based on carbon isotope proxies may be compromised by episodic outbursts of isotopically light methane. These results support the role of water vapour, methane and CO2 in greenhouse climate warming over the past 300 Myr.

Comment in

PMID:
11357126
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Nature Publishing Group
    Loading ...
    Write to the Help Desk