Open AccessCO2 and temperature decoupling at the million-year scale during the Cretaceous Greenhouse
Author(s) -
Abel Barral,
Bernard Gómez,
François Fourel,
Véronique DavieroGomez,
Christophe Lécuyer
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-08234-0
Subject(s) - greenhouse gas , climate change , cretaceous , decoupling (probability) , environmental science , global warming , greenhouse effect , global temperature , paleoclimatology , earth system science , climatology , atmospheric sciences , ecology , geology , paleontology , biology , control engineering , engineering
CO 2 is considered the main greenhouse gas involved in the current global warming and the primary driver of temperature throughout Earth’s history. However, the soundness of this relationship across time scales and during different climate states of the Earth remains uncertain. Here we explore how CO 2 and temperature are related in the framework of a Greenhouse climate state of the Earth. We reconstruct the long-term evolution of atmospheric CO 2 concentration ( p CO 2 ) throughout the Cretaceous from the carbon isotope compositions of the fossil conifer Frenelopsis . We show that p CO 2 was in the range of ca. 150–650 ppm during the Barremian–Santonian interval, far less than what is usually considered for the mid Cretaceous. Comparison with available temperature records suggest that although CO 2 may have been a main driver of temperature and primary production at kyr or smaller scales, it was a long-term consequence of the climate-biological system, being decoupled or even showing inverse trends with temperature, at Myr scales. Our analysis indicates that the relationship between CO 2 and temperature is time scale-dependent at least during Greenhouse climate states of the Earth and that primary productivity is a key factor to consider in both past and future analyses of the climate system.