Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records

Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon di...

Full description

Saved in:
Bibliographic Details
Published in:Nature (London) 2015-02, Vol.518 (7537), p.49-54
Main Authors: Martínez-Botí, M A, Foster, G L, Chalk, T B, Rohling, E J, Sexton, P F, Lunt, D J, Pancost, R D, Badger, M P S, Schmidt, D N
Format: Article
Language:English
Subjects:
Atmosphere - chemistry
Boron - analysis
Boron - chemistry
Carbon Dioxide - analysis
Climate
Climate change
Environmental Sciences
Equilibrium
Estimates
Feedback
Foraminifera - metabolism
Geologic Sediments - chemistry
Geology
Global Changes
Global warming
History, Ancient
Hydrogen-Ion Concentration
Ice Cover
Oceans and Seas
Oxygen Isotopes
Temperature
Time Factors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.
ISSN:0028-0836
1476-4687
DOI:10.1038/nature14145