Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal

Loading...
Thumbnail Image
Date
2019
Volume
5
Issue
4
Journal Title
Title
Series Titel
Publisher
Washington, DC [u.a.] : Assoc.
Link to publishers version
Abstract

Variations in Earth's orbit pace the glacial-interglacial cycles of the Quaternary, but the mechanisms that transform regional and seasonal variations in solar insolation into glacial-interglacial cycles are still elusive. Here, we present transient simulations of coevolution of climate, ice sheets, and carbon cycle over the past 3 million years. We show that a gradual lowering of atmospheric CO2 and regolith removal are essential to reproduce the evolution of climate variability over the Quaternary. The long-term CO2 decrease leads to the initiation of Northern Hemisphere glaciation and an increase in the amplitude of glacial-interglacial variations, while the combined effect of CO2 decline and regolith removal controls the timing of the transition from a 41,000- to 100,000-year world. Our results suggest that the current CO2 concentration is unprecedented over the past 3 million years and that global temperature never exceeded the preindustrial value by more than 2°C during the Quaternary.

Description
Keywords
Carbon dioxide, Orbits, Salinity measurement, Climate variability, CO2 concentration, Glacial-interglacial cycles, Global temperatures, Northern hemisphere glaciations, Seasonal variation, Solar insolation, Transient simulation, Glacial geology
Citation
Willeit, M., Ganopolski, A., Calov, R., & Brovkin, V. (2019). Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal. 5(4). https://doi.org//10.1126/sciadv.aav7337
License
CC BY 4.0 Unported