Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal
Willeit, M.; Ganopolski, A.; Calov, R.; Brovkin, V. (2019). Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal. Science Advances 5(4): eaav7337. https://dx.doi.org/10.1126/sciadv.aav7337
In: Science Advances. AAAS: New York. ISSN 2375-2548; e-ISSN 2375-2548, meer
|   |
| Auteurs | | Top |
- Willeit, M.
- Ganopolski, A.
- Calov, R.
- Brovkin, V.
|
|
|
| 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. |
|
