TICMY: The Interglacial CO2 mystery (2024-2027)

Presentation

CO₂ plays a crucial role in the climate. However, changes in CO₂ concentration during the warm interglacial periods of the last 800,000 years remain unexplained. In particular, the CO₂ concentration during the “old” interglacials before the Mid Brunhes Event (MBE, about 430,000 years ago), is lower by about 25 ppm compared to the more recent interglacials. During the ancient interglacials sea level was probably lower and the ice sheets more extensive. These changes likely resulted in reduced coral reef development and expanded permafrost. Furthermore, this would have altered the exchange with marine sediments, modifying the balance carbonate ions, and ultimately the concentration of atmospheric CO₂. In this project, we are going to quantify the impact of these three key components of the carbon cycle using the coupled climate-carbon model iLOVECLIM.