Prolonged cold periods in the Holocene due to high-frequency climate forcing
Evelien JC van Dijk 1, Johann Jungclaus2, Michael Sigl3, Claudia Timmreck2, Kirstin Krüger1
Affiliations: 1Department of Geosciences, University of Oslo, Oslo, Norway; 2Max Planck Institute for Meteorology, Hamburg, Germany; 3Department of Physics and the Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
Presentation type: Talk [Invited]
Presentation time: Monday 08:45 - 09:00, Room R290
Programme No: 6.1.2
Abstract
Understanding climate variability across interannual to centennial timescales is critical, as it encompasses the natural range of climate fluctuations that early human agricultural societies had to adapt to. Deviations from the long-term mean climate are often associated with both societal collapse and periods of prosperity and expansion. Here, we show that contrary to what global paleo-proxy reconstructions suggest, the mid to late-Holocene was not a period of climate stability. Long-lasting cold periods in the Holocene have only recently been detected in local proxies, and not a lot is known about these periods. We use mid- to late-Holocene Earth System Model simulations, forced by state-of-the-art reconstructions of volcanic forcing to show that in the model simulation, eleven long-lasting cold periods occurred in the Northern Hemisphere during the past 8000 years. These periods correlate with enhanced volcanic activity, where the clustering of volcanic eruptions induced a prolonged cooling effect through gradual ocean-sea ice feedback. These findings challenge the prevailing notion of the Holocene as a period characterized by climate stability, as portrayed in multi-proxy climate reconstructions. Instead, our simulations provide an improved representation of amplitude and timing of temperature variations on sub-centennial timescales.