The urgent challenge of anthropogenic climate change has motivated the study of paleoclimatology - the history of the Earth system. Over the last few decades, an increasing amount of data has been recovered, from ice cores, tree rings, lake and ocean sediments, for example. For historians and archaeologists, paleoclimatology offers a treasure trove of new knowledge, a suite " of natural archives " to complement and enrich our traditional documentary archives.
The conclusion that has emerged is that the environment plays a major role in the destiny of human societies, yet our knowledge of paleoclimate has generated more questions than answers. Why ? Climate is a complex dynamic system, characterized by non-linearity, feedback loops and tipping points. Human societies are also complex systems, always situated between fragility and resilience - sometimes resistant to disturbance, sometimes sensitive to rapid change with cascading effects. It is precisely because of this complexity that the long-term study of the history of societies and the environment is of major importance for citizens and political decision-makers in facing the future risks of an unbalanced world.