Responsable : Franck Bassinot, LSCE

Objectifs et stratégie

Past climate archives have documented abrupt or non-linear changes, occurring sometimes in less than a few decades. These abrupt climate changes occur when the climate system is forced to cross some threshold, triggering a transition to a new state at a rate determined by the climate system itself and faster than the cause. Chaotic processes in the climate system may allow the cause of such an abrupt climate change to be undetectably small.

In order to properly address the risk of future abrupt climatic changes, the WP5 will conduct concerted efforts for the analysis and interpretation of high-resolution past climate archives, both on the continents (i.e. speleothems, lacustrine sediments, ice cores) and in the ocean (shallow and deep-sea corals, marine sediments), and will compare these data with models outputs (especially, proxy forward models) in order to better understand the causes, mechanisms and impacts of abrupt climatic changes, and take full advantage of paleo-archives to unravel potential climate crisis ahead.

Key efforts will be devoted (i) to understand the importance of mean, initial climate conditions on natural climate variability and abrupt climatic shifts, (ii) to identify and quantify thresholds, and (iii) to highlight potential precursors that could help us to predict the occurrence of future tipping points. (These early warning signals likely include changes of climate variability, whose study is therefore included in WP5 long-term goals).