The session will concentrate on a better understanding of the precise timing, magnitude, and boundary conditions of the most natural extreme events in the past such as severe flood, temperature anomalies, storms, and drought events. Only with a reliable and comprehensive understanding of the past extremes variability, projections about the future occurrence of these natural hazard can be made. This is especially crucial in light of the current global warming, expected to lead to an intensification of the hydrological cycle and shifting frequency and magnitude of hydrometeorological extremes.

We invite contributions, to present information based on the analysis of historical data, findings from instrumental data, lake and marine sediments, tree rings, speleothems, molluscs or similar archives, which can be explored to identify the variability of natural extremes on decadal to millennial time-scales and, to provide an overview of the physical processes controlling extreme occurrence and magnitude throughout various global climate states. We invite further contributions that result from numerical model output that add to the understanding of the underlying processes driving these events. Contributions that deal with both proxy data and climate modelling are particularly welcomed.

Furthermore we welcome results from statistical and modelling efforts that lead to the understanding of the synoptics and forcing of weather events, i.e. whether climate extremes are a stochastic component of internal variations or are associated with specific boundary conditions and external forcing factors such as volcanic and solar activity and/or, for instance, sea surface temperature changes or patterns of teleconnections (e.g. AMO, NAO and ENSO).

This knowledge is nowadays needed to better assess the potential impact of contemporary climatic change on extreme event occurrences and to appropriately establish hazard mitigation plans and prevent high socio-economic damages.