Erich Fischer from the Institute for Atmospheric and Climate Science, ETH Zurichis guest of Nicola Maher (MPI-M) and Jochem Marotzke (MPI-M).
Time: 3:15 PM, Room 22/23 Bundestraße 53 (ground floor).
A plethora of noise: Quantifying changes in extremes in the presence of large internal variability
Decision makers express a need for reliable information on changes in climatic extremes in the coming decades. However, projections at these time scales involve large irreducible uncertainties due to internal variability. I will demonstrate that despite large uncertainties at local scale, projections in an aggregated spatial perspective are consistent even for the coming decades. Furthermore, models agree reasonably well on the forced response of temperature and heavy precipitation extremes, the pattern of change in the absence of internal variability. Thus, I argue that it is vital to specify whether model agreement refers to the forced response or for individual realization. However, ultimately our confidence in changes of extremes does not only depend model agreement but the consistency between different lines of evidence — the combination of process understanding, agreement across a hierarchy of models and the wealth of observational evidence.