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PhD Defense : Aurélien LINÉ : ” Modulation of European near-term climate change by multi-decadal internal variability “

  Thursday 21 December 2023 at 15h00

  CERFACS - Toulouse - France       Organized by Nathalie BROUSSET    

Résumé :

  • Observed climate change results from the superposition of the response of the climate system to changes in external forcings, mainly associated with anthropogenic greenhouse gas emissions, and the effects of spontaneous climate fluctuations, or internal variability.
    This thesis describes, quantifies and analyses the modulation by internal variability of climate change attributable to human activities for the winter season, in Europe and in the near term (the next two decades), using a set of climate simulations of the recent historical period and future scenarios produced by several models. The climate projections show that, in the near term, the uncertainty associated with the anthropogenic emissions scenarios is negligible and is dominated by the uncertainty associated with internal variability, which is itself greater than the uncertainty associated with the models, at these timescales for Europe. By analysing a very large number of projections (nearly 700), this thesis uses a ‘storyline’ approach to identify plausible trajectories of climate change linked to specific and discriminating modes of internal variability for Europe, trajectories in which anthropogenic climate change is either strongly amplified or strongly attenuated, or even of opposite sign for certain combinations of modes. We show that taking into account the diversity of trajectories and the associated physical processes is essential for implementing climate change adaptation measures and risk management, particularly those linked to changes in the intensity and frequency of extreme events, which we study in detail. This thesis opens up new prospects in terms of predicting the rate of warming in Europe.

Jury :

  • Susanna CORTI, Isac, CNR, Referee
  • Francisco DOBLAS REYES,BSC, Referee
  • Didier SWINGEDOUW, Université de Bordeaux, Referee
  • Juliette MIGNOT, IRD, Examiner
  • Aurélien RIBES, Météo-France, Examiner
  • Sylvie PAREY, EDF, Examiner
  • Christophe CASSOU, CNRS-CECI UMR 5318 Director
  • Rym MSADEK, CNRS-CECI UMR 5318, Co-director