Abstract

Extreme events are an expression of natural climate variability. Since anthropogenic emissions affect global climate, it is natural to wonder whether recent observed extreme events are a manifestation of anthropogenic climate change. This thesis aims at contributing to the understanding of the influence of anthopogenic climate change on observed extreme events, while assessing whether and how this scientific information - and more generally, the science of extreme event attribution - could be useful for society. I propose statistical tools to achieve the former, while relying on qualitative interviews for the latter.The statistical part focuses on European heatwaves. I quantify the role played by the atmospheric circulation in the intensity of four recent heatwaves. This analysis is based on flow analogues, which identify days with a similar circulation pattern than the event of interest. I then disentangle the influence of climate change on the dynamical and non-dynamical processes leading to heatwaves. I calculate trends in the occurrence of circulation patterns leading to high temperatures and trends in temperature for a fixed circulation pattern, applied to the 2003 Western Europe and 2010 Russia heatwaves. I find that the significance of the results depend on the event of interest, highlighting the value of calculating trends for very specific types of circulation.The epistemological part evaluates the potential social uses of extreme event attribution. I assess how it could inform international climate negotiations, more specifically loss and damage, in response to a number of claims from scientists going in this direction. I find that the only potential role EEA could play to boost the loss and damage agenda would be to raise awareness for policy makers, aside from the negotiation process itself. I also evaluate how the different motivations stated by EEA scientists in interviews fare compared to the existing evidence on social use of this type of scientific information. I show that the social relevance of EEA results is ambiguous, and that there is a lack of empirical data to better understand how different non-scientific stakeholders react and appropriate EEA information.