Emergence of human influence on summer record‐breaking temperatures over Europe

Observational analysis of Europe summer record‐breaking temperatures suggests that their occurrence differs from that expected in a stationary climate since the late 1980s. The observed cold and warm record evolution is well simulated by the ensemble mean of 27 coupled models from the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that this evolution is still today within the range of internal variability derived from CMIP5 preindustrial simulations. We then estimate a time of emergence of the summer record anthropogenic influence in a world under a business as usual greenhouse gas emission scenario. We suggest a time of emergence around 2020 for the cold records and 2030 for the warm ones with an uncertainty of ± 20 years. By 2100, the multimodel ensemble mean indicates a tenfold increase of the number of warm records compared to the first half of the twentieth century and the quasi‐disappearance of cold records. Key Points More (less) frequent summer daily warm (cold) record‐breaking temperatures in Europe by 2100 Emergence of human influence projected in the 2030s (2020s) for the warm (cold) records, ± 20 years