by Pascal Yiou
The fortnight of the Olympic Games in Paris in 2024 will take place from 26 July to 11 August, which is when the temperature in France is at its hottest. The hottest two weeks in Paris have always been August 2003, 20 years ago, with disastrous health and environmental consequences.
A team from the Laboratoire des Sciences du Climat et de l’Environnement and the Laboratoire de Météorologie Dynamique looked at what would be the worst possible heatwave between July and August by 2050. The researchers used the CMIP6 set of numerical climate simulations (used in the latest IPCC report).
These data provide a realistic basis for the possibility of reaching periods of extreme temperatures. The study’s innovation lies in the use of rare-event algorithms, derived from statistical physics, to “push” the climate models towards the most physically acceptable extreme. The results show that the 2003 record could be beaten by several degrees C well before 2050. The warm spells simulated correspond to the addition of a cyclonic ‘cold drop’ to an anticyclonic situation similar to that of 2003. This ‘cold drop’ is likely to transport very hot air from the Sahara to France, bringing additional heat to that experienced in 2003. This study is not a forecast for 2024, but a warning about the possibility of extended hot spells in the Paris region in the very near future.
Article : Yiou et al.
Journal: npj Climate and Atmospheric Science
DOI : 10.1038/s41612-023-00500-5. https://www.nature.com/articles/s41612-023-00500-5
Title : Ensembles of climate simulations to anticipate worst case heatwaves during the Paris 2024 Olympics
