RÉSUMÉ
Source : ANR - Agence Nationale de la Recherche
Ce projet de recherche fondamentale vise à déterminer les conditions météorologiques, environnementales et sanitaires qui ont prévalu aux 18ème et 19ème siècle, à partir d'archives historiques et de simulations régionales du climat. Nous nous focaliserons sur la période de 1750 à 1850, qui inclut deux éruptions volcaniques (Laki, 1783 ; Tambora, 1815) et quelques événements climatiques extrêmes. En parallèle, nous utiliserons des simulations numériques du climat des 1000 dernières années pour contraindre un modèle régional centré sur la région péri-méditerranéenne afin de simuler le climat à fine échelle pour des événements marquants (vagues de chaleur, sécheresses) et les éruptions volcaniques. Une comparaison détaillée entre ces simulations régionales et les observations des extrêmes climatiques sera aussi effectuée.
Source : LSCE - Laboratoire des Sciences du Climat et de l'Environnement
This fundamental research project aims at determining meteorological, environmental and sanitary conditions that prevailed during the 18th and 19th centuries, from historical archives and regional model simulations. Examples of climate influences on public health are numerous. Those influences can be either direct (the climatic or environmental event creates a sanitary risk like thermal stress), or indirect (the event creates conditions that jeopardize crops, deteriorate water availability, etc.). Their consequences are increases in morbidity or excess mortality due to infectious diseases, intoxications, food shortages and social unrest. Even tough modern agriculture is less sensitive to climatic hazard, episodes like the European heatwave in 2003 have shown that society is sensitive to climate extreme events.
A goal of this research project is to identify the causes of sanitary accidents in the past centuries, and examine the role of climate and environmental fluctuations on those accidents. Recent epidemiologic studies have allowed determining thresholds of atmospheric pollutant concentrations on sanitary risk (cancers, heart and lung diseases) on specific cases and populations (Pope et al. 2002, Pope et al. 2004, Jerrett et al. 2007). This type of study was also carried out after the 2003 heatwave in France (Vandentorren et al. 2004). Yet, the documentation of causes of increased death rate and the investigation of their connection with climate variability and environmental change have never been undertaken in a quantitative way, and over time scales that are sufficiently long to obtain an idea on causal links during history. We propose to set a historical context for this type of events in order to qualify and quantify the response of society to natural climate and environmental fluctuations.
We shall focus on the period covering 1750 to 1850, which includes two volcanic eruptions (Laki in 1783 and Tambora in 1815), and several extreme climate events. The challenge of this project is that very few meteorological data are available to date. In parallel, we will use climate numerical simulations of the last 1000 years (from IPSL and CNRM) to constrain a regional climate model centered over the Western Europe and Mediterranean regions, in order to simulate fine scale meteorology and atmospheric composition for those events (heatwaves, droughts) and volcanic eruption. In particular, we will use the CHIMERE/WRF model and LMDzT/INCA to evaluate how the gaseous species and aerosols emissions of the Laki eruption were transported to France, and could cause potential health problems. A detailed comparison between those regional simulations and observations will be performed.