Integrating past variability in climate-driven Mediterranean fire hazard assessments for 2020-2100

International audienceIn the Mediterranean basin, Corsica (French island) harbours among the best-preserved Mediterranean forest ecosystems and its high biodiversity could be threatened by the climate and disturbance-regime changes due to the global warming. This study aims i) to estimate the future climate-related re hazard in Corsica for the current century (2020-2100) based on two RCP scenarios (RCP4.5 and RCP8.5), and ii) to compare the predicted trends with the entire Holocene period for which re hazard has previously been assessed. An ensemble of future climate simulations from two IPCC RCP scenarios has been used to compute the Monthly Drought Code (MDC) and the Fire Season Length (FSL) and to assess the level of re hazard assessment. Here, we show that the MDC and the FSL would both strongly increase over the next decades due to the combined effect of temperature increase and precipitation decrease in the Corsica region. Moreover, the maximum Holocene FLS (7000 to 9000 years ago), will be reached (and even exceeded depending upon the scenario) after 2040. For the rst time in the Holocene, we may be confronted to an increase in the number of re-prone months driven by climate combined with many human-caused ignitions. This combination should increase the burned area from 15-140%. For the next 30 years, the game seems to be already played as both RCP scenarios resulted in similar increase in re hazard intensity and duration. It is thus mandatory to reconsider re-management and re-prevention policy to mitigate the future re risk, and its catastrophic consequences for ecosystems, population, and economy