Authors: Soria, Carmen; Serlupi-Crescenzi, Matteo;Pacifici, Michela;Rondinini, Carlo;

The frequency and intensity of extreme climate events such as hurricanes, floods and droughts are projected to increase over the next decades, significantly impacting global biodiversity. As endotherms, mammals can maintain a high and constant body temperature, providing a high degree of thermal independence. However, exposure to extreme droughts and warm spells will potentially limit their capacity to thermoregulate, increasing their extinction risk. Therefore, identifying which mammal populations will be exposed to these events is essential to design proactive and effective conservation measures. Here, we derived global maps of future exposure of mammal populations to extreme droughts, warm spells, and both. We considered two different periods (2021 – 2040 and 2081 – 2100) and three greenhouse gas emission scenarios (RCP2.6, RCP4.5 and RCP8.5). To account for intraspecific differences in tolerance to extremes, we defined as a population the intersection of species’ distributions and biomes. We identified as exposed the areas of the population that will experience drought and/or warm spell values substantially higher than those experienced during the historical period (1961 – 1990). We found that exposure to extreme droughts, warm spells, and both will increase with period and emission scenario.