Bioclimatic characterisation of the Mediterranean region: future climate projections for Spain, Italy and Tunisia

The present study provides a meteorological and bioclimatic characterisation of three Mediterranean areas: Spain, Italy and Tunisia. This includes, on the one hand, an evaluation of the past climate using meteorological data collected from 1931 to 1994. On the other hand, the future climate characterisation has been constructed for each study area, under the projected A1B emission scenario for the 2081 to 2100 period. Three Bioclimatic Indices are used to compare the annual and seasonal climate from these past periods through to these future periods: the Ombrothermic Index, the Continentality Index and the Thermicity Index. A clear tendency toward semicontinentality in the Mediterranean basin is observed, and higher thermicity is expected in the future. The Ombroclimatic Index, and especially the seasonal indices, is the most helpful of these Bioclimatic Indices, showing that the southern Mediterranean areas would be the most vulnerable to climate change.