Future climate scenarios in indoor environment for preventive conservation of cultural heritage in unconditioned historical buildings in the Mediterranean area.

Indoor climate in historic buildings without air conditioning systems results from the interaction between the building envelope and the outdoor climate forcing. Any change in outdoor climate can affect the indoor one, playing a key role in the deterioration of cultural heritage. The long indoor/outdoor climate measurements collected in the State Archive in Palermo (Italy) were used to assess the buffering role of the building envelope to the outdoor climate. Assuming that the building envelope features negligibly change over time, it was set a heat transfer function to reconstruct future indoor climate from outdoor climate ones. To this purpose, three Shared Socio-economic Pathways (SSPs) from the 6th Assessment Report of the Intergovernmental Panel on Climate Change were considered. Thereafter, it was studied whether future indoor climate might favour deterioration mechanisms affecting vulnerable materials ($e.g.$, cellulose-based, wood). The expected persistence of warm conditions in the site according to SSP5-8.5 could favour both chemical reactions and temperature-dependent adult insects' proliferation up to three times more than current conditions.