Conservation-restoration costs for limestone façades due to air pollution in Krakow, Poland, meeting European target values and expected climate change

Conservation-restoration costs due to air pollution weathering of limestone façades in the city of Krakow, Poland, were assessed. For the air pollution situation in 2013-15, and for suggested weathering rate targets for 2020 and 2050, representing two and two point five times the rural background corrosion, the costs due to air pollution were found to be 67%, 49% and 33% of the total cost due to atmospheric chemical weathering. Savings of 27% and 51%, of the total weathering costs, could be obtained by meeting the two targets, representing simultaneous reduction of the SO2, NO2 and PM10 concentrations, by 36% and 67% from the 2013-15 level. Six percent reduction would compensate for the expected effect of climate change until the period 2081-2100. The cost increase due to this climate change was found to be three percent of the weathering costs, and four, nine and 16% of the cost due to the air pollution, at the present situation (2013-15), the 2050 and 2020 targets, respectively. Meeting the EU 2008 Air Quality Directive, would give similar savings, as meeting the 2020 target. Absolute costs estimates should be adjusted with the fraction importance of atmospheric chemical weathering for the implementation of conservation-restoration.