Predicting long term freeze–thaw risks on Europe built heritage and archaeological sites in a changing climate Carlota M. Grossi a, ⁎ , Peter Brimblecombe a , Ian Harris b a School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK b Climate Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK Received 10 August 2006; received in revised form 15 November 2006; accepted 15 February 2007 Available online 2 April 2007 Abstract This work aims to predict the evolution in freezing processes due to climate change during the 21st century and the potential damage to historic structures and archaeological remains in Europe. We have developed a range of techniques to convert climate data into parameters related to the freeze–thaw processes and study their progression within the A2 scenario using the Hadley HadCM3 Model , from 1961 to 2099. Freezing and thawing is important because it represents a process where a phase change occurs at an exact temperature. A few degrees change in temperature or small percentages change in precipitation amount do not initially seem to present a threat to materials. However, freeze–thaw events occur at fixed temperature, so the effects of small temperature changes can be amplified. Our results suggest that much of temperate Europe will see a significantly reduced incidence of freezing in the future. This should mean that porous stone typically used in the monuments of temperate areas may be less vulnerable to frost damage in the future. Warmer temperatures in the far north look set to affect archaeological sites that have been preserved in the permafrost. These changes may also affect the foundations of structures and induce landslides. Exploring the range of possible changes allows us to contemplate appropriate contingencies and support strategic decision making by heritage managers. © 2007 Elsevier B.V. All rights reserved. Keywords: Freeze–thaw; Climate change; Hadley Model HadCM3 Scenario A2; Cultural heritage; Porous stone; Archaeological remains 1. Introduction 1.1. Frost and cultural heritage Most cultural heritage structures are subjected to a range of environmental risks such as salt damage, biological attack and air pollution. Frost damage is a further important physical cause of decay of building stones (Honeycombe, 1990). It is usually the result of an increase in water volume when freezing within pores or fissures. This can cause internal tensions and hydraulic pressure within the stone. The intensity, rate and duration of freezing, the cyclic action, as well as interstitial moisture determine the severity of the effect (Hall, 2004). The characteristics of pores (Everett, 1961), fissures and weakness planes of rocks also condition the sensitivity to frost. Soluble salts within the voids can greatly increase (Jerwood et al., 1990a,b; Matsuoka et al., 1996; Williams and Robinson, 2001) and occasion- ally decrease the damage due to freezing water (McGreevy, 1982). Noticeable frost damage effects mainly take place on porous materials (i.e. porosity >5%) saturated in water. Shaffer in his pioneering (1932) Science of the Total Environment 377 (2007) 273 – 281 www.elsevier.com/locate/scitotenv ⁎ Corresponding author. E-mail address: c.grossi-sampedro@uea.ac.uk (C.M. Grossi). 0048-9697/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2007.02.014