Preserving History Amid Climate Change: Heritage Site Conservation
The ever-pervasive nature of climate change has impacted all facets of society and spurred scientific research into alternative energy sources, developing carbon-negative materials, and designing sustainable infrastructure, amongst many other research topics. These research directions seek to develop new technologies to tackle climate change consequences before they happen. However, along with looking towards the future, it is just as important to understand how we can preserve the past as climate change impacts historical items, materials, and architecture. Focusing on the impact of climate change on historical sites, cultural conservation research has evolved to include understanding how climate change impacts cultural heritage sites, and how we can continue to preserve these sites.
Cultural outdoor heritage is prone to damage from climate change, given the direct exposure to atmospheric conditions and general vulnerability to climatic changes. However, the impact of climate change on outdoor built cultural heritage is poorly studied (Esteban-Cantillo et al., 2024). As of 2023, the United Nations Educational, Scientific and Cultural Organization (UNESCO) indicates 34 cultural properties impacted by climate change, of the 1,199 cultural and natural properties currently inscribed on the World Heritage list. However, of the studies on cultural heritage and climate change, the research is skewed towards European sites and away from Global South and low-income countries, and so the number of sites impacted by climate change is higher (Esteban-Cantillo et al., 2024; Nguyen & Baker, 2023). One example of damage incurred includes the Archaeological Ruins of Mohenjo Daro and the Historical Monuments at Makli in Pakistan, which torrential rains impacted in September 2022. Outer walls at Mohenjo Daro were damaged or collapsed, and other larger walls separated from rooms and chambers (Nguyen & Baker, 2023). This is just one instance of the damage caused by climate change. Models and simulations of damage to heritage sites provide insight into possible damage and potential preventative measures.
Several models incorporate environmental variables such as temperature, humidity, and wind speed to estimate the damage to sites, using observational data from weather stations and other readily available sources (Esteban-Cantillo et al., 2024; Kotova et al., 2023). Current measures for damage measure impact upon materials in the sites, such as limestone, marble, and other stones (Esteban-Cantillo et al., 2024). Among the variables assessed and the different approaches, water, and precipitation are the primary factors impacting the future deterioration of cultural heritage sites (Esteban-Cantillo et al., 2024). Regarding observed damages, the materials can recess or erode, and stressors can also be introduced into the materials via precipitation and air pollution (Esteban-Cantillo et al., 2024). Sites in urban and coastal areas are, therefore, particularly susceptible to damage due to the higher exposure to environmental contaminants and precipitation (Bonazza & Sardella, 2023).
Although models provide an idea of the future environmental hazards to prepare for, Kotova et al (2023). highlight the limitations of climate models. Using the Germany KERES platform, models using “basic” climate variables and observable datasets for temperature, precipitation, and wind speed were considered. However, no single model emerged as the best, as all had uncertainties arising from the observations. Another key variable that cannot be effectively modeled currently is convection, which drives heat and moisture in the atmosphere but cannot be represented by grid-scale processes that can be replicated in a model. Improving climate models to include these variables and removing biases is crucial to a comprehensive climate model for preventative conservation measures.
With a consensus that heritage sites are facing accelerated deterioration due to climate change, research directions are pointing towards improving site infrastructure to prevent disasters according to the sites. Planning for disaster risk in heritage sites can also be applied to future building planning and ensuring sites last beyond. While protecting against gradual climate change and air pollution is essential for preserving cultural heritage sites, extreme weather events can significantly damage historical sites (Bonazza & Sardella, 2023; Esteban-Cantillo et al., 2024; Kotova et al., 2023; Nguyen & Baker, 2023). Kapsomenakis et al. reported wildfires, extreme heat, extreme precipitation, landslides, flooding, aridity, frost, and sea level rise to be the six major extreme disasters resulting from climate change (Kapsomenakis et al., 2023). Although multiple research articles focus on preparing for climate change hazards, the barriers to such preparation are multifold. The most significant barriers include collaboration and cooperation between stakeholders and institutions, as well as regulatory and policy challenges (Nguyen & Baker, 2023). Methods towards preparation also vary, including relying on local community methods, tackling climate change consequences, and using past environmental hazard protection measures as a model for future preventative actions. Cooperation between humanists and scientists is crucial, as is between Global North and Global South, given the disparity in research reported between the two regions. Cultural heritage sites provide crucial insight into human history and continue to play significant roles in local communities. Preserving these sites is necessary to ensure that cultural practices are not lost and that the use of construction materials in these sites remains viable.
Works Cited
*Cover image by Saqib Qayyum - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31519717
Bonazza, A., & Sardella, A. (2023). Climate Change and Cultural Heritage: Methods and Approaches for Damage and Risk Assessment Addressed to a Practical Application. Heritage, 6(4), Article 4. https://doi.org/10.3390/heritage6040190
Esteban-Cantillo, O. J., Menendez, B., & Quesada, B. (2024). Climate change and air pollution impacts on cultural heritage building materials in Europe and Mexico. Science of The Total Environment, 921, 170945. https://doi.org/10.1016/j.scitotenv.2024.170945
Kapsomenakis, J., Douvis, C., Poupkou, A., Zerefos, S., Solomos, S., Stavraka, T., Melis, N. S., Kyriakidis, E., Kremlis, G., & Zerefos, C. (2023). Climate change threats to cultural and natural heritage UNESCO sites in the Mediterranean. Environment, Development and Sustainability, 25(12), 14519–14544. https://doi.org/10.1007/s10668-022-02677-w
Kotova, L., Leissner, J., Winkler, M., Kilian, R., Bichlmair, S., Antretter, F., Moßgraber, J., Reuter, J., Hellmund, T., Matheja, K., Rohde, M., & Mikolajewicz, U. (2023). Making use of climate information for sustainable preservation of cultural heritage: Applications to the KERES project. Heritage Science, 11(1), 18. https://doi.org/10.1186/s40494-022-00853-9
Nguyen, K. N., & Baker, S. (2023). Climate Change and UNESCO World Heritage-Listed Cultural Properties: A Systematic Review, 2008–2021. Heritage, 6(3), Article 3. https://doi.org/10.3390/heritage6030126
