1. Introduction
Our tangible cultural heritage is threatened by gradually shifting weather patterns and extreme events. An increase in temperature together with changes in precipitation, relative humidity, and wind, for instance, can negatively impact on the materials comprising cultural heritage assets. This is because a change in average climatic conditions as well as changes in the frequency and intensity of severe weather events can affect the biological, chemical, and physical mechanisms leading to degradation of the assets [
1,
2,
3,
4,
5]. This includes an increase in the freeze-thaw cycle in northern Europe, extreme heat and droughts in the Mediterranean region, the overall decrease in summer precipitation in Europe, and an increase in winter storms and heavy precipitation events in the Atlantic region. In addition, cultural heritage sites in coastal regions are particularly at risk of sea-level rising (SLR) and the occurrence of storm surges while natural hazards such as floods, landslides, earthquakes, volcanoes, and fire can also have devastating impacts on cultural heritage assets. As the outputs from global climate models project that climatic changes will grow larger over the current century with the magnitude of the projected change dependent on the selected path of greenhouse gas (GHG) emissions and the model selected, strategies need to be developed to reduce the negative consequences of climate change on sites of historical value in addition to mitigate climate change by curtailing GHG emissions.
The United Nations Framework Convention on Climate Change (UNFCCC) established the need to address both mitigation and adaptation to climate change [
6]. Hence, there are two strands to the climate change challenge. Mitigation encompasses measures and activities aimed at reducing GHG emissions or enhancing the sinks of such gases, whilst adaptation refers to any adjustments in a system in response to the actual or projected climatic stimuli [
7,
8], including changes in socio-environmental processes, perceptions, practices, and actions to reduce potential damages or to take advantage of new opportunities that may arise [
9]. Mitigation has traditionally been given more attention in climate change research and policy than adaptation [
10,
11,
12,
13]. Nonetheless, there has been increasing interest in adaptation research since the late 1990s due to the recognition that the climate is already changing and that adaptation to the already unavoidable impacts is crucial [
13,
14]. In the field of cultural heritage, mitigation can involve improving the energy efficiency of historical buildings, for instance, while building a sea wall to protect coastal heritage sites from storm surges and SLR is an example of adaptation to climate change risks.
This paper focuses on adapting cultural heritage to climate change risks and is limited to the immovable and tangible cultural heritage, for example, historical buildings, monuments, and archaeological sites. The objectives of this paper are as follows:
To understand how climate change adaptation is considered by experts in cultural heritage preservation in Europe. This includes determining the perspectives of these experts specifically on the requirements for, and opportunities and barriers to, adaptation, and the determinant factors for the implementation of adaptation efforts.
To identify current examples of best practice in the management and practical site-level strategies and methodologies for adapting cultural heritage to climate change.
2. Adapting Cultural Heritage to Climate Change Risks
Previous studies have focused on assessing the impacts of climate change on cultural heritage sites in Europe [
1,
2,
3,
4,
5,
15], with limited research on adaptation. Efforts in the area of adaptation are yet limited to the dissemination of guidelines and recommendations for implementing adaptation measures [
1,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25], the identification of the determinants of adaptive capacity [
26], and the identification of the barriers to adaptation [
27,
28,
29,
30]. Sabbioni et al. [
1,
16] developed guidelines for adapting the European cultural heritage to climate change impacts, which were later adopted by the Italian Strategic Agenda [
31,
32]. These included strategies for both physical adaptation and for adjusting management practices. Examples of the latter include improving the monitoring, maintenance, and preparedness to floods and landslides at cultural heritage sites [
1,
16]. Heathcote et al. [
17] described the adaptive measures suggested in the Historic England climate change adaptation plan to cope with the impacts of climate change on cultural heritage in England, for example, developing approaches to deal with change and loss. Haugen and Mattson [
18] investigated the impacts of climate change on cultural heritage in Norway, and recommended adaptive measures to deal with the risks identified. Also in Norway, Grøntoft [
23] discussed options for adapting the surface of heritage material and the facades of heritage buildings to the impacts of climate change, including encouraging the adoption of adaptive measures that preserve building surfaces, incorporating climate change projections in building regulations, and developing new technologies to adapt buildings to future climatic conditions.
In addition to providing adaptive solutions to climate change impacts, some studies have examined the determinants of adaptive capacity in the field of cultural heritage, the role of tourism in supporting adaptation efforts, and key issues associated with adaptation of cultural heritage to climate change [
25,
26]. Phillips [
26] investigated the adaptive capacity to climate change at cultural heritage sites and identified access to information, authority, resources, cognitive factors, leadership, and learning capacity as the key determinants. Hall [
25] and Hall et al. [
24] gave insight into the role of tourism in adapting cultural heritage to climate change. Furthermore, Hall et al. [
24] identified key themes in dealing with the consequences of climate change for cultural heritage, such as the importance of using integrated approaches in adaptation and preserving the values interconnected with the local heritage through consultation with stakeholders that live and work within heritage sites, the need for a unified approach in cultural heritage preservation, and dealing with the paucity of funding for climate change adaptation.
Other studies have analysed climate change adaptation strategies for specific heritage typologies such as archaeological sites and historical districts located in coastal regions. A recurring theme emerging from these studies is the need to strengthen monitoring and maintenance and increase risk-preparedness and the dissemination of know-how when considering adaptation of cultural heritage to climate change. Cassar [
19] investigated the impacts of climate change on archaeological sites and suggested adopting solutions that are sensibly designed to the specific conditions of the site after a long-term programme of monitoring and maintenance. She also deliberated on the adaptive solution adopted for the Megalithic Temples, a World Heritage Site (WHS) located in Malta. Additionally, Cassar [
19] summarised the adaptation measures suggested by the UN Educational, Scientific and Cultural Organization (UNESCO) and by the International Council On Monuments and Sites (ICOMOS), who recommend increasing research, knowledge, education, engagement, the upgrading of management plans—including risk assessments—and monitoring procedures to increase the resilience of the sites. Pollard-Belsheim et al. [
20] investigated the effectiveness of existing adaptation strategies to preserve coastal archaeological sites with a focus on a range of adaptation solutions such as watertight barriers, wooden breakwaters, and gabion rock wall. Climate change adaptation solutions to archaeological sites were also studied by Carmichael et al. [
21] in indigenous communities in Australia. In the Republic of Tartasan in Russia, Usmanov et al. [
33] suggested adaptation measures to preserve coastal archaeological sites from coastal erosion such as building breakwaters, changes in land use and planting trees. Nicu [
34] also suggested planting trees to stabilise slopes as an adaptation measure to preserve the archaeological and paleontological sites of northeastern Romania, a region susceptible to landslides, a natural hazard whose occurrence could be affected by climate change. Fatorić and Seekamp [
22] examined an approach to support decision-making by promoting climate change adaptation through the sharing of information and better engagement amongst stakeholders in the historical districts of the coast of North Carolina in the United States (US).
Until now, less research has been conducted on the identification of the barriers to adapting our cultural heritage to climate change [
27,
28,
29,
30] and in considering geological hazards in the assessment of vulnerability to inform the adaptation process. Phillips [
27] investigated whether climate change is considered in the management plans of WHS in the United Kingdom (UK) and identified issues arising from its consideration, notably the lack of detailed information from climate change scenarios and the uncertainty associated with them, as well as the lack of resources, knowledge, and skills available. Also in the UK, it was noted that knowledge of geological and geomorphological processes can improve our understanding of the risk of natural hazards on WHS and thereby inform adaptation to climate change [
35]. However, natural processes have often been ignored in previous assessments of vulnerability and the inclusion of geological hazards such as landslides and groundwater flooding in vulnerability assessments is limited [
36]. Fatorić and Seekamp [
28] identified 16 barriers to adaptation of cultural heritage to climate change in the Southeast of the US, which they grouped into three main categories: institutional barriers (e.g., lack of political commitment), technical barriers (e.g., lack of technical expertise), and financial barriers (e.g., lack of funding). The barriers to adaptation identified by Carmichael et al. [
29] at cultural heritage sites in Australia were related to governance and compatibility with current management frameworks. Casey [
30] identified two categories of barriers to adapt cultural heritage sites in three US National Parks to climate change: institutional barriers, which result from existing structures and frameworks, and conceptual barriers, such as problems in prioritizing the cultural resources to be preserved and adapted, together with challenges in managing those resources. Casey [
30] also identified potential solutions to overcome those barriers, for example, including climate change in regulations and management plans.
The issue of adaptation to climate change began to be seriously considered only since the publication of the UNFCCC in the 1990s [
11,
37]. Climate change adaptation is thus a relatively new challenge and this is particularly the case in the field of cultural heritage. The impacts of climate change on cultural heritage were first mentioned in the chapter on Europe of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) in 2014. At the 21st session of the Conference of the Parties (COP21) of the UNFCCC in Paris, a number roundtable discussions on the topic of climate change and cultural heritage were organized [
38], and, following the adoption of the Paris Agreement, the World Heritage Committee of UNESCO, at their annual session in 2017 in Krakow, Poland, noted the pressing issue of climate change impacts on World Heritage properties and requested that the UNESCO World Heritage Centre support State Parties in managing climate change impacts and in strengthening collaboration with the UNFCCC and the IPCC [
39]. The World Heritage Committee is responsible for the World Heritage Convention and consists of representatives from 21 of the State Parties, which are elected by the General Assembly. This led to the IPCC consulting with UNESCO to identify topics to be incorporated as part of AR6 to be published in 2021. Climate change impacts were only briefly mentioned in AR5 and the impacts presented in the report were mainly the results of initiatives funded by the European Commission (EC) over the last 15 years such as the Noah’s Ark (2003–2007) and Climate for Culture (2009–2015) projects. These projects focused on the threats of climate change on cultural heritage with limited attention given to adaptation of cultural heritage to climate change.
There are only a few well-documented cases of adaptation of cultural heritage to climate change with most research focusing on the identification of the risks of climate change and the provision of guidelines and suggestions to adapt to those risks. A limited number of studies have examined the barriers to adapt cultural heritage sites to climate change, albeit the literature on this topic is not yet comprehensive [
40]. Heritage managers need to mitigate against the impacts of current changes in climate, including changes in the frequency and intensity of extreme events [
1], but also require awareness of the potential impacts of climate change. For this reason, it is recommended to include climate change within management plans and decision-making strategies [
15,
26]. A number of questions remain insufficiently addressed in the literature, notably, how do experts involved in the preservation of cultural heritage consider climate change? Is climate change currently included in the management of heritage sites and, if so, how? What are the opportunities and limitations in adapting cultural heritage to climate change? The answers to these questions are essential for the development of adaptation measures and to identify future research directions.
3. Materials and Methods
Semi-structured interviews were conducted in three European countries: the UK, Italy and Norway. The interviews centered on the following four questions: (1) is adaptation of cultural heritage to climate change possible? (2) Are you aware of any example(s) of management methodologies to mitigate the impacts of climate change on cultural heritage? (3) Are you aware of best practice examples in adapting cultural heritage to climate change? (4) What are the determinant factors for implementing adaptation of cultural heritage to climate change? A total of 45 interviews were conducted with experts involved in the preservation of cultural heritage. The interviewees were categorized into three main groups: 19 academics and researchers from universities and research centers in the UK, Italy, and Norway, including investigators having worked or currently working on EU projects focusing on the theme of climate change and cultural heritage; 12 members of governmental institutions working on the preservation of cultural heritage; and 14 people involved with the management of UNESCO WHS, such as managers, coordinators, and professionals. The interviewed experts on cultural heritage preservation have diverse backgrounds and specializations, including anthropologists, archaeologists, architects, conservation scientists, geologists, biologists, heritage site managers and coordinators, sustainability officers, and urban planners. The interviews were audio recorded and subsequently transcribed and analyzed using the NVivo software. (Version 11, QSR International (UK) Limited, Daresbury, Cheshire, UK).
Since there is limited research on adaptation of cultural heritage to climate change, the adoption of a qualitative methodology using semi-structured interviews was considered the most appropriate. Michalski and Bearman [
41] noted the advantage of semi-structured interviews when there is inadequate knowledge on a particular topic. The interviews were complemented with a critical analysis of the grey literature such as reports and documents gathered from the interviewees, websites of the institutions employing them or that they recommended, and books and journal articles. The former included existing management plans, national policies and guidelines, regional documents and brochures. A one-day workshop titled: “Vulnerability and adaptation of cultural heritage to climate change. Supporting decision-making in adapting cultural heritage sites to climate change” was also organized to gather further information on experts’ perceptions and also to allow for the exchange of information amongst participants. The workshop took place on 22 March 2018 at the New Lanark UNESCO WHS and was attended by 22 experts in cultural heritage preservation, including participants from academia, government institutions, and managers of heritage sites. The workshop included a site visit, a number of presentations, and an interactive part. The latter consisted of three facilitated roundtable discussions on issues related to the vulnerability and adaptation of different WHS to climate change. With regard to adaptation, the discussion particularly focused on the challenges of adaptation and opportunities for the implementation of adaptation strategies. The methodological approach selected for this study, which involved stakeholders’ interviewees and a participatory workshop, has previously been used in climate change adaptation research [
42,
43]. Ethical approval was sought and obtained through the University of the West of Scotland procedure.
4. Results
The first part of the investigation focused on understanding the participants’ perceptions on the possibility of adapting cultural heritage to climate change. How do they feel about it? Is adaptation of cultural heritage to a changing climate a challenge that can be dealt with? What are their doubts and perplexities on this topic? The majority of the participants agreed that adaptation of cultural heritage to climate change is possible (
Table 1). Some interviewees were not fully confident about this possibility and a few did not answer this question. No interviewees indicated that adaptation is not possible. The interviewees’ answers on the possibility of adapting cultural heritage to climate change were coded into three main categories to highlight their perceptions on the ‘opportunities’, ‘requirements’, and ‘barriers’ in adapting cultural heritage to climate change.
Table 2 summarizes those ‘opportunities’, as identified by the interviewees, which were classified according to the following themes: ‘moving from reactive to proactive adaptation’, ‘working on mitigation and adaptation together’, ‘strengthening monitoring and maintenance’, ‘making adaptive change’, ‘increase collaboration’, and ‘positivity’. The ‘requirements’ for more information and resources to make adaptation possible, as expressed by the interviewees, are included in
Table 3. The interviewees also identified a number of barriers to adaptation, which were classified into the following themes: ‘diversification’, ‘uncertainty’, ‘resignation’, ‘loss’, ‘preserving values, integrity and authenticity’, and ‘financial resources’ (
Table 4).
The second part of the investigation focused on the interviewees’ awareness of existing assessment frameworks for adaptation and best practice to preserving cultural heritage from the threats of climate change. The majority of the interviewees were not aware of strategies considering climate change adaptation in the management of cultural heritage assets and sites (
Table 5). The few strategies that were mentioned are to the work done by UNESCO, Historic Environment Scotland (HES), and the guidelines of the Italian national strategic agenda (
Table 6), as Italy and France are two countries that currently include cultural heritage in their National Adaptation Plan to climate change [
38]. HES is the public body for the investigation, care, and promotion of Scotland’s historic environment.
The interviewees were aware of examples of best practice in adapting cultural heritage to climate change risks. Their answers were divided into ‘managerial and decisional adaptation’ and ‘practical adaptation’ following on the classification previously used in the literature [
1]. The best practice examples in managerial and decisional adaptation to climate change were as follows: to increase fundraising, increase the production of knowledge and its dissemination, engage those involved with the heritage (owners, communities, tourists) in adaptation, promote and strengthen monitoring and maintenance, upgrade management plans to include climate change, strengthen regulations and guidelines, keep working on mitigating climate change to reduce future risks (
Table 7). Examples of practical adaptation to climate change identified by the interviewees included building defences, using roofs and shelters to protect unroofed sites, upgrading roofs and drainage systems, avoiding the use of incompatible repair materials and surface treatments, moving the heritage sites, monitoring the heritage assets and the climatic conditions, and the use of digital recording (
Table 8).
The interviewees were then asked to identify the determinant, or constraining, factors that they consider important for adapting cultural heritage sites to climate change. A list of these factors is provided in
Table 9 and categorised into the following groups: (1) Knowledge, education, communication, and awareness; (2) Management, regulations, governance, and drivers; (3) Economic factors; (4) Cultural values; (5) Health and safety concerns; (6) Time.
6. Conclusions
Adaptation of cultural heritage to climate change is necessary to mitigate climate change impacts and to increase the resilience of historical sites. For this reason, organizations such as UNESCO, ICOMOS, IPCC, and the EC recommend more research on this topic. Accordingly, this paper analysed the perceptions of cultural heritage experts on climate change adaptation. Specifically, it reports on how climate change adaptation is considered in the management of cultural heritage sites, in scientific research and by governmental institutions and authorities working in the field of cultural heritage preservation. A common view amongst the interviewees was that adaptation of cultural heritage to climate change is possible. Opportunities for, barriers to, as well as requirements for adapting cultural heritage to climate change, as ascertained by the interviewees, provided a better understanding of what needs to be provided and prioritized for adaptation to take place and in its strategic planning. A lack of knowledge of management methodologies incorporating climate change impacts was reported albeit the interviewees were aware of a number of best practice examples in adapting cultural heritage to climate change. This paper highlights the need for more research and the identification and dissemination of practical solutions and tools for the incorporation of climate change adaptation in the preservation and management of cultural heritage.
Figure 2 summarizes the research findings.
This paper emphasized the complexity of the topic of adaptation of cultural heritage to climate change and the need for further research on this topic. Since the Paris Agreement, UNESCO has aimed to support State Parties in managing climate change impacts, however, State Parties should also collaborate and learn from each other. Adaptive measures developed in one country could be useful and adapted in another country, for instance. Hence the knowledge acquired on climate change adaptation should circulate freely and more developed countries, or countries with strategies, methodologies, measures, and more money for research, should help those that are less fortunate. This requires dialogue and collaboration, however, not only between national governments, but also between heritage organizations, institutions, research centers, heritage site managers, academics, and others involved in the preservation of cultural heritage. There is also an interrupted flow of information between the knowledge available at the international level and the passing of that knowledge down to the local management scale. Another recommendation is mainstreaming climate change in approaches used to manage cultural heritage sites, but this requires awareness of climate change impacts and hence greater dissemination as well as raising awareness of this issue to local communities and increase community engagement, as support from the wider community is important for successful adaptation to climate change. Regulations, the provision of guidelines, and financial incentives are also needed to commit organizations to climate change adaptation. Further research is needed on adaptive measures for specific heritage typologies or materials, mitigation of climate change in field of cultural heritage, and the managing of loss of cultural heritage as a result of inundation of coastal lands, for instance, risk-preparedness and the complexity of making adaptive changes to cultural heritage while also preserving heritage values.