**1. Introduction**

Heritage tourism represents an important nexus in which cultural heritage resources and anthropogenic climate change intersect. This is especially the case for e fforts pursuing climate mitigation and climate communication. Tourism is a major contributor to greenhouse gas emissions, and the tourism industry will require broad changes to operations in order to mitigate climate change [1–4]. In 2005, the tourism industry (including transport, accommodation, and activities) was estimated to contribute 5% of global anthropogenic carbon dioxide emissions (with aviation transport accounting for 40% of this amount, car transport for 32%, and accommodation for 21%) [5–7]. By 2013, tourism accounted for 8% of global greenhouse gas emissions, and previous reports may have underestimated the contribution [8]. Moreover, tourism is only expected to grow, with carbon dioxide emissions predicted to increase 135% between 2005 and 2035 [5–7] and international air travel projected to double in the next 15–20 years [9]. Scholars in tourism studies have turned a spotlight on global climate change [2,3,10,11], including increasingly sophisticated accounts of the carbon systems in tourism [12,13] and "carbon management" to mitigate the impacts of climate change from

tourism [1]. The impetus of our study dovetails with current research in tourism studies on climate change, but cultural heritage has rarely been the focus of such studies.

Heritage sites and resources feed the trends in the diversification and geographic expansion of tourism. Indeed, the case of heritage tourism is especially urgent, since according to some estimates it accounts for approximately half of all tourism [5,14], and it contributes to the destruction of the resources on which it is based, both presently and, considering projected climate impacts, in the future. Moreover, taking into account that heritage tourism is one of the principle means for pursuing economic development through heritage resources, the detrimental impacts of heritage tourism on heritage resources in light of climate change thus raises the question of whether the use of heritage tourism for sustainable development is viable.

At the same time, World Heritage has also been picked up by climate scientists and activists as a flashpoint for taking action on global climate change, given the impacts that climate change will have on well-known heritage sites beloved by many [15,16]. The Great Barrier Reef has attracted particular attention, as its status as a World Heritage Site (subject to international treaty law) has been leveraged to bring the Australian Government to account for its tepid response to climate change mitigation [17,18]. An explicit focus on cultural heritage in climate action and climate communication can raise in sharp relief the anthropogenic and long-term character of global climate change. Yet, as the link between global climate change and loss of WHS is made stronger in the public imagination, trends in what is called 'last chance tourism' [19–22] sugges<sup>t</sup> that WHS impacted by climate change will attract increasing numbers of visitors, to witness the WHS 'before it is gone' or irreparably changed. 'Last chance tourism' often has the paradoxical e ffect of hastening the deterioration of the site in question, for example from increasing pollution and greenhouse gas emissions from Antarctic cruise tourism [23] or the carbon costs associated with polar bear tourism in Churchill, Canada [24].

National governments and local development initiatives often pursue inscription of sites on the UNESCO World Heritage List because of its performance in attracting international tourism (the most "costly" of tourism carbon footprints) [25–29]. Indeed, the UNESCO World Heritage List has exploded to over 1100 properties and counting, overwhelming the List's original conservation mandate as national governments seek to attract foreign tourism revenue and foster economic growth through the World Heritage "brand." The branding function of World Heritage is powerful and increasingly central to motivations for inscription [30–33].

WHS around the globe hold a special resonance for the communities residing within or nearby the sites, the governments that nominate the sites at much expenditure, and the tourists and other visitors who choose a World Heritage Site as a destination worth visiting. As the world's cultural treasures, WHS elicit concern for conservation and sustainability, coupled with a well-known brand recognition. These two facets of World Heritage—conservation and branding—provide an excellent vehicle for drawing public awareness and action to the problem of global climate change. Further, while previous sustainability-oriented work on WHS has focused on "sustainable tourism" [34–36], social sustainability [37], or site sustainability [38], scholarship on the sustainability of WHS vis-à-vis climate change remains incipient, especially with respect to the contributions of World Heritage Site facilities and tourism to the production of greenhouse gases and to incorporating carbon managemen<sup>t</sup> as part of site managemen<sup>t</sup> and heritage managemen<sup>t</sup> more broadly.

The growth of the World Heritage List to over 1100 sites also tracks a sea change in heritage managemen<sup>t</sup> in global contexts more broadly, from managemen<sup>t</sup> models built around preservation and conservation to those built around economic development [39,40]. Conservation and development have been two sides of the same coin since at least the 1940s, with the rise of international cooperation over heritage resources. However, development is increasingly the raison d'être of heritage managemen<sup>t</sup> globally, as state and community interest in using cultural heritage for economic development has grown, and international development circles have adopted cultural heritage as a socially-responsive approach to development attuned to sustainability and human capabilities.

In the following we detail the development of what we call a "climate communication recognition scheme" (CCRS) for UNESCO WHS, as a tool for using heritage sites to communicate the drivers and impacts of anthropogenic climate change. The CCRS, titled *Climate Footprints of Heritage Tourism*, is available online as an ArcGIS StoryMap at http://www.heritageofclimate.com [41]. While considerations of climate change are increasingly being incorporated into heritage managemen<sup>t</sup> practices, including within WHS nominations, the focus remains on climate-related threats and impacts to heritage resources, rather than the contributions of heritage sites as drivers of anthropogenic climate change—for example from site infrastructure, tourism, and land use. We argue for the value of a more holistic response in heritage managemen<sup>t</sup> to the challenges of climate change, one that takes into account impacts alongside fostering adaptive capacity, integrating carbon managemen<sup>t</sup> practices for mitigation, and communicating climate change through the public platforms a fforded by heritage resources. Given the relative lack of attention paid to mitigation and climate communication, we focus our e fforts in the CCRS especially on these two dimensions, but impacts and adaptation are also represented.

This holistic approach that we advocate is further reflected in our decision to conceive of the category of CCRS. We describe CCRS as an extension or elaboration of ecolabels. "Ecolabels" assign labels to consumer goods (for example, organic and fair trade certification of foods) for the purpose of communicating the sustainability of a product, but they tend to be one-dimensional and quantitatively driven. As discussed below, a CCRS expands on ecolabels to provide a more holistic recognition scheme, and one that is specifically attuned to communicating climate change.

While a CCRS could be developed for any heritage site, in this study we focus on WHS to leverage the brand recognition of World Heritage—as global heritage conservator—into a "product" or platform for developing the CCRS. The value of a CCRS for heritage resources is that it o ffers another frontline for climate action, as a tool for transnational climate governance. While national governments and the international (intergovernmental) system continue to show, on the whole, weak and ine ffectual gains in reducing the drivers of climate change, the possibility of advancing climate action through transnational governance channels shows increasing promise. Through the development of a CCRS as a transnational governance tool for heritage managemen<sup>t</sup> and heritage tourism, we aim to highlight how heritage resources may be mobilized for responding to the challenges of anthropogenic climate change.

### **2. Materials and Methods**

### *2.1. Identifying a Subset of WHS for Analysis*

Recognizing the scale of the World Heritage List—composed of more than 1100 sites and with additional sites being inscribed every year—we began this study as a pilot project and needed to identify a subset of sites for analysis and development into the CCRS. We undertook a broad survey of WHS, and a subset of sites (*n* = 50) was chosen based on the following considerations: (1) most visited and iconic sites; (2) sites impacted heavily by climate change (currently or projected); (3) sites that tell important stories about anthropogenic climate change; (4) sites that have active sustainability initiatives or programs in progress; and (5) representativeness, for example in geographic distribution and site types.

Most visited and iconic sites (e.g., Angkor, the Historic Ensemble of the Potala Palace, Lhasa, and Machu Picchu) were identified through articles in media outlets such as National Geographic and through surveys conducted by TripAdvisor, a popular source of advice for travelers. These sites were included so as to increase interest in and relevance of the results of the analysis, and because as some of the most visited sites they likely generate a disproportionate share of carbon emissions from heritage tourism compared to other sites on the World Heritage List. Sites most at risk of being impacted by climate change were identified by drawing on existing studies by UNESCO World Heritage and its advisory bodies, as well as heritage experts and non-governmental organizations [18,42–45].

Attention to narrative is recognized as an increasingly vital tool for responding to the challenges of climate change [46,47]. Narratives provide conceptual sca ffolding not only for adapting to climate change and mitigating its drivers, but also for mobilizing broader conversations about the moral and ethical foundations of a changing climate, and for individually processing how we face climate change in dignity, grief, sorrow, and hope. We identified sites with the narrative potential to tell stories about climate change through a process of qualitative coding [48] of the site descriptions and site documentation for the WHS [49], and associated literature, and coded for themes related to climate change. Coding allowed us to draw out those sites that offered especially holistic (integrating facets such as impacts, adaptation, mitigation, and communication) and visible cases of the nexus of heritage and climate change, as well as themes that might not be captured in the other categories under consideration. For example, sites associated with the use of fossil fuels (e.g., Cornwall and West Devon Mining Landscape, UK) help illustrate the anthropogenic contributions of carbon-based energy sources to climate change, and sites endangered by conflict influenced by climate change (e.g., Palmyra, Syria) highlight that impacts on heritage resources are not only natural or environmental (e.g., sea level rise, increased pest and mold activity) but social too.

Sites with active sustainability practices were identified through an examination of relevant documentation from UNESCO, academic literature, and through news media coverage [50,51]. Finally, sites were added to ensure that the subset was representative of the World Heritage List, with regard to factors such as type, purpose, and geographical location.

The subset of 50 sites was then organized into four subgroups: (a) sites selected for carbon footprint analysis; (b) sites with narrative potential; (c) sites with active sustainability practices; and (d) sites most impacted by climate change (see Appendix A). Some WHS were included in more than one subgroup.

### *2.2. Calculating Carbon Footprints of Travel*

Ten sites were selected for calculating the carbon footprint of travel, chosen to ensure geographic and site type diversity. This study took a consumer-based approach, which allocates the emissions from tourism to the tourist, in recognition of the consumer-tourist as the main driver behind demand [12,13,52,53]. The consumption-based approach estimates the carbon footprint of at minimum three typical visits (budget, mid-range, and high-end spending) to each of these sites. For some sites, the carbon footprints for additional kinds of trips was calculated (e.g., cruise vs. land-based trips to the Galápagos Islands). For the purposes of this study, a typical trip was considered to be one in which a tourist traveled to a destination only to visit the WHS in question. Broad expenditure categories that make up the activities of tourists at these sites include local transport, accommodation, restaurant services, and recreation and leisure services, including heritage tourism activities. Excluded from the analysis was money spent on retail, such as gifts and souvenirs, and any expenditure related to travel to the point of departure in the tourist's home country. The data collected to build out an itinerary for the trip and calculate expenditures were collected from publicly-available websites used by travelers for the purpose of planning trips. These include WorldHeritageSite.org, the official UNESCO World Heritage website, including the individual webpages associated with each site (for identifying activities), Bookings.com (for collecting accommodation prices), TripAdvisor.com (for collecting price information for dining and additional activity costs, Google Flights (for identifying common flight paths), and the International Civil Aviation Organization (ICAO) Carbon Emissions Calculator (for calculating the carbon footprint of international flights).

The carbon footprints were then calculated using an input–output life cycle assessment (IO LCA) model. This model uses monetary transactions to approximate all of the material and energy inputs of a product, good, or service, and their direct and indirect emissions. A United States economy-based IO LCA model was used to calculate the carbon footprint of tourism to each site, due to the relative ease of gathering monetary expenditure data, the expansiveness of the model in terms of industry sectors, and the model's comprehensiveness in terms of incorporating upstream and indirect emissions in the carbon footprint (United States industry-based IO LCA 2002 Purchaser Price model). Expenditure data were assigned to one of the sectors in the model, and emissions for the total expenditure per

**Figure 1.** The average carbon dioxide equivalent (CO2e) emissions for three types of trips to selected WHS: High-End, Mid-Range, and Budget. For reference, 100 kilograms of CO2e emissions is equivalent to the carbon sequestered by growing 1.7 tree seedlings for 10 years [54]. For some sites in the CCRS we calculated multiple kinds of trips for each type (for example, multiple mid-range options using different forms of transportation), but in the above graph we have averaged these in the relevant expenditure category (High-End, Mid-Range, or Budget) to simplify the graphical representation.

To improve accuracy, this model was combined with directly calculated emissions data for international flights, using the ICAO Carbon Emissions Calculator [55]. This calculator employs industry averages for the various factors that contribute to the carbon footprint of air travel. It takes into account passenger load factors, passenger-to-cargo ratios, and fuel consumption and calculates an average fuel burn per economy class passenger. The IO LCA results were added to the ICAO international air travel results in order to calculate the total carbon footprint of each type of trip to the WHS, presented in kilograms of CO2e/trip (for an example of one site, depicting travel to Machu Picchu, see Figure 2).

It should be noted that the model used in this study is limited in its ability to accurately calculate emissions based on non-U.S. dollar expenditures, and expenditures were adjusted for inflation from 2002 to 2018. We therefore emphasize that the result is an estimated carbon footprint, used for educational purposes only. Unlike ecolabels, the recognition scheme developed here does not aim to provide rewards or certification to particular sites with lower carbon footprints, nor does it aim to set standards for carbon emissions. The recognition scheme uses carbon footprint information to provide information to the public about the potential general consequences of their travel, in an effort to increase consideration of climate effects.

**Figure 2.** Carbon dioxide equivalent (CO2e) emissions generated in a round-trip flight from a representative airport city in each country to Cusco, Peru, for the purpose of visiting Machu Picchu.

### *2.3. Collecting Additional Climate Information*

In order to address the narrative potential presented by sites in this subgroup for climate change communication, a list of a priori themes were developed that may be applied to coding site documentation. Documentation such as advisory body evaluations, media articles related to the site, site managemen<sup>t</sup> plans, UNESCO mission reports, periodic reporting by the State Party, and other relevant reports were collected from the UNESCO website and other web sources. These were analyzed using NVivo 12 through a directed approach to content analysis [56]. As analysis proceeded, additional themes arose, and some themes were combined to clarify patterns. The final list of themes addressed topics such as conflict, education, environment, climate change impacts, biodiversity, industrial heritage, public engagement, sustainable development, and transnationalism. Patterns amongs<sup>t</sup> the data were then drawn out and used as a framework for a brief narrative about how best to draw a visitor into a story about climate change at the site.

Identification of sustainability practices took place through reviews of site documentation, work conducted by UNESCO and other researchers, and news media. Sustainability measures considered include, for example, aggressive action towards increased use of renewable energy, acknowledgment of the importance of energy audits and reducing energy use, and embracing renewable energy at the beginning of electrification projects.

Climate change impacts were identified through reviews of site documentation, UNESCO reports, news media, and academic work. Vulnerabilities to climate change and previously-recorded impacts of climate change on sites were documented. These focused on the physical, direct impacts of climate change on the site. Damage caused by conflict related to climate change was not included in this section (but was considered for the narrative potential of sites).
