Vulnerabilities

Cultural heritage includes both tangible and intangible heritage. Tangible heritage includes historic environments, buildings, structures, objects, materials or fabrics, and archeological sites and remains. Intangible heritage includes cultural landscape, traditional knowledge, and cultural identity (10).

Climate change may affect our cultural heritage. Impacts typically include sea level rise; flooding; coastal erosion; changing air and sea temperatures; changing humidity; extreme weather events such as hurricanes, storms, and droughts; weathering; and changing soil and sediment conditions (11). A comprehensive understanding of the impacts of climate change on cultural heritage is noticeably absent from the literature, however. A first global systematic literature review of the link between cultural heritage and climate change was published recently (10). This review shows that the earliest research paper on climate change-induced impacts on cultural heritage was published in 2003. Since then, the annual number of publications of climate change and cultural resource and heritage research increased significantly. Remarkably, the highest number of publications globally on this subject is related to European contexts (59%). Far less publications focused on other continents: North America (17%), Australia and Oceania (11%), Asia (10%), South America (2%), and Africa (1%). Nearly half of the European studies are related to cultural heritage and resources in Northern Europe, with the majority referencing the United Kingdom (10).

The global literature review highlights important knowledge gaps in the reviewed publications. First, more research is needed on efficient short- and long-term sustainable adaptation planning that mitigates damage and enhances preservation of non-renewable cultural heritage and resources. Secondly, emphasis is needed on the capacity of cultural heritage and resource managers to prepare for and deal with the consequences of climate change. Clearly, it takes considerable coordinated effort to manage, preserve, and adapt cultural heritage and resources under climate change (10). 

Underwater cultural heritage

Underwater cultural heritage (shipwrecks, for instance) is well protected under the water. At the seafloor, the current speeds are often very low, with minimal tidal effects and sediment transfer rates. Cold temperatures and currents in a deep-water environment have a strong preservative effect. As a consequence, shipwrecks are often situated in the ideal conditions for preservation (13). It is only when objects are disturbed that the equilibrium due to burial is lost (14). For this reason, leaving heritage in situ is usually archaeologists’ first option for preserving heritage in both land and underwater sites.

Climate change may affect underwater cultural heritage such as shipwrecks in four ways (12):

1. Through the warming of ocean water. (1) Chemical changes. Any chemical change occurs faster at a higher temperature. As a consequence, the deterioration of heritage due to chemicals in seawater will occur at an increasing rate. (2) Increasing water temperature could be crucial in aiding shipworms to adapt to lower salinity.
2. Through changes in ocean currents. Currents may move sediments and thus reveal shipwrecks that used to be protected by the sediments.
3. Through chemical changes of ocean water. A variety of chemical changes might occur in the oceans as a result of climate change, including changes in acidity and salinity. When seawater becomes more acidic, underwater material is more likely to corrode, and archaeological textiles remaining under water may be lost. Salinity also accelerates corrosion.
4. Through sea level rise 

Worldwide sea level rise impacts in the next 2000 years

Summary IPCC (2014)

There is evidence to suggest that climate change and sea level rise will affect maritime heritage in the form of shipwrecks and other submerged archaeology (2). Surface recession on marble and compact limestone will be affected by climate change (3). Marble monuments in Southern Europe will continue to experience high levels of thermal stress (4) but warming is likely to reduce frost damage across Europe, except in Northern and Alpine Europe and permafrost areas (Iceland) (5). Damage to porous materials due to salt crystallisation may increase all over Europe (6). In Northern and Eastern Europe, wood structures will need additional protection against rainwater and high winds (7).

UNESCO sites

The impact of global warming on the cultural world heritage through sea level rise has been estimated for the next 2000 years (1). A time scale of 2000 years is short enough to be relevant for the societal discussion on climate change with regard to the cultural heritage, since a number of UNESCO sites are as old as or older than 2000 years. There are 720 sites listed in the cultural and mixed categories in the UNESCO World Heritage List (obtained in October 2012). Mixed sites are sites of both cultural and natural significance.

If the current global mean temperature was sustained for the next two millennia, about 6% (40 sites) of the UNESCO sites will be affected, and 0.7% of global land area will be below mean sea level. These numbers increase to 19% (136 sites) and 1.1% for a warming of 3 K. The spatial distribution of UNESCO cultural heritage sites, of population, and of the countries impacted most by future sea level rise is such that the percentage of the cultural world heritage impacted by sea level rise is significantly greater than the percentage of land surface below sea level (1).

There are some limitations to this study, though. Only changes in local mean sea level have been considered, while episodic flooding will already impact sites at lower sea level rise, especially if storminess, and thereby sea level variability, increases. Furthermore, adaptation measures like dike building have not been considered; the results merely illustrate the adaptive pressure caused by future sea level rise (1).

Adaptation strategies: opportunities and barriers

45 experts from the UK, Italy and Norway were interviewed the adaptation of our cultural heritage to climate change. These interviews were complemented with an analysis of the grey literature and an expert’s workshop. Focus was on the immovable and tangible cultural heritage, for example, historical buildings, monuments, and archaeological sites. Both the opportunities for, and barriers in adapting our cultural heritage to climate change were inventoried (15).

Opportunities for adapting our cultural heritage to climate change

One of the main opportunities is to move from reactive to proactive adaptation. Reactive adaptation means we respond to the impact of a climatic event that has already been experienced, for instance a severe storm, landslide, or flood. This often results in short-term planning and may not increase the resilience of the site to future events. Proactive adaptation takes place before the occurrence of a climatic event, focused on projected changes in climate, thereby allowing more time for consultation, the discussion of alternatives, and long-term planning (15).

In this respect, it is important to strengthen the monitoring and maintenance of cultural heritage. The monitoring of climatic conditions and of changes in the condition of heritage assets through surveys, for instance, also creates a baseline dataset against which the impacts of projected changes in climate can be estimated (15).

Barriers in Adapting Cultural Heritage to Climate Change

One of the barriers is the uncertainty of climate change projections, the impacts of climate change, and the effectiveness of the adaptation solutions to deal with those impacts. Another barrier is the fact that some of our cultural heritage will probably be lost as a result of climate change. This is particularly the case in coastal regions affected by coastal erosion and in regions with melting permafrost. A catastrophic impact would be permanent inundation of coastal heritage cities and sites as a result of sea level rise (15).

Adaptation may also be complicated because it requires a case-by-case approach. Some adaptation solutions might sacrifice heritage values or affect the authenticity of the site. Moving the heritage site due to its location on an eroding coastline, for instance, inevitably puts the heritage site out of context, thereby affecting its authenticity. And, of course, lack of financial resources is another barrier. Institutions and managers in charge of the preservation of cultural heritage sites do not have sufficient financial resources to undertake all required adaptation efforts. It is impossible, for instance, to move all the archaeological sites at risk from coastal erosion (15).

Best practices

From these interviews the following best practice examples in managerial and decisional adaptation to climate change were assembled: 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. 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 (15).

Adaptation strategies: archaeological sites

Climate change will unavoidably affect the archaeological heritage, through temperature increases, changes in humidity cycles, and increased frequency and severity of extreme events. The main players on the international scene that focus on the protection of world heritage sites are UNESCO and ICOMOS. UNESCO is one of the leading international organisations acting for the safeguard of cultural and natural heritage sites all over the world. Associated with UNESCO is ICOMOS, the International Council on Monuments and Sites, an international non-governmental organization to promote the conservation, protection, use and enhancement of monuments, building complexes and sites (8).

UNESCO and ICOMOS have drawn up recommendations on how to adapt archaeological heritage to climate change. These recommendations include the assessment of the impacts of climate change through monitoring and vulnerability assessment, and the increase of the resilience of heritage sites by reducing non-climatic sources of stress, re-designing boundaries and buffer zones, and preventive draining. Practical actions on archaeological sites can include backfilling of excavated sites and covering heritage with shelters or coatings. In addition, research, training and education, and awareness raising is needed to achieve ‘some degree of adaptation to climate change' (8).

Adaptation can reduce some of the adverse effects of climate change on archaeological sites, and can produce ancillary benefits, but cannot address all possible sources of damage. It has been recognised that it will not be possible to retain everything, and that ‘hard choices will need to be made about what to try to preserve and what to let go’ (9). It has also been recognised that response to climate change needs to cater for not only extreme events, but also gradual changes, and that climate change could present opportunities as well as threats. 

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Europe.

1. Marzeion and Levermann (2014)
2. Björdal (2012), in: IPCC (2014)
3. Bonazza et al. (2009a), in: IPCC (2014)
4. Bonazza et al. (2009b), in: IPCC (2014)
5. Grossi et al. (2007); Sabbioni et al. (2008), both in: IPCC (2014)
6. Benavente et al. (2008); Grossi et al. (2011), both in: IPCC (2014)
7. Sabbioni et al. (2012), in: IPCC (2014)
8. Cassar (2016)
9. ICOMOS (2009), in: Cassar (2016)
10. Fatorić and Seekamp (2017)
11. Brimblecombe et al. (2011); Daire et al. (2012); Gomez-Heras and McCabe (2015); Leissner et al. (2015); Liu et al. (2010); Reeder-Myers (2015); Ronco et al. (2014); Wang (2015), all in: Fatorić and Seekamp (2017)
12. Perez-Alvaro
 (2017)
13. Willis (2008), in: Perez-Alvaro
 (2017)
14. Piechota and Giangrande (2008), in: Perez-Alvaro (2017)
15. Sesana et al. (2018)