| Culture under climatic threat
Blackening of Milan Cathedral
The Noah’s Ark project takes as its premise that changes in the European climate over the coming century will have a range of effects on historic buildings – from old medieval churches to large iron structures like the Eiffel Tower. While the impact on individual processes (like saltwater corrosion) are well-known, the overall risk posed by climate change is less clear.
It is for that reason that the Noah’s Ark project was created. The ten-team partnership, led by Professor Cristina Sabbioni of the Institute of Atmospheric Sciences and Climate, was set the following tasks: determining the meteorological factors most critical to Europe’s historical buildings; predicting how climate change will modify these factors and what impact these will have on the buildings; and developing adaptation strategies for those cultural treasures at risk.
The project consortium consists of ten partners, including six public research institutions, two UK universities, one company (the Ecclesiastical Insurance Group, EIG) and one SME (Biologia y Medio Ambiente, BMA)*. All the consortium members are experienced in cultural heritage, including the School of Environmental Sciences at the University of East Anglia (UEA), which also familiarised the group with climate change research and provided the prediction model. From the outset it was a challenge for the cultural heritage team members to move from analysing past damage processes to predicting the impact of future climate.
The project pinpointed a number of climate change factors that were likely to impact on various building materials (stone, bricks, wood, glass, and metals). “We quickly realised we would have to develop our own cultural heritage climatology,” said Professor Sabbioni. While conventional climate change focuses on rising temperatures, for example, these are expected to have only a relatively small impact on buildings.
Instead it is the changing water cycle that may prove most critical. Increased precipitation in northern Europe could adversely affect stone and wood. In the south, meanwhile, reduced humidity will lead to a build up in salt deposits, which can also cause deterioration. And that is only accounting for gradual climate changes – increased floods and landslides will doubtless cause much damage as well, and the effect of rising sea levels on coastal erosion has been barely investigated.
In addition, the project focused on non-climate variables like pollution (for example, changes in acid rain and their corrosive impact on metals) and biodiversity. The latter was particularly difficult, since no systematic database exists on biodiversity in cultural heritage sites. In addition, biodiversity does not automatically equate with building preservation: some species harm while others protect. The consortium therefore decided to focus on lichen species, and the various roles they have in biodeterioration and bioprotection.
Expected annual heavy precipitation in the far future (dark blue = more than18 days)
The last year of the project saw the consortium focus on how to present the results, to their primary audience of policymakers and cultural heritage managers. The answer they came up with was the Vulnerability Atlas. Maps were created of the recent past (1961-1990), near future (2010-2030) and far future (2070-2099), outlining the prevalence of each risk factor across Europe, and an additional map shows the predicted change.
Professor Sabbioni admitted that the resolution of these maps are too low to be meaningful, especially for cultural heritage managers concerned with their own specific building. They do, nonetheless, provide a stark illustration of the dangers posed by climate change. The next stage of research should therefore be about re-linking the global to the local: increasing the data and enhancing the monitoring instruments to allow for a greater deal of precision.
The final report also provides guidelines for adaptation. Each threat – from stone blackening to fungal threats to wood – are dealt with, with suggestions of what policymakers and cultural heritage managers should be doing to save their buildings. These end-users can therefore plan their conservation efforts based on which risk factors threaten their area.
The project has received unprecedented media coverage, from the USA to Australia. While Professor Sabbioni remains modest about the results, insisting it raises more questions than answers and provides only a framework for future result, the Noah’s Ark project should be lauded at the very least for achieving this: bringing the threat to cultural heritage into the climate change debate and raising the importance of our culture to sustainable development.
* This is the list of participants in the project:
1. Istituto di Scienze dell'Atmosfera e del Clima - CNR, Bologna, Italy
2. UCL - Centre for Sustainable Heritage - The Bartlett School of Graduate Studies, London, United Kingdom
3. University of East Anglia - School of Environmental Sciences, Norwich, United Kingdom
4. Corrosion and Metals Research Institute - KIMAB, Stockholm, Sweden
5. Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Krakow, Poland
6. Institute of Theoritical and Applied Mechanics ASCR, v.v.i., Prague, Czech Republic
7. Instituto de Recursos Naturales y Agrobiologia, Sevilla, Spain
8. Norsk Institutt for Luftforskning, (NILU), Kjeller, Norway
9. Ecclesiastical Insurance Group plc, Gloucester, United Kingdom
10. Biologia Y Medio Ambiente S. L., Barcelona, Spain