Impact of Climate change on Flemish built heritage and actions required from the heritage sector and authorities

NATHALIE VERNIMME
Flemish Heritage Institute

According to the European Environment Agency, the main expected changes as a result of climatic change are: an increase by 1.4 to 5.8° C by 2100 in global mean temperatures; an intensification of the hydrological cycle, with increased intensity of rainfall events, but at the same time more frequent droughts in arid and semi-arid areas; an increase in global sea level of 0.09 to 0.88 m by 2100 and an increased frequency of storm surges locally.

There exists currently no detailed study of how this climate changes will affect the built heritage in the low countries. It is a fact that rising sea levels could threaten in the future thousands of monuments along our coastlines, but the heritage is now already heavily under pressure and not only due to climate change: we have seen the last decades a lot of damage as result of a combination of several causes (such as traffic, industry, cultivation of the soil etc.)

Heavier rainfall and changing humidity levels for example take a heavy toll from our cultural treasures. The climate change results in lower humidity during the summer and this increases the amount of salt deposited. This is especially dangerous for Flanders churches and Gothic cathedrals, whose elaborate carvings are made in soft porous stone which absorbs sea salt present in liquid form in the air's moisture. Once the water evaporates, the salt crystallizes and puts pressure on the surrounding stone with unrepairable damage as result. Increases in storminess and wind gusts also leads to structural damage of historic buildings. Timber and other organic building materials are more often attacked by insects, moulds, fungi and invasive species such as termites. Corrosion of stained glass windows occurs etc..

This lecture tries to illustrate the actual situation in Flanders with some case studies. Also the lecture emphasizes the urgent need for monitoring, preventive maintenance and interdisciplinary research to support decision making and emergency preparedness.