The city of Venice overwhelmed by an exceptional flood, along with the archaeological areas of Aquileia and Ferrara. It sounds like the plot of a disaster film, but unfortunately the source is far more serious and reliable: it is the forecast of a scientific study published in the journal Nature Communications, which lists the Unesco world heritage sites that by the end of this century risk being severely damaged – or even destroyed – by climate change.

A study on artistic and cultural sites at risk

The International Union for Conservation of Nature (Iucn) had already raised the alarm: 7 per cent of natural sites classified as Unesco heritage are already in critical condition and, looking further ahead, 25% of the total could disappear.

This new research, however, is different because it focuses on places of artistic and cultural interest. More specifically, explains Science Daily, the researchers considered a series of Unesco heritage sites located in the coastal area of the Mediterranean. For each of them they recorded a series of parameters: the zone, the physical conformation, the type of settlement, the distance from the coast, and whether the setting was urban or rural.

Read also: How Unesco world heritage sites are chosen

They then assessed the possible effects of rising sea levels, developing four different scenarios for the end of this century. The most optimistic one assumes that global temperature growth can be kept within two degrees centigrade above pre-industrial levels; which would already be an achievement, given that according to the Ipcc's Special Report 15 (Intergovernmental Panel on Climate Change) we could break through the 1.5-degree barrier as early as between 2030 and 2052. In the worst-case scenario considered, temperatures will rise by 3 or even 4 degrees centigrade by 2100.

By combining these two dimensions (climate change and the characteristics of the sites), the researchers were able to estimate, for each of the Unesco sites, the consequences of two phenomena: flooding and coastal erosion.

Dozens of Unesco heritage sites could end up submerged

Of the 49 archaeological and cultural sites examined, 37 are already at risk of a "centennial" flood today, meaning one of an intensity that has a 1 per cent probability of occurring each year. 42 out of 49, meanwhile, could suffer the consequences of coastal erosion. If Mediterranean levels were to rise by 1.46 metres by 2100, the first of these risks would increase by 50 per cent and the second by 13 per cent. This scenario is currently estimated at a 5% probability but – warns Professor Vafeidis, one of the study's authors – cannot be ruled out, all the more so because there remains significant uncertainty over the process of glacier melting.

It is decidedly striking to read, one after another, the names of the historical and artistic wonders that could pay the price of climate upheaval.

First among those at risk of being submerged by floods is Venice, along with the lagoon islands. Then there is Ferrara, one of the emblematic cities of the Renaissance, together with the Po Delta area; but also Aquileia with its mosaics. Beyond Italy's borders, the medina of Susa in Tunisia, the archaeological site of Sabratha in Libya, and Dubrovnik, the jewel of Croatia, are all at serious risk.

Coastal erosion threatens several gems of our country: from the north, with the Cinque Terre and Portovenere, to the south, with the Amalfi Coast and Paestum, and extending to the gulf of Noto and Syracuse, in Sicily. This threat weighs even more heavily on the Heraion of Samos and the excavations at Ephesus, in Turkey.

But what is the solution, according to the scientists? The first is to do everything possible to protect these priceless places: climate-related disasters will increasingly become the norm, and this demands that adequate adaptation measures be put in place. The second path proposed is that of mitigation strategies, which must be adopted globally and with rigour.

Opening photo © Nicolò di Giovanni / Unsplash