A recent study published in the journal of Nature has warned that many UNESCO World Heritage sites are under severe threat of coastal erosion and flooding due to rising sea levels within the next 100 years. The study presents a risk index that ranks the sites according to the threat they face from today until the end of the century. 

The sites featuring highest on this index in current conditions include Venice and its Lagoon, Ferrara, City of the Renaissance, and its Po Delta and the Patriarchal Basilica of Aquileia, according to researchers from Kiel University in Germany. Other sites include, the Leaning Tower of Pisa and the Medieval City of Rhodes and sites located along the northern Adriatic Sea in Italy where extreme sea levels are the highest because high storm surges coincide with high regional sea-level rises. 

The study is very interesting as it combines model computer simulations with world heritage site data to assess the risk of both coastal flooding and erosion due to sea level rise at 49 UNESCO coastal Heritage sites by the end of the century.  The researchers reported that of the sites, 37 are at risk from a 100-year flood event (a flooding event which has a one per cent chance of happening in any given year) and 42 from coastal erosion today. 

By the next century flood risk may increase by 50 per cent and erosion risk by 13 per cent across the region. The Mediterranean region has a high concentration of UNESCO World Heritage Sites because of the historical reasons, and many of these sites in coastal locations. Rising sea levels pose a great threat to these sites as the steep landscape and small tidal range in the area has meant settlements and towns were built often located close to the waterfront. 

At this time, the researchers believe that more information on the risk at a local level is needed and the approaches to adaption and protection could vary across the region due to large social and economic differences between Mediterranean countries.