How does climate change affect world heritage sites?

The vast majority of World Heritage Sites (WHSs) in the Mediterranean are already at risk of irreparable damage due to manmade climate change, according to a new study. The findings, published in the journal Nature Communications, analysed 49 locations in Europe and the Middle East and found over 75% of them to be in danger of rising sea levels and coastal erosion. Even more concerningly, that percentage is only projected to rise as time marches on. Unless swift and definitive action is taken to limit our carbon and methane emissions, wonders such as the ancient city of Carthage or the Leaning Tower of Pisa could soon become confined to the depths of the ocean and the annals of history alone.

The research was conducted by a team of scientists from Kiel University in Germany and focused on 49 UNESCO heritage sites in and around the Mediterranean Sea, each of which is located no more than 10m (33ft) above sea level. The country with the most at-risk sites was Italy with 15, while Croatia had seven and both Greece and Tunisia had four.

By using sophisticated computer modelling technology, the team were able to predict what would happen in four different scenarios depending on how our greenhouse gas (GHG) emissions vary over the period from the year 2000 to 2100. Unfortunately, even the most optimistic model showed that the majority of sites are already under threat.

37 of 49 WHSs included in the investigation are already at risk from flooding caused by rising sea levels, with that figure projected to reach 40 in the most pessimistic projection. 42 of the 49 are already threatened by coastal erosion, and all but two (Xanthos-Letoon in Turkey and Medina in Tunisia) are expected to be at risk by the turn of the century.

Venice in Italy, nicknamed the Floating City, is believed to be most at risk from flooding due to its world-famous networks of canals. Indeed, Venice became inundated almost 10 years ago after heavy rains and high winds struck it in December 2008, while late last month, more inclement weather led to around 75% of the city becoming submerged. The experts behind the most recent research say that figure could rise to 98% if a once-in-a-century-strength storm were to hit it.

Meanwhile, the Lebanese city of Tyre - once the capital of the ancient civilisation of Phoenicia - is the most at-risk from coastal erosion. With its location on the Mediterranean coast, the heavy sand composition of its soil and the high waves which strike it (regularly reaching up to 0.7m or 2.3ft), Tyre is at grave risk of irreparable damage. Pythagoreion and Heraion of Samos, an ancient architectural site dedicated to Hera, is next on the list of vulnerable hotspots.

While modern science is continually developing better and more sophisticated ways to anticipate extreme weather events (the recent dry spells which plagued Europe were predicted over six weeks in advance, for example), more affirmative action is needed to limit the effects of global warming. Otherwise, these stunning marvels of the ancient world - and the tourism revenue they bring with them - could soon be a thing of the past.