At a Glance

Forty-seven of 49 UNESCO World Heritage sites near the coast in the Mediterranean are threatened by climate-driven rising seas and erosion.Fifteen sites were at risk in Italy, the most out of any country in the region. The flood risk across the region is projected to increase by 50 percent by the year 2100.Coastal erosion is expected to increase by 13 percent.

Nearly all of the UNESCO World Heritage sites located in coastal regions of the Mediterranean Sea are threatened by climate-driven rising seas and erosion, a new study says.

According to thein the journal Nature Communications,47 of the 49 historically and culturally significantsites that dot the rim of the Mediterranean Sea are in danger.All are locatedin the Mediterranean LowElevation Coastal Zone and are no more than 33 feetabove sea level.

Overall,Italy had the greatest concentration of imperiledsites at 15, followed by Croatia with seven, Greece with fourand Tunisia with four.

Italy's Venice, the Patriarchal Basilica of Aquileia andFerrera, City of the Renaissance and its Po Delta are among the sites most at risk from flooding, the study says.

"These World Heritage Sites are located along the northern Adriatic Sea, where extreme sea levels are highest as high storm surges coincide with high," the authors said in a press release.

The sites most at risk from coastal erosion include Tyre in Lebanon, the Archaeological Ensemble of Tárraco in Spainand Ephesus in Turkey.

Only theMedina of Tunis andXanthos-Letoon in Turkey will not be threatened by either sea level rise or erosion by the turn of the century, the researchers say.

(MORE:)

The flood risk from rising seas across the region is projected to increase by 50 percent by the year 2100, the study notes, while coastal erosion is expected to increase by 13 percent.

Unless humanity takes immediate action to curb carbon emissionsthe47 imperiledsites could be lost because there are few options for protectingthem from rising seas and erosion, the authors warn.

Onlythe Early Christian Monuments of Ravenna in Italy and the Cathedral of St. James in Croatiacould be relocated if need be. However, moving the sites wouldcompromise what UNESCO calls their "outstanding universal value."

The researchers looked at four different climate change scenarios using different rates of warming and ice sheet melt. The warming ranged from the Paris Agreement target of 2 degrees Celsius above pre-industrial levels to 3 to 4 degrees Celsius by 2100. Even under the most optimistic of scenarios, the vast majority of the sites remained at risk.

There are 1,092 sites on the. Of those, 845 are cultural, 209 are natural and 38 are mixed. UNESCO says 54 sites are currently in danger.

Last year, a report released during U.N. climate talks in Bonn,Germany, said the number of UNESCO Natural Heritage sites imperiled by climate change had nearly .

The natural sites that include coral reefs, glaciersand wetlands had, meaning one in four UNESCO natural sites are at risk, up from one in seven.