Among all the rankings that periodically tell us about places to visit, this is perhaps the one we like least. It warns us of 50 places — glaciers, lakes, forests, cities — that climate change and pollution risk erasing or transforming beyond recognition within just a few years. This is how "last-chance tourism" was born: what to see before it's too late. Many of the places we know and take for granted, we may never get to visit, unless there is a decisive and immediate shift in global environmental policy.

Among the destinations flagged is our own Venice: it has been considered a city at risk for a long time — perhaps always — but last year La Serenissima was added by the World Monuments Fund (Wmf) to its list of the 67 most at-risk historic and archaeological sites of global significance. This is due to many factors: the progressive erosion of the lagoon, the continual rise in sea levels, but also uncontrolled tourism, the proliferation of large ships in the San Marco basin, and a population decline that has reached 50% over the past ten years.

Some of these causes are evidently dictated by the nature of the city itself, others by the economic interests that Venice generates: on the one hand, for example, it would be desirable to reduce cruise ship traffic in the lagoon, while on the other we know that many see such measures as a reduction in tourist numbers and earning potential.

Perhaps the only thing worth focusing on — the true priority — is preserving the uniqueness of Venice, upon which a form of tourism has been inflicted that is entirely incompatible with the specific character of the world's most important art city: an artistic and cultural heritage that belongs not only to our country but to all of humanity, and which is under constant threat.