Its authors say 31 natural and cultural world heritage sites in 29 countries have been identified as affected by climate change. The impacts include rising temperatures, higher sea levels, more extreme weather, and fiercer droughts.
The report by the UN Educational, Scientific and Cultural Organisation (UNESCO), the UN Environment Programme and the Union of Concerned Scientists says climate change is rapidly proving to be one of the most significant risks for world heritage sites.
In an ironic twist, one of the sites the report lists is a national park on Rapa Nui (Easter Island), 500 km west of Chile. It faces water shortage, sea level rise and coastal erosion.
Some scientists have suggested that the collapse centuries ago of the island’s civilisation was caused by human over-exploitation of its resources.
The report says climate change is a major threat to some of the world’s most popular tourist attractions, to the tourism industry itself, and to the entire economies of some countries which are home to the sites.
It says tourism, one of the world’s largest and fastest-growing economic sectors, generates 9 percent of the world’s gross domestic product and provides one job in every 11 globally.
But the authors warn that unplanned or poorly managed tourism is itself a separate threat to many heritage sites.
They list some of the climate threats to the sites, including damage from extreme wind and rainfall, coastal erosion, flooding and increasing damp. Changes in soil moisture destabilises building foundations, and thawing permafrost can cause problems for Arctic sites.
Humidity causes mould, rot and insect infestations inside buildings. In the open air, earthen architecture is at particular risk, and many such sites – for example, the Djenné mosque in Mali, West Africa – are in jeopardy.
Rising sea levels in the Adriatic have already damaged hundreds of buildings in Venice.
In 2012, Hurricane Sandy raised wave heights in New York Harbour to a record 9.91 metres, and the Statue of Liberty, the report says, faces a drastically increased risk from future storms, although Sandy was judged to be a once-in-700-years event.
But while $100 million has been allocated to protecting the statue and its surroundings, and work to protect Venice costing $6 billion is nearing completion, the amount available to the World Heritage Fund totals $4 million – a drop in the ocean, the authors say, to support a thousand sites.
The report includes a number of recommendations. One, which could be valuable more widely than to heritage and tourism alone, is to make sure we learn the lessons of the past while we can.
It urges scientists to “analyse archaeological data and cultural heritage to use what can be learned from past human responses to climatic change to increase climate resilience for the future”.
But it warns that there’s little time to lose: “Some of the archaeological resources that can provide insights for our future by opening windows on the past are in danger of being lost, particularly in rapidly warming Arctic regions and along eroding coastal and riverine sites.”