St Kilda: How climate change is threatening remote Scottish archipelago and dual World Heritage Site

One of Scotland’s most breathtakingly beautiful natural and cultural assets faces growing risks as climate change hits home, experts warn

Wilder and more frequent storms, changing ocean currents and warming temperatures are taking an increasingly heavy toll on one of Scotland's most remote and spectacular scenic outposts, posing a growing danger to both nature and culturally important buildings.

A new report has identified the three biggest threats facing St Kilda – the westernmost islands of the Outer Hebrides and the UK’s only dual World Heritage Site – as a result of climate change. The Climate Vulnerability Index uses past and predicted environmental changes at United Nations World Heritage Sites to assess how these globally significant places will be affected in future.

St Kilda is a jagged volcanic archipelago made up of the islands of Hirta, Dun, Soay and Boreray, located 40 miles from South Uist – the nearest land. It has some of the highest cliffs in Europe and is home to large colonies of rare and endangered seabirds – more than a million at the height of the nesting season – especially puffins and gannets.

The location also hosts unique wildlife, including a mouse and a wren found only there, and has its own distinctive local sheep breed.

Although uninhabited since 1930, when the final 36 St Kildans were evacuated to the mainland at their own request, the islands bear evidence of more than 2,000 years of human occupation. Remains include traditional stone-built houses and remnants of a way of life based on the products of birds, agriculture and sheep farming.

St Kilda, which is cared for by the National Trust for Scotland, is the only place in the UK to be designated as a World Heritage Site for both its natural and cultural importance. But it is exposed to the elements in a way that is distinct from all other UK World Heritage Sites.

Susan Bain, the National Trust for Scotland’s property manager for St Kilda, said caring for the islands was “a huge task” for the conservation charity, but environmental factors would make the job even harder and could even hamper the ability of workers and tourists to get there.

The remote St Kilda archipelago, now officially uninhabited by humans, is the only UN World Heritage Site in the UK to be designated for both is natural and cultural importance

She said: “We have certainly been experiencing the effects of climate change on St Kilda for decades, with the impacts on some of the seabird species and marine habitats being particularly profound. This report tells us that in the future we will have more and more challenges to manage, and it will be increasingly difficult to do so.

“Warming sea temperatures are already impacting on the food chain for the hundreds of thousands of seabirds who breed here each summer, and some species are at risk of disappearing from St Kilda forever.

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“Changing currents could compound this even further, fundamentally changing the habitats and with that the types of birds that can thrive here.

St Kilda, made up of the islands of Hirta, Dun, Soay and Boreray, is located 40 miles from South Uist – the nearest land

“The risk of increasingly ferocious and frequent storms not only puts the unique built heritage of St Kilda at risk of more damage, but also makes it practically more difficult to get our dedicated staff and volunteers out there to carry out our vital conservation work.”