Rising sea levels from global warming is a serious risk to thousands of neolithic monuments on the islands of Orkney, according to a new report.

Architectural Design magazine said historic sites such as stone houses, Viking tombs and the settlement of Skara Brae could all be destroyed as rising water levels accelerate beach and cliff erosion.

The warning comes after the publication of the 2018 Arctic Report, published by the National Oceanic and Atmospheric Administration, which said rapid warming over the past three decades had led to a 95 per cent decline in some of the oldest and thickest ice sheets.

As a consequence, many coastal areas are at increased risk of flooding, storm surges and erosion.

Meaghan O’Neill, author of the Architectural Design report, said: “The heart of neolithic Orkney, with roughly 3,000 neolithic monuments, represents some of the world’s oldest-known structures. Many were constructed before Stonehenge or Egypt’s pyramids.

“These stone houses, Norse halls, and Viking tombs have survived here for 5,000 years, but now, eroding beaches and cliffs threaten to destroy about half of them.”

John Ross Scott, councillor for Kirkwall, said Orkney Council was treating the threat very seriously, but needed extra funding from the Scottish Government to help with preservation efforts.

He said: “At a council level, we are listening and responding, as we can, to the ever-increasing threat of rising tides.

“However, funding the measures required to protect the sites will require central government finance.

“There are current emergency issues on the islands of Sanday and Rousay where archaeologists are trying to save artefacts before the sea takes them.”

Mr Scott said archaeologists were working as part of the Northern Exposure project, managed by the University of the Highlands and Islands, to examine villages abandoned in 2400 BC at the end of the Neolithic period.

Mechtild Rossler, director of UNESCO’s World Heritage Centre, said losing ancient sites had a very significant impact on future generations.

He said: “Such losses do not only concern the disappearance of some of the most exceptional sites on the planet.

“They also affect people’s link to the past, their identity, their resilience, and our collective knowledge.”

He added that losing UNESCO World Heritage sites such as Skara Brae and those in low-lying areas in the heartland of Orkney, would be a “dramatic loss for humanity”.

The latest warnings come after a 2016 recent report by a campaigning group the Union of Concerned Scientists said many of the sites on the Orkneys were under threat due to climate change.

Scotland’s Shetland Islands are also struggling with threats from rising tides.

Coastal erosion is not a new phenomenon on the Orkney Islands. In 1927, a sea wall was built to protect Skara Brae.

However, the pace of coastal erosion has doubled since the 1970s, and formerly protected coastline areas are now experiencing erosion for the first time. In a few cases, authorities have erected barriers to slow the erosion, but these may only be a temporary solution that could preserve the sites for a few more generations.

Other sites around the world that are at risk from coastal erosion include Easter Island, with its famous head statues, many of which are situated close to the sea, he said.

Elsewhere sites which bring in important tourism revenue could be particularly badly hit, such as Uganda’s Bwindi Impenetrable National Park where rising temperatures could affect the habitat of endangered mountain gorillas.