According to a report in The Observer, the warning was issued by researchers from the National Trust, UK.
The places that could alter dramatically are the castle of St Michael's Mount off the coast of Cornwall, the white cliffs of Birling Gap in East Sussex, Studland beach in Dorset and the dunes of Formby, near Liverpool.
In one of the most extreme cases to be identified by the trust, the entire 18th-century fishing village of Porthdinllaen on the north-west coast of Wales could be left to crumble into the sea.
The report on the 10 coastal hotspots will be published this week to highlight the problems of climate change that threatens about 70 sites around the coastline owned by the trust.
Phil Dyke, the National Trust's coast and marine adviser, said that the decision to stop protecting many coastal areas was driven by the rising cost of damage, because global warming is causing more sea-level rises and more intense storms which exacerbate erosion, and because protection measures often cause damage farther along the coast, for example, depriving nearby beaches of shingle and sand.
On one site in Cornwall, the trust estimated it would cost 6 million pounds to build defences that would only last about 25 years.
The report highlights the difficult decisions which will have to be taken across Britain and around the world as landowners and governments decide how to cope with the impact of climate change on habitats and built infrastructure, particularly after a tradition of pitting engineers against natural change.
"Over the next 100 years the shape of our coastline will change, and our favourite seaside destinations may not look the way they were captured in our holiday snapshots," said Dyke.
"I think we have a natural affinity with our coast and the sea. But we all need to be aware that our environment is not fixed and that change is inevitable," he added.
Some of the risk areas identified are the puffin and seal colonies on the Farne Islands off the Northumberland coast; the shingle spit of East Head at the entrance to Chichester Harbour in West Sussex, which will also affect nearby West Wittering beach, and, Dorset's Studland beach, which is visited by more than one million people a year.