Geologists take the long view, which can lead to some striking thoughts, and here is one: Britain is shrinking. As the waves crash onto the shores of this island, the rock is worn away or falls off in chunks, and, as the adage goes, they are not making land any more in Britain.

I spoke to Prof Rob Duck, at Dundee University, whose new book is called This Shrinking Land: Climate Change and Britain's Coasts. He reeled off some of the places most at risk from erosion: the coast near Hull, north Norfolk and parts of Suffolk and the Wirral. In places, up to seven metres of coast is being lost each year. Landslides also dump land into the sea, with places at risk including the Isle of Wight and Devon, he said.

Duck has a sobering message: "The defend-at-all-costs mentality can't be maintained. I think economics will mean that less populated areas will have to be abandoned in the next two decades. My book attempts to explain the underlying processes, the inevitability of erosion."

"I'm not underestimating the emotional impact – people will lose generations of memories, as well as houses," he said. "There is a price you pay for living on an island and there will be winners and losers."

We also spoke about tsunamis and the UK, two things usually assumed not to coincide. But Duck said that 5,500 years ago, the Storegga landslide on the Norwegian coast triggered a giant wave that engulfed Orkney and Shetland, as well as hitting the eastern coasts of both Scotland and England.

The tsunami has been estimated at 20m high at Orkney and probably inundated Dogger land, now permanently below the ocean. More recently, said Duck, there was a major surge in the Bristol Channel in 1607, which caused extensive flooding and killed 3,000 people. It may have been triggered by an earthquake off southern Ireland.

Lastly, and better known is the location of a tsunami yet to happen: the giant volcano that form the island of La Palma in the Canaries. "If the western flank comes off it would send a tsunami straight at south west England," said Duck.

The fact that tsunamis can happen in the UK, and the idea that Britain's coast is shrinking, is certainly relevant to the debate over nuclear power and the disposal of long-lasting nuclear waste, in my opinion. Take a look at the map of British nuclear power sites: they are all on the coast.

"It is a cause for concern, some nuclear power stations are in vulnerable positions," said Duck. He also highlighted the Easington gas terminal – one of the biggest in Europe – as being in a very vulnerable position.

It's always interesting, taking the long view.