Living on the edge

Britain's coastline has remained more or less intact since the end of the last ice age. But as sea levels rise, erosion is accelerating and more than a million homes are now under threat. Is the only solution for us to abandon the shore?

Adam Nicolson reports
Monday October 9, 2006The Guardian

If you had been alive 18,000 years ago, you could have walked in a straight line from Cork to Stockholm. The floor of the North Sea was land. Objects have been found from that strange, drowned world. A carefully sharpened flint scraper has been retrieved by Norwegians drilling for oil in 450 feet of water 100 miles east of Shetland. Spearheads and mammal and rhinoceros teeth have been dragged up by trawlermen on the Dogger Bank. Sometimes in their trawls fishermen find lumps of peat from forgotten moors. It is an unsettling fact that tens of thousands of people once knew the floor of the North Sea as well as any of us might know the Yorkshire Dales or the Sussex Downs.

When this periglacial world began to warm up about 20,000 years ago, the ice sheets melted and sea-level rose, on average, at about a centimetre a year. By 5,000BC it was some 130m (430ft) higher than it had been at glacial maximum and Britain had become an island. But then the warming slowed. Since 2,000BC the sea level has remained extraordinarily constant, varying no more than a metre in 4,000 years. This period of sea-level stability has also seen the rise of urban and commercial civilisation. We have built our cities on a constant shore. That long constancy has allowed us to forget that we have been living in a privileged world. But that privilege is now over. The physical conditions of the world are changing for the first time since humanity started to build. For thousands of years we have shaped the world. Now, for the first time, the world is going to shape us.

It is the most subtle and unknowable of processes. The rocks of this country are, in part, still bobbing up in response to that huge ice load having been removed. An enormous boss of Scotland and northern England, stretching from Inverness to Morecambe Bay and from Edinburgh to Islay, is actually rising in relationship to the sea. But outside that protuberant bump, the country is slowly going under, largely because, as the earth warms up, the water in the oceans is expanding. Dire predictions of a sea-level rise of 6m or even 10m have been made regularly over the years, but the evidence is contradictory. Such a vast increase will depend on the total melting of the Greenland and West Antarctic ice sheets, but it may be that a warmer atmosphere, which can hold more moisture, will actually increase snowfall over Antarctica, thickening the ice sheet and so reducing, or at least stabilising, global sea levels. The science remains tentative. >>>cont

LinkHere