Rising sea levels could transform Britain into islands

Sea level rise caused by climate change could eventually turn Britain into a string of disparate islands, a study published today suggests.

Even considerably smaller rises could drown the centre of London and leave many low-lying cities and coastal towns waterlogged, including Edinburgh, Newcastle, Scunthorpe, Bristol, Plymouth, Norwich, Peterborough and Bournemouth - with well over two million people displaced, according to the Benfield Hazard Research Centre at University College, London.

Global sea levels are expected to rise with rising temperatures, from the melting of ice sheets at present sitting on land, and the expansion of sea water in volume as it warms. (Melting sea ice will not raise levels as it is already displacing its own mass - a melting ice cube does not raise the level of your gin and tonic.)

Now a team from Benfield has looked into just how vulnerable Britain is to the encroaching waves by matching rising sea level scenarios against ultra-accurate data on the UK's topography gathered by the US Space Shuttle.

The result, say the team, is the first-ever detailed maps showing the possible impact of global warming on the shape of the British landscape.

The study, commissioned by the cable and satellite channel UKTV History, was led by Benfield's Director Professor Bill McGuire, the UK's leading authority on natural catastrophes, and focused on three potential scenarios for the future:

1. A 7m rise in sea levels if either the Greenland or the West Antarctic Ice Sheet melted.

2. A 13m rise, if both the Greenland and West Antarctic Ice Sheet melted.

3. A remarkable 84m rise if the East Antarctic Ice Sheet also melted. Some experts believe there could be at least a one in 20 chance that the West Antarctic Ice Sheet could melt some time in the next 200 years.

This scenario would lead to a rise of 6-7m in sea levels that would drown the centre of London, while in the surrounding area, much of the boroughs of Southwark, Lewisham, Greenwich, Tower Hamlets, Bexley and Barking & Dagenham would be under water, the study shows.

Large areas of south Essex and north Kent earmarked for the Thames Gateway Development would also be submerged, as would many coastal towns and cities from Edinburgh to Bournemouth.

A 13m rise would see the sea encroaching far inland, especially in East Anglia, Lincolnshire, East Yorkshire, Cheshire and the Severn Estuary.

The 'Doomsday' scenario is an 84m rise, although this is extremely unlikely and will only happen if we do nothing about carbon gas emissions, leading to a runaway greenhouse effect.

Were we ever to reach this state, little beyond the hills and mountains making up Wales, Scotland, the South West and the spine of England will remain above the waves, as an island archipelago where Britain once was.

"It is clearly the West Antarctic Ice Sheet that is most worrying," Professor McGuire commented.

"If this melts, along with the continued thermal expansion of sea-water, we could see London and many other coastal cities disappearing beneath the waves in the next 200 years."

The study was commissioned by UKTV History to celebrate its forthcoming series 'The British Isles - A Natural History' which runs throughout this week.

"Seeing how natural history has shaped the land we live in today is fascinating, but we also need to look to the future,: said Adrian Wills, UKTV History's editor.

"Our research shows that we can't afford to take Britain for granted, since even a small change in sea levels could have a devastating effect on the UK."

- INDEPENDENT