Minsmere, at the edge of the sea in Suffolk, is so threatened by the consequences of global warming that RSPB staff are starting to think what would once have seemed the unthinkable: to recreate it further inland.
Its reedbeds, marshes, lagoons and islands, teeming with bird life but protected from the waves only by a rapidly-eroding shingle bank, are increasingly at risk from invasion by the sea, because of the sea-level rise and growing storminess that climate change is bringing. And the RSPB is coming to accept that it may not be possible to defend the whole reserve.
Shifting Minsmere, in whole or in part, would be the most eye-catching example yet of the controversial policy the Government is espousing to cope with the effects of rising seas on some of Britain's coastline: managed realignment. This was originally referred to as "managed retreat", but that term was thought by some to have a defeatist ring.
It means ceasing to maintain sea defences in some cases, where, for example, the cost might be thought hugely disproportionate to the benefits, and letting the sea flood in, so creating a new coastline behind the original one.
The policy has been adopted by the Department for Environment, Food and Rural Affairs, is being implemented by the Environment Agency, and is backed by environmental bodies such as English Nature, the Government's wildlife adviser, because it is perceived as ecologically more natural and beneficial than building gigantic concrete sea walls to oppose an inevitable natural process. But it is opposed by farmers' groups such as the National Farmers' Union and the Country Landowners' Association. They are concerned that while coastal towns will nearly always be thought worth protecting, farmers' fields and isolated houses may not. And if the Government decrees that a swath of coastal farmland or a cottage is too expensive to save from the rising sea, there are no plans to compensate the owner or provide an appeal process against the decision.
A vociferous opponent of managed retreat - as he insists on calling it - is John Gummer, the former Conservative environment secretary who is the MP for Suffolk Coastal, a constituency with 74 miles of vulnerable shoreline. Mr Gummer has started a group called Scar - Suffolk Coast Against Retreat - "to fight the Government's proposals for `managed retreat' which actually means flooding our homes and land!"
The RSPB is taking an urgent look at the issue, as several of its most popular reserves are on or close to the east coast, the area of the British Isles that sea- level rise is likely to hit hardest.
The land in the south-east quarter of England is sinking, as well as suffering from a rising sea. The society has been given a working estimate from the UK Climate Impacts Programme that the combined effect will be to push sea levels in East Anglia up by between 21 and 76 centimetres by 2050, enough to overwhelm many sea defences.
Minsmere, halfway between Southwold and Aldeburgh, is its greatest concern because it is the RSPB national flagship reserve. It was where avocets, black and white wading birds which had been extinct in Britain for 100 years, returned to breed in 1947. Because of its unique patchwork of habitats, ranging from beach and marsh to pine forest and lowland heath, Minsmere hosts more than 100 breeding species of birds, many of them rare.
But a solution cannot be specified until the coastal processes - the erosion and deposition of material on the beaches - are better understood. The Environment Agency is carrying out a study and when it reports later this year, the options for defending the reserve will become clearer.
"Even though we want to see the reserve protected, in the longer term we will have to accept that changes are going to take place," said Helen Deavins, RSPB conservation officer for the area. "We have to start looking at where we can recreate the habitats. It won't be for a while yet. But it's on the cards."Reuse content