The climate crisis has a particular significance for East Anglia. From the Thames estuary to the Humber, the land has been slowly sinking for millennia. Scientists predict that it will sink by 5 centimetres this century, while sea levels rise.
Coastal erosion: sinking land and rising sea
Over the centuries, whole villages, like Shipden (off Cromer) have vanished under the North Sea. Dunwich, in Suffolk, once the capital of the Danish kingdom of East Anglia, has largely disappeared. At the same time, shifting currents and tides have sealed off ports like Brancaster, once a major hub trading with Northern Europe and the Baltic.
Climate crisis adds to this. Sea levels are predicted to rise by up to a metre by the end of the century. On this basis, without major sea defences, the sea could reach to the outskirts of Cambridge and Peterborough; flood much of East Norfolk; and drown large areas of coastal land in Suffolk and Essex. But stronger coastal defences could push flooding into the Thames estuary, over the Thames Barrier and into London.
A further effect of climate change is increasingly heavy rainfall which overloads rivers, which then flood. Where inland floodwaters meet tidal surges in low lying areas, as in Norfolk, the potential for severe flooding is considerable.
Erosion
Much of the coast of the region, especially in Norfolk and north Suffolk, consists of soft cliffs. These are very vulnerable to erosion by the sea. Over time, the rate is modest, at a metre or two a year. But in some places, like Covehithe, just north of Southwold, land is disappearing at a rate of 4.5 metres a year, and estimates are that the village will disappear entirely by the end of the century.
This is made much worse by storm surges, which can cause major collapse overnight. The worst surge on record was in 1953, when an exceptional tide combined with hurricane force winds. The resulting 3 metre tidal surge killed 307 people, mainly in low lying parts of Essex. In Happisburgh in North Norfolk, buildings go over the cliff every few years. In Spring 2021, half a recently renovated path to the beach vanished overnight, and a canyon some 25 metres long opened up in a field.
However, while erosion is destroying farmland and in some cases housing, it also plays a positive role. The sand released to the beaches of North Norfolk is carried south by tides and currents. Without this replenishing of their beaches, Great Yarmouth and Lowestoft would themselves be at risk. Measures which stop this flow of sand may make erosion worse by simply sweeping sand out to sea.
Protecting the coast
A variety of measures have been used to reduce the risk of erosion. Historically, groynes have been used to prevent sand being washed away down the coast, and solid sea walls built to protect cliffs and houses. More recently, artificial reefs have been constructed. All have some impact, but they also have unpredictable results elsewhere by changing the flow of currents and tides. When a major tidal surge comes down the North Sea, better defences in Norfolk may create greater problems in Suffolk, and better defences in East Anglia could threaten the Thames estuary and London.
Critical infrastructure
Much of the region’s coast is thinly populated, and towns and villages are either well inland or, like Hunstanton, Cromer and Southwold, are built on rocky outcrops that are relatively protected from erosion. However, there are two major infrastructure sites at serious risk from the sea.
The first is the Bacton gas terminal on the Norfolk coast. A third of the UK’s gas supply comes ashore here from the North Sea. In one storm in 2013, ten metres of land was lost there, leaving only fifteen metres between the sea and the terminal. As a result, £22 million was spent on laying 1.8 million cubic metres of sand on the beach. This will hold back the sea for some years, but eventually the sea will carry it away and the process will have to be repeated.
The second is at Sizewell. The planned Sizewell C nuclear power station in Suffolk, will also stand on the coast, beside its predecessors (Sizewell A, now being decommissioned, and Sizewell B, due to close in 2055). Sizewell C has a predicted life from construction to decommissioning, of 150 years. A lot could change during that time. It will stand on a rocky outcrop, and EDF, the constructors, have plans for sea defences. However, environmental campaigners have expressed concern about the risk of flooding of coastal nuclear plants (like Fukushima in Japan and the Dungeness in Kent, both of which are now closed down).
Planning for a changing future
Stopping erosion is not realistic or even desirable. The Environment Agency’s assessment is that “climate change increases the risks and means we need to build on our progress, but we can’t do so infinitely. It is not realistic to try to manage more, increasingly intense, flooding and sea level rise with limitlessly high walls and barriers.”
As a result, 100-year Shoreline Management Plans have been prepared jointly by the Environment Agency and Local Authorities for the whole UK coastline. These examine the coast in great detail, listing each area in one of four categories: protection, reclamation, managed realignment or unmanaged change. Coastal erosion will be allowed to continue in Norfolk to replenish the protection provided by beaches further south. The plans also highlight the need to produce social plans to prepare and compensate people whose homes and property may be at risk in the medium or long term.
The government has spent £2.6 billion on flood and coastal erosion to protect some 300,000 homes. But much of the money is being spent on inland river flooding. The Environment Agency estimates that 700 homes are vulnerable to coastal erosion by 2030.
Living with change
Even if the world succeeds in slowing or stopping global heating in the long term, nothing can now stop sea levels rising and rainfall increasing in our lifetimes. Whatever measures are taken, the risks of increased flooding and erosion are going to rise in East Anglia. There is no doubt that the impact in the next decades will be greater than in the past.
The unknown question is, how much greater?
