The study, published today in the peer-reviewed journal Oceans and Coastal Management, says that sea levels around the country will be around 35cm higher within almost three decades than their historical level as global temperatures increase.
It describes how investment in sea walls and other defences will protect many of the properties at risk, but this may not be affordable or possible elsewhere.
Researchers have calculated how many English properties will be threatened with coastal flooding but where the costs of improving defences may be too high or technically impossible for the government to continue to protect communities given current funding regimes.
By the 2050s, 120,000-160,000 properties along the English coast would be at risk of relocation due to sea level rise, in addition to 30-35,000 properties that had already been identified as at risk from sea level rise.
The report lists 20 local authorities that have 2,000 or more, some with tens of thousands, properties at risk of being lost to sea level rise with Eastbourne ranked third behind North Somerset and Sedgemoor.
Lead author Paul Sayers said: “Significant sea level rise is now inevitable. For many of our larger cities at the coast protection will continue to be provided, but for some coastal communities this may not be possible. We need a serious national debate about the scale of the threat to these communities and what represents a fair and sustainable response, including how to help people to relocate.”
The project will become one of the largest coastal flood risk schemes in the country and help make Eastbourne to Pevensey Bay more resilient to coastal flooding.
When completed, the new sea defences will increase protection to an estimated 10,000 homes, key infrastructure, local businesses, heritage sites and nature conservation areas.
Meanwhile last week the EA launched a national roadmap setting out practical actions to be taken over the next four years to tackle the growing threat of flooding from rivers, the sea, and surface water as well as coastal erosion.