Homes, roads and fields around East Anglia's coastal region face being destroyed by rising sea levels, a report has warned.
The Committee on Climate Change (CCC) has warned that properties in England are at risk of damage from coastal flooding and erosion, with many communities unaware of the risks they face.
'Not fit for purpose'
The report warns that England's coast will see a sea level rise of at least one metre at some point in the future, with indications that this increase will happen over the next 80 years, within the lifetimes of today's children.
Around 370,000 homes in England are located in areas at risk of annual coastal flooding and erosion, with this number increasing up to 1.2 million by the 2080s.
In addition, approximately 1,600 km of major roads, 650 km of railway line, 92 railway stations and 55 historic landfill sites are at risk of coastal flooding or erosion by the end of the century.
Rising sea levels will make the most damaging coastal floods more frequent. However, the CCC said that many of England's coastal defences will struggle to cope and are vulnerable to failure as sea levels climb.
Professor Jim Hall, from the CCC Adaptation Committee, said: "The current approach to protecting the English coastline is not fit for purpose.
"It's time people woke up to the very real challenges ahead.
"As sea levels rise and flooding and erosion get worse, we have assessed that current plans for around 150 kilometres, or 90 miles, of the coastline are not cost-beneficial to implement.
"The Government and local authorities need to talk honestly with those affected about the difficult choices they face."
The regions affected by the rising sea levels include areas with soft, eroding shores in the south and east, as well as low-lying areas in East Anglia, Lincolnshire, parts of the south west, and the coast between Liverpool and Blackpool.
The coast of England is already covered by shoreline management plans, developed by the Environment Agency and local councils, but these would cost £18 billion to £30 billion to implement.
For 149 km to 185 km of England's coastline, the CCC say it will not be cost-beneficial to protect or adapt as currently planned by coastal authorities.
The CCC also criticised the government for failing to make the public aware of the flooding risks which threaten to destroy their homes.
The report states: "The public do not have clear and accurate information about the coastal erosion risk to which they are exposed, nor how it will change in future.
"There is no insurance or compensation for losses from coastal erosion for homeowners to mitigate the risk of losing their properties.
"Consequently, homeowners at risk may not take action to relocate or consider strategies beyond trying to protect their existing asset."
Professor Hall added: "Climate change is not going away: action is needed now to improve the way England's coasts are managed today and in the future, to reduce the polluting emissions which cause climate change, and to prepare seaside communities for the realities of a warming world."