Huge swathes of the Broads, the Fens and even parts of Great Yarmouth and Norwich could be under water in 30 years unless drastic action is taken to halt global warming.

That is the shocking conclusion drawn from a new interactive flood-risk map built by US-based researchers who claim that global vulnerability to sea level rise is worse than previously understood.

MORE: New bar set for Panda site despite rates rowThe data is based on CoastalDEM, a new digital model for coastal elevation developed by Climate Central. Even in a scenario in which "moderate" reductions are made to the amount of human-made pollution, it shows that by 2050 rising sea levels could push chronic floods higher than land currently home to 300 million people worldwide, with Asia being the worst affected.

Closer to home, the map shows East Anglia's low-lying Fens, to the west and south of The Wash at King's Lynn, among the worst-hit areas in the UK, with other red zones along the north Norfolk coast and along the Yare and Waveney river valleys in the Broads.

MORE: Photos show Norfolk's disappearing coast

Areas shaded red on the map are those predicted to be below annual flood level in 2050 - although protective defences such as seawalls and levees are not included in this analysis as the report says global data on these features is not publicly available.

"These assessments show the potential of climate change to reshape cities, economies, coastlines, and entire global regions within our lifetimes," said Dr Scott Kulp, a senior scientist at Climate Central and lead author of the study.

"As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much, and how long coastal defences can protect them."

But despite this sobering scenario, the report says there is still a chance influence the severity of the change. With global sea levels projected to rise between about 2ft and 7ft by the end of this century, it says one of the key variables dictating whether that figure will be at the higher or lower end of the range will be "how much warming pollution humanity dumps into the atmosphere".

Climate Central's findings were documented in the scientific journal Nature Communications.