The cost of a 200-year flood event could escalate by 42% to £5 billion by the middle of the century under an intermediate emissions scenario (RCP4.5). And, if there is no action to reduce emissions, the UK could see a hike of up to 87% in average annual losses to residential properties.

There could also be a 120% increase in the cost of surface water floods, particularly in the south and east of the UK under a no-action RCP8.5 scenario.

The stark findings follow the launch of JBA Risk Management’s latest version of its highly customisable UK Flood Model, which now includes two new climate scenarios representing intermediate and unmitigated warming by 2050 and thousands of new future events, including events of increased severity and spatial coverage.

Judith Ellison, Climate Change Commercial lead at JBA Risk Management commented, said: ”Our latest UK Flood Model has been developed using new methodology and the latest UK Climate Projections from the Met Office while building on practical learnings and client feedback from our 10 years of flood modelling experience.

”The key element of the latest approach is the ability to build new and more severe events – with thousands of new events in total– to more effectively reflect the potential impacts from climate change and give users greater insight into the challenges of future risk.”

The model also shows that whilst river flooding remains the dominant risk from climate change, particularly in the west of the UK, the greatest change in flood losses comes from coastal flooding – with a 150% increase under a no-action RCP8.5 scenario by 2050.