United Kingdom: Climate change risk assessment 2017 - Projections of future flood risk

This report presents the analysis for future flood risks in the United Kingdom in support of the climate change risk assessment (CCRA) published every five years by the government. 

The assessment of future flood risk presented considers three climate change scenarios (a 2oC and 4 oC change in Global Mean Temperature by the 2080s and a H++ scenario) and, three population growth projections (low, high and no growth). For the first time the analysis presented covers the whole of the UK (England, Wales, Scotland and Northern Ireland) and the risks associated with coastal, fluvial, surface water and groundwater flooding.

Eight individual Adaptation Measures (including, for example, spatial planning, flood defences, catchment storage) are used to construct five Adaptation Scenarios (including enhanced and reduced levels of adaptation ambition in comparison to present day). Future flood risks for a range of climate, population and adaptation combinations are assessed using the UK Future Flood Explorer and the results presented. 

The report concludes that:

• Significant additional investment and adaptation action will be needed to counter the increase in UK flood risk projected under a 2°C rise in global mean temperatures.
• Even the most ambitious adaptation scenarios will not be able to avoid the large increase in UK flood risk implied by a 4°C rise in global temperatures.
• Long stretches of current coastal flood defence structures in England will become highly vulnerable to failure as sea levels rise, making it increasingly more difficult and costly to manage the risk of widespread coastal inundation.