UK flood damages will rise dramatically if climate change pledges not met

Researchers from the University of Bristol and water risk modelling firm Fathom used assessed future flood hazards, based on the most recent Met Office climate projections.

Its findings show the forecasted annual increase in national direct flood losses, defined as physical damage to property and businesses, due to climate change in the UK can be kept below 5 per cent above recent historical levels.

This scenario can only be achieved if all countries fulfil the climate pledges they signed up to at COP26 and that countries such the UK, which made further net-zero commitments, actually achieve these on time and in full.

If these are not collectively met, the annual cost of flooding in the UK over the next century could grow by between 13 and 23 per cent, depending on different levels of climate extreme projections.

Lead author Paul Bates, chairman of Fathom, said: “For the first time this flood model gives us a more accurate and detailed picture of the impact of climate change on the risk of flooding in the future across the UK.

“The results are a timely warning to the country’s political leaders and business sector that global commitments to significantly reduce carbon emissions must be taken very seriously, and ultimately take effect, in order to mitigate increased losses due to flooding.”

The data has also highlighted the places in the UK where risks will increase most rapidly, even under the best-case scenario where global warming is limited to 1.8°C. These include South East England, South Wales, North West England and Central Scotland, especially densely populated cities such as London, Cardiff, Manchester, Glasgow, and Edinburgh, where damage increases of more than 25 per cent are possible.

Conversely, the new model indicated flood hazards in North-East and Central England as well as Eastern and Northern Scotland would change very little from the present day.

“Although the most optimistic climate scenarios see only modest increases in flood losses at a national level, these new data demonstrate how this conceals dramatic variations across the country, with some places seeing large changes and others very little. This is a result of changing patterns of future rainfall, river flow and sea level rise, and this leads to the regional differences we predict,” said Professor Bates.

“We found that flooding increases most in places where risk is already high now, so the best thing we can do to prepare for the impact of climate change is to strengthen flood management in currently at-risk areas and this will bring immediate economic and social benefits as well.”

Previous studies have shown that historical UK economic losses due to flooding were three times less than the government’s estimates, but this is the first time the observed losses have been replicated and corroborated by a computer model.

Co-author Dr Oliver Wing, chief research officer at Fathom said: “The modelling provides clear evidence that flood risk needs to be a bigger international priority and that current governance doesn’t go far enough. While the majority of the nation’s future flood risk already exists today, it is strongly in the UK’s interest to exercise leadership in global carbon emission reduction efforts, both by example and as part of global diplomatic initiatives.”

Last month, a list of the world’s regions that are most vulnerable to climate change found that states and provinces in China and the US will be hit hardest, along with major cities and centres of economic activity around the world.