Which Irish cities will be hardest hit by flooding in the future?

Europe-wide study shows worsening heat waves, droughts and flooding for all cities

Dublin city councillors have voted to spend €500,000 to lower and reface part of the recently built flood defence sea wall in Clontarf. The council warned if the wall was not lowered motorists would have restricted views of the sea.

 

All European cities are set to be hit harder by future extreme weather events than previously thought, with Cork, Dublin, Waterford and Derry among those to be worst affected by flooding, according to new research.

A study carried out at Newcastle University, published in the journal Environmental Research Letters, analysed changes in flooding, droughts and heat waves for all European cities for the first time using climate models.

The researchers showed results for three possible futures which they called the low-, medium- and high-impact scenarios. It compares the period 1951–2000 with projections for 2051–2100.

The study shows a worsening of heat waves for all 571 cities; increasing drought conditions; and an increase in river flooding.

Ireland and the UK have some of the worst overall flood projections. Even in the most optimistic scenario, 85 per cent of UK cities with a river – including London – are predicted to face increased river flooding.

The Irish and UK cities predicted to be worst hit under the high-impact scenario are Cork, Derry, Waterford, Wrexham, Carlisle and Glasgow and for the more optimistic low-impact scenario are Derry, Chester, Carlisle, Aberdeen, Glasgow and Newcastle.

Of the European capitals, Dublin, Helsinki, Riga, Vilnius and Zagreb are likely to experience the most extreme rise in flooding.

For the high-impact scenario, several European cities could see more than 80 per cent increases on peak river flows, including Cork, Waterford, Derry, Santiago de Compostela in Spain, Braga and Barcelos in Portugal.

Maximum temperature

In terms of the other weather events, the study shows that even in the low-impact scenario both the number of heat wave days and their maximum temperature will increase for all European cities.

Southern European cities will see the biggest increases in the number of heat wave days, while central European cities will see the greatest increase in temperature during heat waves – between 2-7 degrees for the low scenario and 8-14 degrees for the high scenario.

For the low-impact scenario, drought conditions only intensify in southern European cities, while river flooding only worsens in northwestern ones.

By 2051-2100 for the low-impact scenario cities in the south of Iberia, such as Malaga and Almeria, are expected to experience droughts more than twice as bad as in 1951-2000.

In the high-impact scenario, 98 per cent of European cities could see worse droughts in the future, and cities in southern Europe may experience droughts up to 14 times worse than today.

Stockholm and Rome could see the greatest increase in number of heat wave days, while Prague and Vienna could see the greatest increase in maximum temperatures during heat waves.

Breaking point

Dr Selma Guerreiro, lead author of the research, said the increase in droughts could push cities “beyond breaking point”.

“Although southern European regions are adapted to cope with droughts, this level of change could be beyond breaking point.

“Furthermore, most cities have considerable changes in more than one hazard, which highlights the substantial challenge cities face in managing climate risks.”

Prof Richard Dawson, a co-author, said the research highlighted the “urgent need” to design and adapt cities to cope with future conditions.