Climate change is widening the east-west divide in Ireland's weather patterns, according to a new study – with one side of the island likely to experience future droughts and the other set to become even wetter.
A report for the Environmental Protection Agency (EPA), Met Éireann and the Marine Institute, written by Walther Cámaro García and Ned Dwyer of UCC’s MaREI energy, climate and marine research centre, shows that as the planet heats, an overall increase in rainfall is affecting parts of Ireland in different ways.
There has been a 6 per cent rise in precipitation over the past 30 years when compared to the previous three decades, the study says.
But data gathered from 35 stations measuring the flow of Irish waterways show that while rivers in the west and north are getting heavier – bringing with it the increased threat of flooding – rivers in the south and the east in particular are at risk of trickling out.
The Status of Ireland’s Climate report, the first comprehensive study of its kind in eight years, says there is “evidence in recent years of an increase in potential drought conditions especially in the east”.
Overall river flow trends in the study relate to records from between 1972 and 2017. But more recent data, for a more limited time period, suggest a widening east-west split in how climate change is affecting Ireland’s rivers.
EPA chief scientist Frank McGovern described it as an “emerging signal”.
“There is a variation in rainfall patterns in Ireland and we have an east-west divide,” he told The Irish Times.
“It rains more in the west, and certainly the northwest, than it does in the east, so obviously that has its impacts. One assumption is the east will get drier, the west will get wetter.”
Ms McGovern said that given a majority of the population lives in the east, where there is a significantly higher demand for water supplies, the findings “should inform investment in planning and making our infrastructure and population more resilient to climate change”.
Extreme events
The report shows increased rainfall in Ireland is “more or less in line” with trends elsewhere in the northern hemisphere. The trends point to “more intense, almost tropical rainfall events” in the coming years and decades, which can be “extremely heavy and short”, he said.
Referring to the recent flooding in Germany – the worst in decades, which killed more than 180 people and is expected to cost billions to recover from – Mr McGovern said it “was as an example as to what can happen. It is much harder to manage these rainfall events.”
The report, following on from a 2012 study, shows the “trends are continuing” and that scientists in Ireland are now “more certain” that the country is getting warmer and wetter.
“This effectively shows climate change is happening here and eco systems are responding,” said Mr McGovern. “We have to take on board the risks that arise from that and try to manage those risks... It is challenging to respond to, because we are dealing with a widening oscillation of extremes.”
He added that longer-term risks included sea level rises and coastal erosion, and that forward planning would be needed to “ensure our coastal communities and cities are resilient or able to manage that”.