Climate change: Water will be the issue for Ireland

Data is pointing to a much stormier future, plus extreme rainfall events

Lough Derg: “The big thing for Ireland is rainfall and storms, with rainfall either too much or too little,” says Dr Conor Murphy of Maynooth University

Lough Derg: “The big thing for Ireland is rainfall and storms, with rainfall either too much or too little,” says Dr Conor Murphy of Maynooth University

 

For Ireland, the future of climate change is going to be all about water – having too much of it or too little, getting swamped by it or roasting in its absence.

“We have got problems coming down the line,” warns Dr Frank McGovern, chief climate scientist at the Environmental Protection Agency. “Ireland is not an easy place to predict our future climate conditions.”

There are decades of data to point the way towards what our climate future might be however, and water will be the issue.

“Rainfall data is telling us there will be an average decrease in rainfall but an increase in extreme rainfall events,” says Dr Barry O’Dwyer, who is based in University College Cork’s centre for marine and renewable energy.

“The coastal observational evidence is that we can expect a half metre rise in sea levels around our coasts. I think we have to look at flooding issues now. We have to be able to increase our ability to cope and how the situation will change in the future,” he says.

“The big thing for Ireland is rainfall and storms, with rainfall either too much or too little,” says Dr Conor Murphy of Maynooth University’s Irish Climate Analysis and Research Units (Icarus). “Our understanding from the data shows wetter winters. It is a very strong trend and it shows that the intensity of rainfall has been increasing.”

The researchers believe there is plenty of data to show we will also have a much stormier future. “We have seen the trends and they agree with the models,” Dr Murphy says. “All we have to do is look at the extremes – for example, the flooding from last year. It could be anything from 10 per cent to 40 per cent wetter in winter.”

Flooding

Storms in turn mean flooding from two sources, one upriver – too much water trying to reach the sea – and one downriver, rising sea level delivering higher storm surges that push water back upriver. Most of our cities are on the coast, meaning we will also become even more vulnerable to coastal erosion as sea levels rise.

The EPA commissioned a major climate modelling exercise that would help predict what our weather future holds. It was carried out by Dr Paul Nolan, who was previously based at University College Dublin and is now working at the Irish Centre for High-End Computing and Met Éireann. *

The exercise comprised repeated modelling runs to create an ensemble of projections.

Dr Nolan’s study found that temperatures here would rise by between 1 and 1.6 degrees by 2050 , with higher temperatures in the east. Average night-time temperatures would rise and the number of frosty days would be cut in half. This in turn would lengthen the growing season by more than 35 days a year, he found.

There would be “significant decreases” of up to 13 per cent in average rainfall amounts over most of the year or up to 20 per cent assuming less action on controlling climate change.

But there would be a 20 per cent increase in those driving, near tropical-type rainfall events that are becoming more familiar to us. Summer in particular will be populated by short-run droughts lasting at least five days, Dr Nolan’s study found.

Unfortunately for the wind-energy industry, projections show significant decreases in the energy content of wind for most of the year except winter. This will range from 3 to 10 per cent in a low emissions environment or 7 to 15 per cent in a high emissions regime.

“The trouble with CO2 with is once there it stays for centuries and that is part of the difficulty we have,” says Dr McGovern.

He does not despair, however. “We still have time to put the brakes on. I am not going to say there are no solutions.”

He says we have to get to zero carbon emissions as soon as possible. “We need to invest in research to find solutions,” he adds.

* This article was amended on November 2nd, 2016