The north and west will experience record rainfall, with longer heatwaves and droughts in the south and east.
The report by the Environment Protection Agency found:
* Average temperatures will rise by 1.4C-1.8C by 2050.
* By the same year winters will be about 10% wetter while summers will have between 12%-17% less rain.
* Summer reductions of rainfall between 20%-28% are projected for the southern and eastern coasts, increasing to 30%-40% by the 2080s.
* There will be a substantial drop in the number of frost days.
Soils will begin to dry out and catchment areas more dependent on groundwater — such as the Blackwater, Suir and Barrow rivers — appear most vulnerable to the shifting rainfall patterns.
Most worrying is the pace with which floods begin to hit the country. The EPA said 10-year floods could become three to seven-year events on most catchments by the 2050s, and the 50-year flood becomes a six to 35-year event almost everywhere.
The report, Climate Changes in Ireland: Refining the Impacts for Ireland, predicts that summer rainfall in the south and east will fall by up to 28% by 2050 and by up to 40% by 2080.
However, there are also likely to be higher rainfall levels during the winter months, increasing the risk of flooding in many areas, especially the midlands. “We are looking at changing extremes at both ends of the spectrum — more rain and more intense rainfall at one end and then heatwaves and drought at the other,” said report’s lead author Prof John Sweeney.
Climate changes would pose challenges for agriculture due to wetter winters and drier summers with many farmers likely to switch to different crops, he claimed.