Temperatures, droughts and heavy rain events all set to increase – report

Irish weather is forecast to see much more extreme weather conditions over the coming decades as temperatures rise, according to a new report.

Climate scientists at the Irish Centre for High-End Computing (ICHEC) have completed sophisticated high-resolution Regional Climate Model (RCM) simulations for Ireland which predict that by the middle of this century (2041–2060) Ireland will see dramatic changes in climate.

Deemed to be the first systematic study of this kind at this scale, the research was carried out on behalf of the Environmental Protection Agency (EPA) and supported by Met Éireann and the Marine Institute.

It presents projections of climate fields and derived variables that are of importance to sectors including agriculture, health, energy, flooding, water management, biodiversity and transport.

Selected findings from this study indicate that by mid-century (2041–2060):
  • Temperatures are projected to increase by 1–1.6° compared with the baseline period (1981–2000), with the largest increases in the east;
  • Warming will be enhanced at the extremes (hot days and cold nights), with summer daytime and winter night-time temperatures projected to increase by 1–2.4°;
  • Substantial decreases of approximately 50% are projected in the number of frost and ice days;
  • Summer heatwave events are expected to occur more frequently, with the largest increases in the south;
  • The precipitation climate is expected to become more variable, with substantial projected increases in the occurrence of both dry periods and heavy precipitation events;
  • The length of the growing season is projected to increase by between 12% and 16%;
  • Substantial changes in 10m wind speeds, storm tracks, mean sea level pressure, growing/grazing season, “growing degree days”, surface evapotranspiration, humidity, heating/cooling demand and solar energy resources are also projected by mid-century.

ICHEC climate scientist and project lead, Dr. Paul Nolan, ran an ensemble of RCMs on the national supercomputer ‘Kay’ to generate high-resolution climate projection data which allowed for a more detailed assessment of the potential regional and local effects of climate change.

“The models show that the effects of climate change will not be evenly spread across Ireland; the east, for example, will see higher overall temperature increases than the west,” Dr. Nolan said.

“Furthermore, the fine detail of the models results in a more accurate representation of the climate, and in particular, extreme events such as heavy rainfall, droughts and heatwaves,” he added.

Image source: ICHEC
Image source: ICHEC

The research presents projections of additional climate fields and derived variables that are of importance to sectors including agriculture, health, energy, biodiversity and transport.

Commenting on the significance of the report, Alastair McKinstry, environmental programme manager, ICHEC, said:

Ireland’s climate is changing; our models indicate this is resulting in higher temperatures, changing precipitation patterns and increases in the frequency and intensity of extreme weather events, with these changes expected to continue and intensify into the future.

“The local climate projections, presented in this report, can assist national policymakers to plan for, and adapt to, the adverse effects of climate change at regional level.”