Temperatures exceeding 30 degrees likely to become more common in Ireland – study

Ireland will experience more frequent extreme heat, impacting over larger areas of the country with temperatures exceeding 30 degrees, climate scientists at Maynooth University (MU) have said.

They have developed much more accurate prediction models on the extent of Irish heatwaves, which will be more challenging than relatively isolated temperature spikes in the past. They indicate heatwaves have doubled in area in more recent times.

Their findings based on weather station data indicate the urgent need for “societal adaptation to increasing extreme temperature events, that will have profound implications for public health, agriculture, economic stability and infrastructure resilience,” said lead researcher Prof Andrew Parnell.

They estimate that a temperature of more than 34 degrees – a value not yet recorded in Ireland – changed from a 1 in 1,600-year event to a 1 in 28-year event between 1942 and 2020.

A “temperature event” of 33 degrees in Dublin’s Phoenix Park has gone from being a once in 180-years event in 1942 to a once in nine-years event in 2020, they forecast.

The new model to predict the frequency, magnitude and spatial extent of extreme summer temperature events in Ireland, was carried out by a team including Dr Dáire Healy, in collaboration with Prof Peter Thorne of MU’s ICARUS Climate Research Centre and Prof Jonathan Tawn of Lancaster University.

[ Europe warming at twice rate of other continents as heat stress severely impacts public health – climate report ]

Prof Parnell said: “We are often focused on average changes, and particularly focus on the Paris Climate Agreement of 1.5 degrees. What we have shown here is that the changes in extremes are much larger than the changes in the average, and are something we should be seriously concerned about.”

Compared to the 1940s and 1950s extreme heat events will be more frequent, involve higher temperatures and be more widespread due to human-caused global warming, he said. They will be less isolated rather than occurring, for instance, at a weather station in the Phoenix Park.

The highest temperature ever recorded in Ireland was 33.3 degrees at Kilkenny Castle on June 26th, 1887.

“We found that spatial heatwave events over thresholds that are critical for society have become much larger, having at least doubled in extent for 28 degrees, with this change increasing at more extreme temperatures,” Dr Healy said.

The technology and mathematics deployed involves processing of more data, which is enabling the generation of smarter maps that help identify patterns when such extreme weather events occur – and can be used as a weather forecasting tool that will be particularly beneficial for health services and farmers, Prof Parnell said.

The research team believe the model’s ability to predict spatial patterns of extreme events also offers a powerful tool for policymakers and stakeholders to mitigate risks and plan for future climate scenarios.

He hoped the next stage of the research would look at implications for emergency services, and examine likely crop impacts such as effects on oats, in terms of growth and disease threat.

Their findings were outlined The Royal Statistical Society at a meeting on statistical aspects of climate change recently.