Guidance warns Ireland to prepare for rise in 'extreme weather events' in the future

Sandbags piled up in Bantry which flooded after Storm Barra in December 2021. The climate guidance sent to meteorologists in Met Éireann said: “Irish rainfall patterns are expected to change, with an increase in both dry periods and heavy rainfall events.” File photo: Andy Gibson/PA

Advice given to forecasters in Met Éireann said Ireland needed to prepare itself for much heavier rainfall, storm surges and coastal flooding, as well as the growing “likelihood of extreme weather events”.

The climate guidance was sent to meteorologists in June amidst a summer of freak weather events globally including record-breaking temperatures, catastrophic flooding, and out-of-control forest fires.

The Met Éireann guidance said it was “beyond doubt” that human influence had warmed the atmosphere, ocean, and land, and that temperatures here were up by approximately one degree Celsius since 1900.

It said this made extreme weather events more likely but that it was difficult to say how this would impact the frequency and intensity of storms in Ireland, with further research needed.

The advisory said our climate had become significantly wetter, with annual rainfall in the 1991 to 2020 period 7% higher than what was experienced between 1961 and 1990.

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The document said: “Irish rainfall patterns are expected to change, with an increase in both dry periods and heavy rainfall events.” It said there was “high confidence” that we could expect maximum rainfall rates to increase as the warmer atmosphere would carry more moisture.

The guidance added that a warmer atmosphere could be expected to carry 7% more moisture for every degree of warming with heavy rainfall events inevitably increasing in intensity.

It added: “Global sea level continues to rise. As a result, storm surge and coastal flooding risk around Irish coasts is expected to increase.” 

On the heatwaves that have hit many different areas, the Met Éireann advisory said these were becoming more frequent and more intense, driven mainly by “human-caused climate change”.

It said some of the most extreme heat events seen in recent years would have been very unlikely in the absence of human influence, including the so-called “heat dome” that developed in the Pacific Northwest during 2021.

The Met guidance said with changing rainfall patterns in Ireland, there would likely be an increase in both extended dry periods and heavy rainfall events.

Flood water on Pembroke Street in Cork city after an early morning high tide in December 2021. The advice to meteorologists said Ireland's mean sea levels were broadly in line with global trends but that worryingly, higher rates had recently been observed in both Cork and Dublin.

“More severe agricultural and ecological droughts are projected under climate change; the more the planet warms, the more severe and widespread the drought impacts will be,” it said.

On Irish sea surface temperature (SST), it said changes there had been more unpredictable with periods of warming and cooling but that marine buoy observation appeared to show climbing rates again.

The advisory said global sea levels had increased by approximately 0.2 metres over the past 118 years and that the pace of this was “accelerating”. It said in Ireland mean sea levels were broadly in line with global trends but that worryingly, higher rates had recently been observed in both Cork and Dublin.

The Met document said it was “unclear why” this was so and that it was “currently under investigation”.

The advisory said “key messages” based off recent data should be that 2022 was the warmest on record in Ireland, the twelfth consecutive year with above normal temperatures in the country.

The all-time highest maximum temperatures for July and August had both been broken at the Phoenix Park at 33 degrees, and in Oak Park, Carlow at 31.7 degrees. Asked about the records, Met Éireann said they did not plan to issue a statement at this time.