In 2008, the Environmental Protection Agency published a study titled “Climate Change – Refining The Impacts For Ireland” by Professor John Sweeney et al. This study concluded that relative to 1961-1990 average Irish precipitation, “winter rainfall in Ireland by the 2050s is projected to increase by approximately 10% while reductions in summer of 12–17% are projected by the same time”. In a more short-term rainfall prediction, the study also stated that “winter precipitation is likely to increase marginally by the 2020s, by approximately 3%, with summer reductions of a similar order of approximately 3%.”
There was significant political weight attached to this study at the time. For example, The Irish Times reported on the forecasts in the study by stating that “Ireland needs to get ready for periods of droughts” during future summers. The then Green Party Minister for the Environment John Gormley, reacted to the report by stating that, “the consequences of climate change are occurring much faster than previously suggested and are worse than first thought. This means that we will have to live with and adapt to substantial climate change … particularly important areas include water resource management”. Another Green Party member of the Irish parliament Ciarán Cuffe, had also served as the Minister of State for the Environment, Heritage and Local Government. He used the Sweeney study to justify his statement that, “here in Ireland the effects of climate change can be summed up as ‘more floods and less spuds’. Extreme weather events such as flooding will become more common, and staple crops such as potatoes will become less viable. Changes in rainfall will leave water supplies vulnerable to weather extremes such as winter flooding and summer droughts”. The Sweeney study informed political beliefs at the highest levels in Ireland that we were to expect declines in summer rainfall so pronounced that the resulting droughts would threaten the ability to grow potatoes here.
Now that we are in the mid 2020s, it seems fair to evaluate the short term predictions of the study, which anticipated a 3% reduction in summer rainfall by this time. We are also roughly half way to the 2050s timeline that was given for the forecasted 12-17% reduction in summer rainfall. The 1961-1990 measurements used as a baseline for these predictions, reported that summer rainfall in Ireland was recorded at a long-term average of 247.5mm. A 3% reduction would imply that by now we should see average summer rainfall in Ireland at around 240.08mm. However, the long-term rainfall averages in Ireland for 1991-2020, recorded that the observed figure was 281.8mm. Far from the predicted 3% drop in summer rainfall, we actually saw an increase of around 14% as described in the table below.
During the relevant period, we have seen the precise opposite of the predicted “summer droughts”. However, it is of course mathematically possible for the 1991-2020 long-term averages to show a 14% increase in summer rainfall, and then still observe that during the 2020s the averages will have shifted significantly to arrive at an overall 3% reduction as compared to the baseline. In order to end up with this outcome there would need to be a significant number of exceptionally dry summers in the middle of the present decade. Having arrived at the mid-point of the 2020s, we can now look at the most recent data in order to check for signs of this.
For climate measurement purposes, summer is defined as the months of June, July and August. Irish rainfall in June 2025 was recorded as 100mm. In July 2025 the figure was 96mm. In the Met Éireann Climate Statement for August 2025 published just yesterday, the monthly precipitation figure is recorded as 78.1mm. This gives a total summer rainfall figure of 274.1mm for 2025, which is 11% above the 1961-1990 average. It’s not looking good for the 3% reduction in summer rainfall that the climate modelling predicted for Ireland by this time. Neither is it looking good for the forecasted 12-17% drop in summer rainfall that would threaten the viability of growing potatoes in Ireland by the 2050s. Perhaps this is why Met Éireann recently announced €2.8M in new funding for climate research relating to flooding, but nothing at all relating to drought research?
So is the great Irish spud still under threat from summer droughts, or not? When Ciarán Cuffe issued his statement on this issue, he described the context for his prediction by stating that, “we have the science, we know the impacts”. However, from his tweets since then on this topic we can understand a little more about what he means when he uses these terms.
Even as late as 2021, the former Minister of State for the Environment was still doubling down on predictions of very substantial drops in Irish summer rainfall. More importantly though, when Ciarán Cuffe says that “we have the science, we know the impacts” of climate change in Ireland, he has clarified that he really means we don’t know the impacts at all because our scientific knowledge and computer models aren’t yet sufficiently capable of predicting those impacts accurately. Instead, he informs us that we have to first wait for both scientific knowledge and computing power to increase before we can obtain stable predictions, which will not subsequently need to be updated and corrected. Of course, if anyone else expresses skepticism about the ability of climate scientists with computer models to make such predictions accurately, then Ciarán Cuffe dismissses them as a climate change denier.