Portugal is enduring its most intense May heatwave on record, with temperatures soaring above 40°C in the Alentejo region. The mercury hit 42.3°C in the town of Amareleja on Monday, eclipsing the previous May high of 40.5°C set in 2015. This extreme event, driven by a strong upper-level ridge and a plume of hot air from North Africa, is part of a disturbing pattern across Europe.
From a climatological perspective, the energy imbalance caused by increased atmospheric greenhouse gases is manifesting in more frequent and intense heat extremes. The planet has warmed by roughly 1.2°C since pre-industrial times, but this baseline shift amplifies the probability of record-breaking events. For instance, a heatwave that would have occurred once every 50 years in a stable climate now occurs roughly every decade in southern Europe. By mid-century, under a business-as-usual scenario, such events could become annual occurrences.
The immediate consequences are stark. Wildfire risk has escalated dramatically; Portugal’s government has placed all districts on maximum alert. The dry, hot conditions also stress water resources and agricultural systems. Wine growers in the Douro Valley report early budburst and potential yield losses. Public health advisories warn of heatstroke risks, particularly for the elderly and outdoor workers.
But this is not an isolated anomaly. The European State of the Climate report earlier this year confirmed that the continent is warming faster than the global average. The UK, France, and Spain have all experienced their own May heat records in recent years. The fingerprints of climate change are unequivocal; attribution studies consistently show that human-induced warming has made such events dozens of times more likely.
What must be understood is that heatwaves are not merely uncomfortable weather. They are physical phenomena directly linked to the Earth’s energy budget. As carbon dioxide levels surpass 420 parts per million for the first time in human history, the system is responding exactly as physics predicts: more heat trapped, more extremes. The global average temperature continues its relentless climb, and Europe is a hot spot.
Technological solutions exist, but they require political will and rapid deployment. Scaling up renewable energy, improving building efficiency, and developing early warning systems can mitigate some impacts. However, without substantial and sustained emissions reductions, the frequency and severity of such heatwaves will only increase. The science is settled. The urgency is clear. The time for half measures has passed.
