The heatwave at the end of June in Europe caused 10,000 deaths

BarcelonaThe heatwave that choked much of Western and Central Europe in late June also led to a surge in deaths on the continent. According to data published by EuroMOMO – a network that, with the support of the European Centre for Disease Prevention and Control and the World Health Organization, maps excess mortality compared to other years – European countries registered more than 10,000 deaths above average during the days of the unprecedented intense and widespread heat episode.

"It is unusual for this type of excess to occur at this time of year. It is a truly high figure," Lasse Vestergaard, chief physician at Denmark's Statens Serum Institut, the seat of EuroMOMO, told Reuters. "It is difficult to explain this high excess mortality by any cause other than extreme heat," Vestergaard added. According to the data, the vast majority of these deaths are among people over 65 years old. Extreme heat can cause death either by heatstroke or by exacerbating cardiovascular and respiratory diseases.

The data – compiled from the national mortality statistics of 27 European countries – include deaths during the week of June 22-28 from all causes, not just those related to heat. However, scientists emphasize that no other significant factors were known – such as COVID outbreaks – that could have contributed to the peak of 10,650 excess deaths recorded that week, when the heatwave reached its peak in France, Spain, and the United Kingdom, among others.

In fact, scientists point out that during the eight weeks prior, mortality in European countries was, on average, about 500 deaths per week below usual levels. The same scientists have also noted that the late June heatwave would have been "virtually impossible" without human-caused climate change, which is making heatwaves more frequent and intense.

Causes of heat

This exceptional and prolonged heatwave at the end of June was the result of the combination of two factors. On the one hand, a powerful anticyclonic ridge settled over Western and Central Europe, blocking the arrival of cooler air masses from the Atlantic. On the other hand, this pattern facilitated a clear incursion of very warm North African air, originating from the Sahara, with dust and southerly winds driven by a low-pressure system located in the Atlantic.

The climate crisis and global warming cause anticyclones and warm air masses from North Africa to reach and spread across Europe with increasing ease, leading heat to reach record highs year after year. Since the anticyclone is persistent, it acts like a dome that ensures strong solar radiation for many days and a constant rise in temperatures. This explains why temperatures remain well above average both day and night.