Regions of Western and Central Europe, including Spain, France and the United Kingdom, have activated red alerts as a heatwave is expected to intensify, with temperatures projected to exceed 40°C in the coming days.
In France, more than 50% of its areas are currently in the highest meteorological alert stage, which has led to the closure of hundreds of educational institutions.
The French territory experienced Tuesday, June 23, as the hottest day in its history, with 44.3 °C recorded in Pissos, Landes. At the same time, authorities confirmed the deaths of at least 40 individuals who drowned while swimming in unsupervised areas in recent days.
“The dangers of swimming in places without supervision during a period of intense heat should not be underestimated,” warned the Minister of Sports and Youth, Marina Ferrari, in an interview with a radio station in France.
The minister highlighted that a large number of citizens sought relief from the heat in rivers and canals, disregarding the risks associated with these practices.
One of the victims was a 13-year-old girl who, without knowing how to swim, accompanied her family on the River Seine, near Fontaine-le-Port, on the afternoon of Sunday, June 21st.
Drownings were also reported in Germany, a country where forecasts indicate that temperatures could reach 40 °C in the west and southwest by the end of this week.
The Spanish State Meteorological Agency (Aemet) issued a warning about “exceptionally high” temperatures for this season, exceeding the usual average by five to ten degrees, with projections of up to 44 °C in certain locations.
In the Basque Country, specifically in San Sebastián, a red alert was triggered with an expectation of maximum temperatures of 40 °C, a level that represents almost double the average for this period of the year.
The Met Office, the United Kingdom’s meteorological service, issued a red heat warning, considered rare, for Wednesday and Thursday in areas of England and Wales, with forecasts of up to 38 °C in certain locations.
Similar red warnings were also issued by authorities in Italy, Switzerland and Luxembourg.
The direct origin of this thermal rise is identified as a ‘heat dome’: a vast mass of hot air that leaves the Sahara desert, moves north and remains parked over the European continent, trapping the heated air in its area.
This climatic phenomenon is enhanced by a robust high atmospheric pressure system, popularly called “African anticyclone”.
Impact of climate change on increasing extreme heat
Climate experts say the increasing frequency of heat waves is an unmistakable sign of human-induced climate change, resulting primarily from the combustion of coal, oil and gas.
Météo-France points out that, of the 51 heat waves documented in the country since 1947, an impressive 34 were observed from the year 2000 onwards, with 26 of them occurring only from 2011 onwards, showing a significant acceleration of the phenomenon.
The British Met Office calculates that the probability of extreme heat, such as that seen in recent heat waves, is currently ten times greater due to climate change, indicating that these events are becoming not only more severe, but also prolonged.
It is observed that, over the last half century, the temporal extension of hot periods has experienced an increase of almost 100%.
Akshay Deoras, researcher at the National Center for Atmospheric Sciences at the University of Reading, in England, clarifies that “global warming of anthropogenic origin acts as a catalyst for this phenomenon, enriching the atmosphere with additional heat and raising extreme temperatures to much higher levels than would previously be seen.”
However, the key element behind this occurrence, as the expert adds, lies in what is called the “heat dome”.
Understanding the heat dome phenomenon
Deoras describes the “heat dome” as a “gigantic atmospheric barrier that prevents cloud formation, allowing intense solar radiation to heat the Earth’s surface continuously, day after day.”
He continues: “Simultaneously, air moving downward under the influence of a high-pressure system is compressed and heated, in a process analogous to what occurs with air in a bicycle pump during use.”
In essence, the phenomenon constitutes a portion of hot air that persists motionless in a specific area, thus retaining individuals on the surface in a prolonged heat episode.
The scientific community suggests that such occurrences are triggered by sudden changes in ocean temperatures.
Consequently, the rise in water temperature contributes to warming the air, and wind currents drive this heat to continental regions.
Upon reaching the continent, the hot air is confined by a high pressure system, which generates a kind of dome flanked by low pressure systems.
This high pressure intensifies the heating of the air column by compressing it, functioning, in practice, as a dome-shaped thermal barrier.
Future scenarios and challenges facing climate change
In recent years, historic heat waves have manifested themselves on a planet that, on average, is approximately 1.4 °C warmer compared to the end of the 19th century, a phenomenon widely attributed to human activities, such as the combustion of fossil fuels.
However, if global climate policies maintain their current course, global warming could reach around 3°C by the end of this century.
Such a scenario will unquestionably result in new thermal records, presenting significant obstacles, especially for nations such as the United Kingdom and Switzerland, whose infrastructure and buildings were not designed to withstand extremely high temperatures.
Friederike Otto, professor of climate science at Imperial College London, warns that “the current climate environment differs substantially from the one in which we grew up. Our structures and infrastructural systems are, unfortunately, inadequate for the challenges that lie ahead.”
Until 1990, the record for maximum temperature in the United Kingdom in any month of the year was 36.7 °C, a mark established in 1911.
Since that period, this mark has been exceeded on several occasions, and the current national record reached 40.3 °C, recorded in July 2022.
As climate change progresses, even higher temperatures could materialize, as warned by Richard Betts, head of climate impacts research at the Met Office and professor at the University of Exeter.
He concluded: “Until we can reduce global carbon emissions to net zero, global warming will persist, and new temperature records will continue to be set.”