Western Europe is enduring a severe heatwave, disrupting daily life across many countries. On 24/6, France recorded an average daily temperature of 30°C, the highest since records began in 1947. Over half of the nation is under a red heat alert, the highest level in many European countries, with tens of thousands of households in the west experiencing power outages.

The UK and Spain both recorded their hottest June days since 1950. In Italy, 16 red alerts are in effect, primarily in the northern and central regions.

According to scientists, the current heatwave is driven by a weather pattern called the "Omega block". This pattern consists of a large high-pressure area situated between two low-pressure systems. This structure can remain stable for days, or even weeks, making it difficult for other weather systems to move in. This trapped high-pressure area creates conditions for a heat dome to form over much of western and central Europe, effectively turning the region into a "furnace".

A resident cools off by a fountain near the Eiffel Tower in Paris, France on 24/6. Photo: AP

"Heat domes are essentially high-pressure systems that remain almost stationary for several days, trapping dangerous heat and humidity below," Mireia Ginesta, a climate researcher at the Smith School of Enterprise and the Environment in the UK, told AP.

According to Ginesta, high pressure means air is sinking to lower atmospheric levels. "As air descends to lower altitudes, it becomes compressed. Pressure increases, and the temperature rises accordingly," Ginesta explained. This process causes the air below to become progressively hotter. Concurrently, high pressure reduces cloud formation and weakens winds. With less cloud cover, more solar radiation reaches the ground. The accumulation of heat over consecutive days creates prolonged hot spells, also known as heatwaves.

"Heat domes are phenomena that occur in the upper atmospheric current, while heatwaves are the heat we feel directly on the ground," said Jennifer Francis, a climate scientist at the Woodwell Climate Research Center in the US. Heat domes can also lead to thunderstorms characterized by heavy rainfall, strong wind gusts, and hail.

A heat dome causes hot air to accumulate at ground level. Graphic: Washington Post

Experts emphasize that this is a natural phenomenon, not exclusive to Europe. In recent years, similar heat dome events have occurred in the US, Canada, Australia, and South Asia. However, amidst continuously rising global average temperatures, the same weather pattern can now produce significantly higher temperatures than in the past.

According to the Copernicus Climate Change Service of the European Union (EU), the global average temperature is currently about 1,4°C higher than pre-industrial levels. Europe's increase has reached about 2,4°C, making it the fastest-warming continent globally.

"Almost all of this heat originates from the human-induced greenhouse effect due to fossil fuel emissions, while the actual distribution of this excess heat depends on many factors," Ben Clarke, a researcher of extreme weather and climate change at Imperial College London in the UK, told AFP.

Beyond global factors, certain regional characteristics also make Europe more sensitive to climate change. One such factor is Europe's proximity to the Arctic, which is warming faster than the rest of the world, with an increase of about 3,2°C compared to pre-industrial times, according to Copernicus.

The warming of the Arctic is accompanied by a phenomenon known as the "albedo effect". As ice and snow melt, darker surfaces like land and ocean become exposed, absorbing more heat than reflective white surfaces. This increases the amount of heat retained within the climate system.

Carlo Buontempo, director of Copernicus, stated that many areas in Europe that once experienced regular freezing winter conditions no longer maintain that state. "This means darker land surfaces are exposed more, rather than being covered by white snow," Buontempo explained. As the ground absorbs more solar energy, regional temperatures continue to rise.

Another factor is the decline in aerosol pollution in Europe over recent decades. Aerosols are tiny particles suspended in the air that can reflect some sunlight and increase cloud reflectivity. As aerosol levels decrease due to environmental policies, more solar radiation reaches the Earth's surface.

"Reducing air pollution is important for respiratory health, but it also increases the amount of solar radiation at the surface, as many types of particulate matter in the air tend to deflect sunlight," expert Clarke noted.

Temperatures in western Europe on 24/6. Graphic: CNN

Koh Tieh Yong, a lecturer at the National University of Singapore, told Channel News Asia that heat domes are inherently a natural atmospheric mechanism, but noted a potential link between this phenomenon and climate change. According to Koh, global warming, particularly the accelerated warming in the Arctic, can weaken powerful high-altitude jet streams, thereby creating more favorable conditions for heat dome formation.

Liz Bentley, director of the UK Royal Meteorological Society, shares this perspective. "Climate change is certainly making heatwaves more frequent, intense, and prolonged than they were previously," Bentley stated.

As Tam (According to AP, AFP, Reuters)