• ‘We are likely to see a continued rise in heat-related illnesses and mortality, possibly surpassing 2022 levels,’ climate expert Peter Dynes tells Anadolu
• Researchers say rising heat-linked deaths offer clear evidence of a worsening climate emergency that is ‘an existential risk humans are facing’

ISTANBUL

As millions across Europe endure a blistering heat wave, with record temperatures triggering emergency alerts from Spain to the UK, experts are sounding the alarm over what they describe as a silent and increasingly deadly global crisis.

In recent days, temperatures in parts of southern Europe exceeded 46°C (114.8°F). In Spain’s Catalonia region, two people died and 20,000 others were placed under lockdown due to a blazing wildfire that spread at 28 kilometers (17 miles) per hour, one of the fastest ever recorded in Europe. Spain and England also recorded their hottest Junes on record.

The crisis is not limited to Europe. Last week, large swaths of the US were scorched by extreme heat, prompting the Trump administration to declare a power emergency in southeastern states to prevent blackouts as energy demands soared.

Japan also saw its hottest June since record-keeping began in 1898, according to the Japan Meteorological Agency.

“Heat waves are silent killers,” Garyfallos Konstantinoudis, a lecturer at the Imperial College London’s Grantham Institute for Climate Change and the Environment, told Anadolu.

An estimated 570 people died due to heat exposure in England and Wales between June 19-22, he said, citing preliminary data as official numbers are expected to be released next week. In Spain, initial estimates from the Carlos III Health Institute suggest that 380 excess deaths were linked to extreme heat.

Unlike floods or storms, the impact of heat waves can be invisible, and mortality cases can often go underreported, Konstantinoudis warned.

“People who die during extreme heat usually have pre-existing health conditions, and heat is rarely recorded as a contributing cause of death,” he said. “This makes the true toll of heat waves both underestimated by the public and difficult to measure directly.”

Why is Europe experiencing extreme heat?

Peter Dynes, managing director at Mirrors for Earth’s Energy Rebalancing (MEER), sees the scale of current heat extremes as deeply concerning.

“Europe is warming at more than twice the global average. This is partly due to its proximity to the Arctic, which is losing sea ice at an alarming rate. With less ice to reflect solar radiation back into space, more heat is absorbed by land and ocean, accelerating regional warming,” he said.

Europe’s land-dominated geography and shrinking rivers and lakes, especially due to ongoing droughts, also leave less water to help moderate temperatures. Since land heats faster than water, this intensifies summer heat spikes, he added.

Counterintuitively, there may also be climate feedback linked to improvements in air quality. Reductions in industrial aerosol pollution from transport and industry, as part of decarbonization efforts, mean the atmosphere is cleaner, which allows more solar radiation – more sunshine and heat – to reach the surface, he explained.

Who is most vulnerable?

Josh Foster, a lecturer in human environmental physiology at King’s College London, said heat stress can be lethal regardless of age or health.

Last month in Spain, extreme heat was linked to the death of a 2-year-old who was left in a car and a 51-year-old street cleaner in Barcelona.

However, with around 5,000 excess deaths in those aged over 70 being reported during a two-week heat wave in the UK in 2022, he said that older people face a substantially higher risk.

“Once individuals go beyond the age of 65, we start to see elevations in their risk of heat-related mortality,” he said, adding that risks are strongly associated with overall health.

Risk factors include chronic diseases like cardiovascular disease, renal diseases, or even low levels of social contact, he said.

But older individuals are not the only vulnerable group.

“Heat stress has been known to increase the risk of adverse or poor birth outcomes in pregnant women,” he said. “Strong heat exposure, frequent heat exposure, increases the risk of things like congenital heart disease, stillbirths, low birth weights and abnormal physiology in the fetus.”

According to hospitalization and mortality data, heat stress is often fatal due to cardiovascular complications, but can also lead to kidney failure and sepsis, Foster added.

Regarding precautions, he said staying out of the sun and blocking solar radiation can be very helpful.

“Electric fans are effective, but once the air temperature starts to exceed 35C (95F), they become completely ineffective, and they don’t cool the body anymore. If the air temperature is over 40°C (104°F), they can actually be harmful,” he explained.

Spraying the skin with water to mimic the effects of sweating can also provide a very powerful cooling effect, he said, while staying well-hydrated is also one of the best ways to prevent heat stress.

How many deaths can Europe expect this summer?

With this early surge of heat-related hospitalizations being reported, experts warn this summer may rival 2022, when 61,672 people died of heat-related illnesses between May 30 and Sept. 1, according to a study published in the journal Nature Medicine.

Another study by the Barcelona Institute for Global Health found that 56% of those deaths were directly linked to human-induced climate change.

“We’re likely to see continued increases in heat-related illness and mortality, possibly surpassing 2022 levels,” Dynes said, stressing that many lives depend on adaptation measures such as access to cooling, early warnings, and urban planning.

Konstantinoudis noted that atmospheric dynamics behind the current heat wave are strikingly similar to those in 2022.

“If current trends hold, we can expect persistently high temperatures, especially in southern and eastern Europe, along with potential for heat waves further north,” Dynes said. “Wildfires, flash drought,s and nighttime heat stress are increasingly part of the pattern.”

A symptom of a worsening climate crisis

Foster said recent mortality and hospitalization data offer clear signs of a worsening climate emergency.

“I think that is an existential risk that humans are facing. We climate scientists have been warning about this for decades, and we’re living in a time now where these risks again are not projections, they’re very real,” said Foster.

If global temperatures rise by 2°C (3.6°F) above pre-industrial levels, Foster estimated that around 3% of the planet will become uninhabitable for young, healthy individuals, and up to 30% for older or vulnerable populations.

Vikki Thompson, a climate scientist at the Royal Netherlands Meteorological Institute, stressed that such extreme heat, once rare, is quickly becoming the norm due to rising greenhouse gas emissions.

“Globally, heat waves are becoming hotter, more frequent, and longer-lasting due to human-driven climate change,” she said.

Western Europe has been hardest hit, she added, explaining that it has seen extreme heat waves increase in intensity “faster than anywhere else.”

“Unfortunately, this is unlikely to be the new normal, but simply a taste of what is to come. Without rapid reduction in greenhouse gas emissions, heat waves will continue to get hotter and more frequent,” she said.