Heat is no longer just a climate problem, it is a health emergency. This is what the World Health Organization acknowledged in its latest diagnosis, as the Earth is witnessing a dangerous and unusual rise in temperatures, to the point where it threatens human lives and livelihoods in cities and non-urban communities alike.
Today, Europe finds itself at the heart of this crisis, after recurring heat waves turned into a severe test for health systems, infrastructure and daily life, from schools and hospitals to transportation networks and outdoor work.
These waves reveal, according to experts, that the acceleration of climate change is no longer a future threat, but rather a reality that forces governments to deal with heat as a direct health threat, not just a passing seasonal phenomenon.
What is the cause of these frequent waves, what is their impact on societies, what do scientists fear, and what do global health experts advise?
What is the effect of heat stress?
The European region is the fastest warming in the world, and World Health Organization data indicate that in the past four years alone, heat has claimed the lives of more than 200,000 people, while heat-related deaths have increased by 30% over the past twenty years.
The degree of vulnerability to heat is determined based on physiological factors, such as age and health status, and other factors related to exposure to heat, such as the nature of work and social and economic conditions.
In general, the body’s inability to regulate its internal temperature and get rid of heat gained under these conditions increases the risk of heat exhaustion and heat stroke.
The body’s effort to cool itself also places an additional burden on the heart and kidneys, and as a result, extreme temperatures can exacerbate health risks associated with chronic diseases (such as cardiovascular disease, psychiatric disorders, respiratory diseases, and diabetes) and cause acute kidney injury.
Laurie Parsons, an expert in human geography at Royal Holloway College, University of London, told Al Jazeera: “Heat stress is currently the largest environmental risk in the world, with nearly half a million people dying annually from heat-related illnesses, according to the World Health Organization.”
This fact alone is enough to put people in a state of panic today, as the magnitude and nature of the health effects of heat depend on the timing, intensity and duration of the heat wave, as well as the level of adaptation of the local population, infrastructure and institutions to the prevailing climate and their ability to adapt to it.
What causes a heat wave?
France emerged as a center in the crisis, as it recorded Tuesday its hottest day in its history, according to provisional figures from the Meteo-France meteorological agency. The national average temperature reached 29.8 degrees Celsius, exceeding a record set in 2019, while one city exceeded 44 degrees Celsius.
Meteorologists report that these extreme temperatures are caused by a “heat dome,” a broad area of high atmospheric pressure that has settled over Western Europe.
This phenomenon is perpetuated by what is known as the “Omega Barrier,” an atmospheric pattern named after the Greek letter due to the similar shape it creates in the atmosphere.
Under normal conditions, the jet stream moves weather systems from west to east. In the case of the “Omega Barrier”, this flow is disturbed, leading to an air high being trapped between two low air pressure systems. This causes hot, stagnant air masses to remain trapped over the same area for days or even weeks.
For example, the British Meteorological Service stated that climate fluctuations placed Britain during this wave at the border between the high pressure system and a colder air mass located to the northwest, which created a sharp contrast between the hotter weather in the south and east, and the colder and more humid weather in the areas located to the north.
What is the responsibility of infrastructure?
Scientists have warned that Europe is particularly vulnerable because most of its housing and infrastructure were not designed to withstand long periods of extreme heat. Buildings in many Nordic countries were also historically designed to retain heat rather than drain it.
What exacerbates the situation is that only about 20% of European homes and facilities, including health institutions, schools, and care homes, are equipped with air conditioning, a percentage much lower than what prevails in the United States and countries of Asia and the Middle East, where housing and urban areas equipped with air conditioning systems are designed to adapt to the heat.
This is among the reasons behind the fact that exposure to heat in general is closely linked to social and economic inequalities and environmental vulnerability. Expert Laurie Parsons, from Royal Holloway University, noted that the effects do not affect everyone equally.
Commenting on this point, he adds that low-income communities face much greater risks of heat stress and climate vulnerability, as a result of combined factors that include poor housing insulation and reliance on physically draining outdoor jobs.
What should be done?
The data clearly show that temperatures across Europe are rising at a rate nearly twice the global average, making more and more severe heatwaves more likely in the future.
For this reason, the Director-General of the World Health Organization, Tedros Adhanom Ghebreyesus, says that it is no longer possible to be late, as leaders must give priority to investing in health systems that are able to withstand climate change, in conjunction with accelerating the pace of climate action and reducing the causes of the climate crisis.
To protect the population, the World Health Organization urges authorities to cool cities, ensure access to water and shaded areas, protect people most at risk, and prepare health systems and equipment in anticipation of temperatures rising to unusual levels.
