Paramedics help load a patient into an ambulance during a heatwave in Barcelona, Spain, in 2022.
Image Credit: Angel Garcia/Bloomberg via Getty Images
The recent heatwaves in Europe set alarming temperature records in both May and June, with July ushering in even higher temperatures. Just 50 years ago, experiencing a June heatwave was nearly unthinkable. However, escalating global warming has led to an alarming increase in the frequency, length, and intensity of heatwaves.
Heat is recognized as the deadliest climate-related factor globally, claiming around 500,000 lives annually. Even if we achieve net-zero emissions starting tomorrow, this number is anticipated to rise due to ongoing carbon dioxide emissions that continue to elevate global temperatures.
As remarked by Hugh Montgomery from University College London, “This is just the beginning.” He warns that London’s extreme heat is just one aspect of the broader climate crisis, with long-term consequences that could be profound.
Data shows that outside the tropics, the annual average of days with temperatures exceeding 32°C has increased by 12 days in the last 50 years. In Europe, which is experiencing one of the fastest rates of warming, the period of intense heat stress now typically begins in June, extending through September, with some years seeing it start as early as May.
Consequently, regions including North America, Europe, South America, and parts of Africa are currently facing an increase of up to 50 days of extreme heat stress compared to the 1970s.
Neil Maxwell from the University of Brighton notes, “The longer a heatwave persists, the longer individuals remain in that elevated physiological state.” This prolonged exposure leads to increased inflammatory responses and greater overall stress for individuals.
Prior to 1998, severe nighttime heat stress was rare, but now, regions like Western Europe are experiencing rising nighttime temperatures at a rate double that of global warming rates.
A drop in body temperature is crucial for sleep. Excessive heat inhibits the ability to fall asleep and enter deep sleep states, while prolonged nights of inadequate sleep can impair reaction times, increase anxiety, and elevate stress levels.
“Without a cooling period at night—defined as temperatures below 20°C—sustained high temperatures without air conditioning can lead to further detrimental effects,” Montgomery emphasizes.
The summer of 2022 saw record-breaking heat leading to devastating impacts across Europe. Wildfires swept through France, Portugal, and Spain; Italy’s longest river, the Po, experienced severe drought, while the Danube reached record-low levels, revealing a WWII ship laden with explosives. For the first time, temperatures in the UK soared above 40°C (104°F).
More than 60,000 fatalities were attributed to these extreme temperatures, with the highest mortality rates in Mediterranean countries such as Italy, Greece, and Spain—where temperatures also surpassed 40°C. These nations, housing some of the world’s most aging populations, are particularly vulnerable as the elderly are more sensitive to heat and generally face chronic health challenges.
“Heat exposure creates an inflammatory response, thereby triggering adverse biological reactions in the body, particularly harmful for the sick,” Montgomery cautions.
In Europe, the prevalence of heat stress days followed by tropical nights above 20°C has surged by 73% since the 1970s. These so-called “complex events” hinder the body’s ability to recover during the night, exacerbating heat stress.
Furthermore, Europe is experiencing prolonged heat stress more frequently, and in Africa, the likelihood of encountering extreme heat lasting more than three-quarters of the year has nearly tripled.
US leaders, including former President Donald Trump, have pledged to plant millions of trees amid rising CO2 emissions. Trees can significantly mitigate urban heat by creating shaded areas and facilitating moisture evaporation from their leaves, resulting in cooler surroundings. Neighborhoods with dense tree canopies can be up to 10°C cooler than comparable regions lacking such coverage.
Despite ongoing tree-planting initiatives to combat heat, a recent study indicates that many areas still lack sufficient canopy cover, leaving over 90% of buildings in cities like Paris and London below the 30% threshold necessary to effectively counter the dangerous urban heat island effect.
Topics:
- climate change/
- abnormal weather
Source: www.newscientist.com
