The human body is remarkably adaptable. Throughout history, our species has been able to acclimatize to both severely cold and extremely hot climates. This ability has allowed the colonization of virtually every corner of the planet. However, we must not forget that, despite our adaptation, There are clear limits to our tolerance for extreme heat.
Climate extremes can be detrimental, and it is precisely these extremes that will define existence on our planet unless we manage to mitigate global warming. According to a recent study, By 2050, an additional 350 million people are expected to suffer from heat stress compared to current rates.This phenomenon is linked to an increase in disease, so it is essential to understand the importance of public health in the face of heat stress.
Tom Matthews, a climatologist at Liverpool John Moores University and the study's lead author, along with a team of researchers, examined 44 of the world's 101 most populous megacities. Their analysis revealed that Heat stress has doubled with a 1.5 degree Celsius increase in global temperatureConsidering that the average temperature of the planet is likely to increase by 2 degrees Celsius, More than 350 million additional people will be living under heat stress by 2050This phenomenon is linked to the increase in the frequency and intensity of heat waves as global temperatures continue to rise.
To reach this conclusion, the researchers used advanced climate models to observe how warming projections would affect heat stress conditions. Their findings suggest that even if we manage to limit global warming, Megacities such as Karachi in Pakistan and Kolkata in India will continue to face annual conditions similar to those experienced in 2015, when heat waves claimed the lives of 1200 people in Pakistan and more than 2000 in India..
The study's results are alarming, as they indicate that the world's cities are at serious risk due to their high density of asphalt and concrete, which absorb heat, raising temperatures in urban centers above those in rural areas. This increase in temperature exacerbates the impact of heat stress and can be devastating for public health.
According to a NASA report, Heat stress is one of the leading causes of climate-related deaths in many countries.. This phenomenon has more than doubled in the last 40 years. Colin Raymond of NASA's Jet Propulsion Laboratory says that the Wet bulb temperature is a crucial indicator for understanding heat stressThis measurement represents the lowest temperature to which an object can cool when water evaporates from it. This becomes a vital factor, as it indicates the human body's ability to cool itself through sweating. The higher the wet-bulb temperature, the more difficult it is for the human body to regulate its temperature, which can result in serious health implications.
What is the limit that the human body can resist?
Studies suggest that The highest wet bulb temperature that humans can withstand when exposed to the elements for at least six hours is approximately 35 degrees Celsius.When these levels are reached or exceeded, it becomes virtually impossible for the body to regulate its temperature, which can lead to physical collapse.
Since 2005, wet-bulb temperatures exceeding 35 degrees Celsius have been recorded on several occasions in subtropical areas, such as Pakistan and the Persian Gulf. Research also indicates an increase in the frequency of these events. Additionally, temperatures between 32 and 35 degrees Celsius have more than tripled in the past 40 years, raising concerns about heat stress in the population.
Which regions of the world will have to face this phenomenon?
Although it is not easy to predict when we will reach wet bulb temperatures above 35 degrees Celsius on a regular basis, climate models suggest that Certain regions will face these conditions in the next 30 to 50 yearsThe most vulnerable areas include South Asia, the Persian Gulf, and parts of eastern China and Southeast Asia.
As for specific regions, it is estimated that by 2050, areas of Spain such as Madrid, the Valencian Community and Andalusia will experience temperatures above 35 degrees Celsius for more than three months a year. However, these regions will not be as exposed as other parts of the world where humidity is higher, exacerbating heat stress. This phenomenon can also be observed in places that have experienced unusual heat waves.
The situation becomes even more worrying when one considers that climate change is causing shifts in weather patterns, increasing the frequency and intensity of extreme weather events, including periods of drought and extreme heat waves.
In the long term, it is expected that The combination of these phenomena is linked to an increase in deaths associated with extreme heat, along with an increase in heat stress-related illnesses.The World Health Organization (WHO) estimates that by 2050, climate change could lead to up to 250,000 additional deaths per year due to heat stress, respiratory and cardiovascular diseases, and malnutrition.
The relationship between heat stress and urbanization
Large cities present a particular challenge when it comes to heat stress. Most metropolises experience a phenomenon known as urban heat island effect, where temperatures in the city center are significantly higher than in surrounding rural areas due to the concentration of buildings, asphalt, and other heat-absorbing materials. This phenomenon creates an environment where extreme heat can be even more dangerous, reinforcing the importance of understanding how the heat island effect may influence public health.
Urban areas are also often more vulnerable to drought and lack of clean water, further exacerbating the situation. Cities that lack sufficient green infrastructure, such as parks and tree-lined areas, are particularly susceptible to these problems, as they lack the natural mechanisms that help moderate temperatures.
Adaptations are essential to mitigate these impacts. Governments and cities must develop plans.
- Create green spaces: Adding parks and recreation areas can help reduce local temperatures and provide cool refuges during heat waves.
- Implement early warning systems: These can inform the public about extreme heat events and recommend protective measures.
- Reorganize urban space: Modifying urban planning to allow for better ventilation and airflow can help mitigate the heat island effect.
- Promote public education: It is essential to inform citizens about how to protect themselves during periods of extreme heat and what measures to take to maintain their health.
A comprehensive approach that considers the needs of the population and the existing infrastructure in each city is essential. Failure to do so could lead to a significant increase in heat-related health problems among the population.
Experts warn that without urgent action to reduce emissions and mitigate global warming, the number of people affected by heat stress will continue to rise. This poses not only a risk to public health but also economic complications. The cost of medical care will increase, and labor productivity will decrease dramatically, especially in sectors that rely on outdoor labor. It is vital to adopt measures to mitigate the impact of heat stress. heat stress in animals, since a healthy ecosystem contributes to human health.
Over time, climate change could lead to mass migrations as people seek to escape extreme conditions. This movement could generate social and political tensions, as well as conflicts in areas already under pressure due to other social, economic, or environmental factors.
The transition to a more sustainable world is urgent. It is necessary for both governments and citizens to take action to address the causes of climate change and adapt to its effects.Collaboration between nations is essential in the fight against global warming and heat stress, which is expected to increase in the future.
