In an increasingly populated world, the few green spaces that remain are being replaced by concrete and block landscapes; not in vain, we all want at least one apartment where we can live. However, the urban population is increasing rapidly, and in doing so our city is becoming what is known as an »urban heat island». This phenomenon has become increasingly evident in recent decades, affecting not only the comfort and quality of life of city dwellers, but also their health.
But the problem does not end there, but these overheated cities will have a much higher climate cost than those that are not, according to a study published in the journal "Nature Climate Change."
El study, in which 1692 cities were analyzed, shows that the effects of climate change could cost urban heat islands 2,6 times moreAs this effect would cause the temperature to rise two degrees more by the year 2050. Of course, when it is so hot, air conditioning is used more and, often, it is preferred to take the car rather than walk. All in all, what we do is decrease air and water quality, leading to more illnesses and premature deaths.
Thus, the authors of the work, scientists from the University of Sussex (United Kingdom), the National Autonomous University of Mexico and the University of Vrije (Amsterdam), said that It is convenient to choose to install roofs and pavements that reflect sunlight, as well as to expand green areas in cities. This aligns with other studies on how expanding green spaces can mitigate the heat island effect.
Cities, although they only cover about 1% of the planet's surface, produce about 80% of the Gross World Product and consume about 78% of the world's energy. Furthermore, they are home to more than half of the world's population. Therefore, it is very important to take effective measures so that all these people can breathe much cleaner air than they do today. These measures are essential to address the impacts of climate change.
What is an urban heat island?
The urban heat island is a phenomenon that results in increased temperatures in urban environments compared to surrounding rural areas. This increase in temperature is most noticeable at night, which can lead to health and comfort problems, especially among the most vulnerable populations. The main causes of this phenomenon include: lack of vegetation, the presence of impermeable surfaces and heat accumulation due to human activity.
Impact on health and well-being
A study published in the magazine Science of the Total Environment analyzed the impact of heat islands on hospitalizations and deaths in five Spanish cities: Madrid, Barcelona, Valencia, Malaga, and Murcia. They found that the effect is primarily observed in minimum temperatures, i.e., nighttime temperatures, which can be up to 11.2°C higher in the city compared to its outskirts.
The researchers observed that urban minimum temperatures are directly related to the risk of mortality and morbidity. In coastal cities, this risk is more noticeable with minimum temperatures, while in inland cities, it is more associated with maximum temperatures. This highlights the importance of considering local geographic and climatic characteristics when assessing health risks associated with heat islands. These effects are significant, especially when related to the climate change in Spain. In addition, the increase in High temperatures can increase mortality.
Factors that aggravate the heat island
- Building density: Urban areas tend to have a higher concentration of buildings that retain heat.
- Construction materials: The use of asphalt and concrete contributes to the absorption and retention of heat.
- Lack of vegetation: Reducing green spaces decreases natural cooling effects.
- Human activity: The use of air conditioning and vehicles generates additional heat.
Measures to mitigate the heat island effect
It is advisable to implement strategies to mitigate the heat island effect in cities and improve the quality of life of their residents. Some of these measures include:
- Installing roofs and pavements that reflect sunlight: Choosing light-colored materials that reflect solar radiation can help reduce heat buildup.
- Expansion of green areas: Increasing urban green spaces, such as parks and green roofs, can provide shade and reduce temperatures.
- Promoting sustainable mobility: Promoting alternatives to vehicle use, such as walking, cycling, or using public transportation, reduces the heat generated by traffic.
- Climate adaptation initiatives: Implement climate action plans that include climate shelters and cool public spaces.
The implementation of cool roofs on buildings is a way to reduce the heat island effect quickly and sustainably. According to the California Department of EnergyThese covers can reduce air temperature and energy consumption, which in turn reduces CO2 emissions and improves air quality.
Furthermore, the use of reflective paint on pavements and facades can also contribute to a significant decrease in urban temperatures. These methods not only benefit the urban environment, but also create more comfortable and pleasant spaces for citizens. This strategy is essential to address the negative effects of climate change and animal health.
Climate change and its relationship with urban heat islands
Climate change intensifies the heat island effect, as rising global temperatures worsen the situation in cities. This factor is crucial, as the interaction between urban heat islands and global warming could result in an increase in the frequency and intensity of heat waves, putting people's health at risk. Studies indicate that the combination of these factors can result in abnormally high temperatures, which further affects the urban population.
The heat island phenomenon is not new; it has been studied since the 18th century. However, accelerated urbanization and climate change have increased its intensity, affecting the quality of life in urban areas. According to experts, the combination of high nighttime temperatures and heat waves pose serious health risks, including respiratory problems, heart problems, and an increase in mortality rates. The current situation leads us to wonder how much extreme heat can be tolerated.
Future prospects and importance of local research
As cities continue to grow, it is essential to conduct local research that identifies heat island effects and their relationship to climate change. This allows for the development of city-specific adaptation strategies, considering factors such as geography, culture, and urban infrastructure. In addition, it is important to understand how the investment in green infrastructure can help combat these effects.
Urban policies must integrate local studies to address vulnerability to heat waves. Community participation in the design of urban spaces can improve resilience and foster healthier citizens. In this way, we can work toward a more sustainable urban future that replaces concrete landscapes with initiatives that promote a healthy environment. This includes the use of materials that are less susceptible to heat buildup, as previously mentioned in relation to the Greenhouse.
