Heat island: what is, causes, consequences and solutions

When we talk about infrastructure, we refer to elements such as Buildings, streets, sidewalks and asphalt. These surfaces They retain heat more efficiently than open and natural spacessuch as fields or forests. In addition, the Lack of vegetation in cities It reduces natural cooling capacity through water evaporation.

On the other hand, Human activity in urban areas It also contributes to the urban heat island effect. The use of heating or air conditioning systems, energy generation, industry and transport produce heat as a byproduct. In addition, the Greenhouse gas emissions and other pollutants trapped in cities contribute to air warming.

These combined factors create a kind of “bubble” of heat over urban areas, where Temperatures can be several higher degrees than in nearby rural areas. This effect has several negative impacts on the urban environment and in the people who live in it.

The construction materials used in cities, which are often dark, absorb more solar energy, which makes certain areas of the city more prone to the effect of heat island. This effect is slow, so you can keep hot air for several hours in this type of areas.

It occurs in densely populated cities that prioritize construction over natural ecological balance. In addition to the fact that they do not appear constantly throughout the day, the clear skies and sunny days favor that the hot air remains on certain areas for longer.

However, not all cities in the world have a heat island effect. The geographical location and mountainous structure of the cities that accompany it can affect the occurrence of this phenomenon.

We encourage you to also read these other articles about the difference between heat and temperature and heat waves: what are, temperatures, causes and consequences.

The heat island effects mainly due to two main causes: the geometry and composition of urban areas. These are the main causes of this thermal problem:

• The geometry of cities contributes to the heat island effect. High and narrow buildings in urban areas create urban cannons, where narrow streets and nearby buildings block the air flow and limit wind circulation. This prevents heat dispersion and catch hot air near the surface, increasing temperatures.
• The composition of urban areas also plays an important role in the heat island effect. Hard and artificial surfaces, such as asphalt, concrete and dark roofsThey have one High solar heat absorption capacity. These surfaces retain heat during the day and release it slowly overnight, which maintains the highest temperatures.
• The lack of vegetation in cities It aggravates the heat island effect. Green spaces, such as parks, gardens and trees, provide shade and water evaporation, which helps reduce temperatures. On the other hand, in urban areas, vegetation is reduced due to urbanization and infrastructure growth, which reduces natural cooling capacity.
• Human activity It also contributes significantly to the heat island effect. Anthropogenic heat sources, such as the use of heating and cooling systems, energy generation from fossil fuels, industry and transport, release additional heat to the urban environment. These heat sources increase the air temperature and contribute to the general heating of urban areas.
• Greenhouse gas emissions and other pollutants released by human activities in cities contribute to the increase in this effect. These gases catch heat in the atmosphere, creating an additional heating effect on urban areas and increasing local temperatures. Here you can read about what are the greenhouse gases and where they come from.

The urban heat island effect has negative impacts on the lives of people and the environment:

• Higher energy consumption: The temperature in the city is higher, especially on summer nights. This leads to a greater demand for energy for air conditioning, which in turn increases electricity prices.
• Health effects: High temperatures can affect the health of urban residents, causing general discomfort, respiratory problems, insolation, dehydration, fatigue and even an increase in insolation mortality.
• Increased air pollution: The heat island worsens air quality because carbon dioxide emissions and other pollutants, such as sulfur dioxide (SO2) or nitrogen oxides (NOX), are responsible for the greenhouse effect while the consumption of fossil fuels increases.
• Economic Impact: The heating effects associated with the urban heat island effect could double the economic losses provided by climate change.

To minimize the impact of the urban heat island effect it is necessary to bet on sustainable urban development, as proclaimed by the United Nations themselves through the new urban agenda. Among these solutions we find:

• Bioclimatic buildings: including the installation of renewable energy sources such as solar panels to promote photovoltaic self -consumption or plant cover to reduce heat gain, and the installation of passive cooling elements to create more efficient homes.
• Sustainable Infrastructure: Cities must update their buildings, roads, bridges, sidewalks, stations, light posts and more to align with the fight against climate change.
• Sustainable mobility: Cars are one of the main causes of urban pollution, which in turn contributes to the increase in temperatures. For this reason, mobility must be prepared for the future and work hand in hand with new technologies.
• Green tax: Tax on the emission of carbon dioxide, other greenhouse gases and pollutants, aimed at taxing the actions harmful to environmental health and that allows compensating the externalities of urban economic development.
• Ecobarrios: We talk about new urban developments that seek to reduce the impact on the environment by changing the way of life of the inhabitants. To do this, more green spaces, public spaces renew and promote environmental education.
• Green runners: These spaces also have different social, cultural or sports uses and can connect the city’s natural spaces with extensive vegetation stripes. It is also possible to mention elements such as urban orchards at this point.

Little by little, the causes of this heat island effect should be reduced so that it does not affect us in our health and the environment. Now that you know more about the urban heat islands and the serious problem they suppose, we encourage you to start taking small steps in your home to contribute to reducing this problem. There are thousands of things that can be done globally, government, business and citizen. For example, from home we can take into account how to refresh the house without air conditioning and the use of plants that absorb heat to decorate our home.

If you want to read more articles similar to Heat island: what is, causes, consequences and solutionswe recommend that you enter our category of climate change.