The heat in Córdoba intensified over the last two decades due to the phenomenon of urban heat islands.
This phenomenon refers to areas of cities where it is hotter than in the outskirts or nearby rural areas.
In particular, this occurs due to the concentration of buildings and pavement, and in Córdoba capital it affects 44.8% of the surface of the city.
This is indicated by a scientific study from the National University of Córdoba, which revealed that between 2003 and 2022, the nighttime temperature increased by an average of 1.01 degrees.
The research, published in The Journal of Climate Change and Health, analyzed the temporal and spatial dynamics of urban heat islands using satellite maps and on-site information.
The results confirmed that most areas experienced significant temperature increases. 12.8% of the sites suffered more heat during the day and night.
Cement and buildings retain heat
Urban heat islands are not coincidental. They are generated by buildings, the excess of asphalt and cement that retain the sun’s heat.
Also influencing are the increasing traffic, air conditioners, and the heat released by industries. The absence of trees and vegetation to cool the environment worsens the problem.
“The most marked trend in these two decades is a generalized nighttime warming,” explained María Lila Asar, a researcher from the Mathematics Department of the Faculty of Exact, Physical, and Natural Sciences, to UNCiencia.
Rural areas cooled by 1.23 degrees due to crop irrigation. This widened the thermal gap with the city.
Alarmingly different temperatures in Córdoba
During December nights, the average temperature is just over 16 degrees in rural areas.
However, in the more urbanized areas of Córdoba, the heat reaches 22 degrees.
That is, almost six degrees of difference between the countryside and the city. The warming is stronger in areas with a high density of buildings.
The study concluded that 89% of the population is exposed to increased nighttime heat. More than a third suffer from heat both day and night.
A high proportion of households with unsatisfied basic needs are among the most affected by this phenomenon.
The health and environmental consequences of heat islands
The urban heat island effect modified the structure of urban ecosystems in Córdoba, which also favors a greater presence of mosquito vectors of diseases, such as Aedes aegypti (dengue).
Therefore, in recent years the life of mosquitoes and their eggs has changed due to the longer time with high temperatures.
Additionally, the evapotranspiration of plants also increased due to the high temperatures.
“For the body to rest, the ambient temperature must drop below 25 degrees,” Asar told UNCiencia. With the city experiencing the heat island effect, reaching that threshold is more difficult.
Heat waves, combined with the urban island effect, intensify discomforts related to high temperatures.
On the other hand, climate change may alter the seasonal distribution of rainfall in Córdoba.
The solution to the heat in Córdoba lies in the trees
According to the researcher, the best way to mitigate the urban heat island is with woody vegetation. Trees and shrubs have proven to be a key mitigator by generating a significant cooling.
“We need to plant a lot to help mitigate the effect of urban heat islands,” Asar indicated. More native trees and shrubs are needed.
These help provide shade and are resistant to the particular weather conditions of Córdoba. Vegetation emerged as the main tool to reverse the increase in temperature in the city.
The research team was led by Dr. Elizabet Lilia Estallo. Scientists from the Institute of Biological and Technological Research, Conicet, and the National University of Córdoba participated.
