The climate crisis increases the threat of heat-related deaths, especially in urban areas. In the urban continuum of the Barcelona Metropolitan Area, at least half a million people live in areas that are very vulnerable to heat, according to data from a study on the climate vulnerability index, prepared by the Urban Sustainability area of the Institut Metròpoli.
The concentration of paved surfaces in cities produces the phenomenon known as a heat island: at night the center and certain parts of the city register higher degrees than the periphery and the rural area that surrounds them. In addition to cement, the city's own activities, such as road traffic or air conditioners, also enhance the increase in temperature.
Excessive and sustained heat leads to an increase in mortality and morbidity, especially in the most vulnerable groups, such as the elderly, newborns or people with cardiorespiratory diseases. In the case of Barcelona, a heat wave is considered to occur when maximum temperatures exceed 33.1ºC for three consecutive days or more.
The characteristics of each neighborhood and its situation in the city mean that the vulnerability of the neighbors changes depending on the area where they live. Data from the Barcelona Public Health Agency allow us to see which neighborhoods in the Catalan capital have the highest risk of mortality.
With only one degree of increase in temperature during a heat wave, some neighborhoods such as Dreta de l'Eixample, Salut, Carmel, Putxet and Farró, and Horta show a mortality risk that exceeds 10%, according to data from the Public Health Agency of Barcelona (ASPB).
On the other hand, areas such as Besòs and Maresme, Nova Esquerra de l'Eixample, Bordeta, Hostafrancs and Pedralbes present a smaller, albeit significant, risk.
For the metropolitan area as a whole, the Metropoli Institute's data are the ones that allow a greater approach to the phenomenon. Their data identifies that the 9 municipalities most vulnerable to episodes of extreme heat are those with the highest population density: Badalona, Barcelona, Montcada and Reixac, Sant Adrà de Besòs, Santa Coloma de Gramenet, l'Hospitalet, Cornellà, Esplugues and Sant ox
In the Barcelona Metropolitan Area, many municipalities do not reach the standards recommended by the World Health Organization, which suggests between 10 and 15 square meters of green areas per inhabitant.
