The ‘San Miguel summer’ is nothing new, although it is quite topical this year. However, this time the thermal increase was so extraordinary that the State Meteorological Institute issued a warning of “extraordinarily high” values for those dates. And this came after an abnormally sweltering summer. Experts do not hesitate to attribute this to climate change. To minimize health effects, cities (those affected by this effect)heat island‘), must adapt to this reality, and one of the best ways to do this is to increase the green surface. This is not an easy task as everything is very congested in big cities. The solution is to stop looking at the floor and focus on the walls.
There is evidence that vertical gardens They were used in the 4th century BC, especially in Babylonia, but also in ancient Egypt. It is the same system that can be seen today on one of the facades of the CaixaForum in Madrid: a wall that still combines different types of vegetation. Even flowers on Andalusian terraces and ivy on the facades of English cottages are other more traditional forms of vertical gardens.
This practice has many benefits in caring for the environment: the ability to maintain internal temperature both in summer and winter and, as a result, energy savingsreducing noise pollution and wind impact, improving outdoor air quality, correct management of gray water in buildings… But it also has a ‘downside’: its main disadvantage is the high cost of installation and maintenance. .
Reduce mortality rate
To guarantee the well-being of local residents, The World Health Organization recommends 10 to 15 square meters of green space per person in cities. However, many cities are far from this goal. A study by the Sustainability Observatory a few years ago warned that some 19 Spanish capitals did not comply with this guideline. This leads to serious health consequences. A report published in Lancet An estimated 6,700 premature deaths are attributable to extreme heat building up in the streets. It is also stated that one third of this could be prevented by planting trees in 30 percent of the urban area.
According to this text, the cities with the highest death rate due to heat are located in the south and east of Europe. So there are several Spanish towns on this tragic list. For example, In Barcelona, there are 8 percent trees, and the death rate due to these extreme values is 14 percent. In Madrid, these rates are between 9.5 and 12 percent.or respectively. Moreover, recent scientific studies show that the temperature increase in cities is twice the world average.
The ‘heat island’ effect causes maximum temperatures in urban centers that are 1.5 to 10 degrees higher than in rural areas.
There’s a name for that feeling of suffocation you feel in city centers in the summer (and more recently in spring and autumn): ‘heat island’ effect. Thermometers do not drop at night and it becomes almost impossible to take shelter in the shade in the middle of the day.. This is because asphalt and concrete absorb the high temperatures caused by vehicles, air conditioners and the sun and spread them after dawn, causing values over 20 degrees to continue to occur after midnight. These ‘tropical nights’ make sleeping almost impossible.
«The concept of ‘heat island’ means that the air in that area is warmer than the surrounding area. Among others, there are many factors that affect the color of surfaces: the darker they are, the warmer they are. Vegetation has, among other things, the ability to maintain itself at air temperature. “On a day when the temperature is 35 degrees in the summer, the asphalt will be 50 degrees and the vegetation will be 35 degrees,” says Consuelo Acha, an architect and professor at the ETSAM-UPM Department of Construction and Architectural Technologies. In addition, buildings prevent air flow and heat from escaping. Set results Maximum temperatures in the center of cities are 1.5 to 10 degrees higher than in the surrounding areas.
More green and less gray
So more green and less gray is needed to prevent populations from becoming uninhabitable, especially for the most vulnerable people. This challenge has been taken up by architecture, in its most contemporary form, which aims to “achieve a city model that is energy self-sufficient through renewable resources, recyclable and reusable, with clean and efficient mobility and multiple green spaces.” Arquitectura Viva magazine’s article ‘Vertical gardens: the path to sustainability’ says this.
Vertical gardens have the potential to remove up to 85% of dust and pollutant particles from the air.
To achieve this goal, The greater weight of ground plant oases should be complemented by facades dotted with leaves and flowers.. As Consuelo Acha puts it, these ‘living walls’ They can filter up to 40 decibelsThis makes them a strong acoustic insulator. They also protect buildings from thermal fluctuations and extreme weather conditions.
And if that’s not enough, Has the potential to remove up to 85 percent of airborne dust and pollution particles. There is one last advantage to consider: When these vertical gardens are installed, the value of buildings increases rapidly, both in terms of aesthetics and energy efficiency.
However, experts state that this is not the optimal solution for every situation. First of all, thanks to him high price, both during installation and for the periodic maintenance they require. Turning to cheaper options that also reduce quality can cause structural problems in houses whose weight increases significantly. So much so that in some cases it may be necessary to strengthen its structure. We should also always keep this in mind: The plant species selected must be native To ensure the survival of the region.
The plant species chosen must be indigenous to the area to ensure their survival.
Mariposa Hotel’s vertical garden is one of Malaga’s pride and has become the European reference point in sustainable urban innovation. This enormous plant carpet covers more than 100 square meters and consists of more than 3,000 plants from 15 different species. In addition to its benefits for aesthetic improvement and air quality, Reuse gray water in rooms: It includes a system that recovers it, purifies it and uses it for irrigation.
Even more famous is the one installed in the CaixaForum in Madrid, right on Paseo del Prado. Designed by prestigious botanist Patrick Blanc, it is the first facility established in Spain and features more than 15,000 plants spread over 460 square meters. These are examples of how to green and, above all, renew cities.
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REPORT. Antonio Giraldo, geographer and urban planner
“These are just one more piece for adaptation to climate change.”
Antonio Giraldo is keenly aware that the organization of cities today is mainly linked to the effects of climate change, which causes temperatures to rise rapidly in large cities during the hottest months.
-Are vertical gardens a good solution to eliminate the ‘heat island’ effect?
-Another part of the urban model focused on climate adaptation and greening. We can say that it helps, but it is not enough on its own. Although their installation in certain places can help create a more humid and comfortable environment, due to their characteristics, they are not a vital element for a problem as big as a city’s heat island. There we would be talking about a mobility model, green spaces, public space, even an urban and productive model.
-In what situations can you make the most of them?
-They have numerous benefits: in addition to being beautiful, they moisturize the environment, provide a fresher environment, create a barrier against noise and odors, clean the air and act as a reservoir for biodiversity. Getting the most out of these features depends largely on how and where they are located and, above all, on good maintenance. Of course, they will be used much more on a hard façade facing a treeless street, for example, than on the sides of motorways, where they are practically relegated to ornamentation.
-Are cities taking steps to adapt to climate change?
-Yes. What worries me is that not all of them are doing it at the same pace, and in fact, we are seeing steps in the opposite direction, in the reactionary direction, in some of them. The reality of the impending climate is grim, and the sooner we adapt, the less future impacts it will have. Moreover, those who will suffer the most from these effects will be the most vulnerable people. We must step up with a solid and fair benchmark.
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