In Italy we don't know how to use public green to fight the heat

In Italy we don't know how to use public green to fight the heat

At the beginning of the seventies in Turin there were 3.5 square meters of public green for each of the 1.1 million inhabitants. Fifty years later, while the human population has decreased (850 thousand registered people), plants have increased more than exponentially. Eighteen million square meters and 167 thousand plants (excluding the hills) make up the publicly managed heritage of the Piedmontese capital, equal to about twenty square meters per inhabitant, a value that exceeds double the minimum threshold recommended by the World Health Organization. But can green be used to combat climate change and the drought of these days? The answer is yes. Let's see how.

The dramatic images from space that tell the extreme heat Gallery 4 Images by Luca Nardi

Look at the gallery As air conditioners “Trees do not absorb only carbon dioxide, an important task but which dominates in public discourse all the others - tells Giorgio Vacchiano, researcher in forest management and planning at the University of Milan -. There are many others that are rarely talked about. They have, for example, cooling effects through evapostraspiration, comparable to our sweating: it is limited to a perimeter of a few tens of meters, but very strong, almost like two air conditioners: and in fact, the streets surrounded by trees show temperature values even six or seven degrees lower than the others ". Then there is the absorption of up to 20% of fine dust, according to some studies; the slowing of heavy rains, which thanks to the vegetation do not reach the ground all together, causing damage from floods; mental and social well-being.

According to Vacchiano, every euro invested in trees produces three or four in terms of public benefits, be it less use of electricity to cool buildings or the health of citizens: “We must consider them an investment. Think of Turin, which a year ago published the Strategic Green Infrastructure Plan, a document where vegetation is not considered a mere embellishment, but a real asset ". How? “For example, by crossing the data of the most vulnerable population with those of heat islands, ie the areas where the temperature reaches its peaks - says the expert -. This work serves to insert more vegetation exactly where it is needed, especially in areas particularly inhabited by the elderly ”. And from the poorest shares of the population.

Drought emergency, here are some tips to save water The consequences of the lack of rain are there for all to see, and the municipalities are starting to ration water and suggest ways to avoid wasting it "The PNRR gives us money, but for the green there is no land ”But it's not that simple. In the city and in the province it is difficult to find spaces for seedlings. “My office has twenty-eight million euros to spend to insert seven hundred thousand plants on seven hundred hectares - he tells Gabriele Bovo, manager of the metropolitan city of Savoy, the old province-. This year? We only found 160. In the next few I don't know ”. Bovo offers an explanation: “Small municipalities, which have large areas, prefer to give them to farmers. An understandable discourse on an economic level, but this is not the way to think about the community ”. How does it come out? "It must be the Ministry of Ecological Transition to write to the Municipalities with its own authority, and to do so without asking, simply, if they are interested in collaborating: the PNRR is a national objective, and individual local officials cannot be left to seek these land. It seems strange, but someone even accuses us of waging a personal battle. "Government crises do not help.

When it comes to water, drought is not the only problem in Italy Affecting the scarcity of resources water is also the fact that a third of the water that enters the aqueducts is dispersed before reaching the taps Bottlenecks: why the funds risk not arriving When, then, it is decided, it is often necessary to correct the rota. "The Pnrr has dedicated 330 million to the planting and maintenance of trees in the fourteen metropolitan cities - confirms Vacchiano -. But there is a problem: those who calculated the minimum areas to access the funds have definitely overestimated the values. According to the tables, Milan must plant trees at least on 138 hectares, and this is one of the bottlenecks: finding these surfaces is very difficult ". Thus, the call is likely to fail.

But it is not just a question of space. Also missing are the trees. "The other bottleneck is that Italian nursery production is absolutely underpowered and insufficient to supply all the seedlings we would need: it is necessary to invest scientifically in nurseries with a long-term operation, even starting to experiment with what they are. the species or varieties most adapted to the climate to come. And this can only be done in a protected context like that ", says Vacchiano.

Less hydroelectricity and dry fields: the economic consequences of drought The lack of water impacts various companies, from the production of hydroelectric plants to agricultural enterprises of the Po Valley, considered the area most affected by this crisis A land register of trees and no greenery in the suburbs But then - we ask - how do you get out of it? What are the policies to be implemented? " cities of the world, Fao certification assigned to 138 cities in the world, six of which are Italian (Cesena, Lignano Sabbiadoro, Milan, Modena, Padua and Turin, ed) - says Vacchiano -. be mapped and monitored. Then, have a green office, that is a specific delegation within the municipal council to deal with this aspect. Of course, and this is the third point, dedicated resources are needed, which can be i, as seen, can generate a return. The public hand alone is not enough: Milan, for example, also involved companies with the Forestami project. "

Finally, it is necessary to have a plan." As with all resources, the only way to obtain them the full benefit is knowing what to do, for example by replacing the plants we are used to with native vegetation more suited to climate change. Not only. It is also possible to select plant mixes that can help each other, for example by creating better humidity conditions. The important thing is not to confine the greenery to parks or suburbs: because the benefits are mainly local, and if we place it too far away, citizens will not be able to reach it ", continues the expert.

Sometimes, the territory offers unexpected resources. "This is what happened in Milan - says Enrico Fedrighini, city councilor and historical voice of Milanese environmentalism. "The city is rich in water underground, which has three layers. The drinkable one is drawn from the last two, located several tens of meters underground, while the first is used for agriculture. Not only that: every year Metropolitana Milanese, the company that manages subways and water services, is forced to suck up forty million cubic meters of water to prevent them from invading the tunnels: it is a resource that, with the appropriate works, could be used for city irrigation and beyond. Instead we convey it to the south of the town. But recently, even after our report, the Municipality has taken a first step, removing the ban on night-time watering of the vegetation ”. Which, otherwise, would dry up, nullifying the entire path (and investments) made over the years. "Today in Milan we have a unique opportunity to work on the integration of services - concludes the environmentalist -. Last week the formal assignment for twenty years of municipal green management to Metropolitana Milanese, which already takes care of the water service: and this opens a window of opportunity that we must exploit by planning. To get to ban the word 'emergency' ".

The problem of Carpi (and small towns) If the avant-gardes are starting to move, an organic strategy for the country cannot wait. In Italy there is a national plan for adaptation to climate change, dating back to 2018, but it is still in a draft state: it is urgent to finalize its drafting and make it operational. “The problem is above all that of small and medium-sized cities - concludes Vacchiano -. They are left aside, and, in reality, they are the ones that struggle most to find the skills, the resources to enrich their green heritage. The news in recent days have spoken of Carpi as hotter than Italy. But, paradoxically, it is not on the radar ”.

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