A park in the Providencia municipality of Santiago, Chile, with only a handful of trees NurPhoto (NurPhoto via Getty Images)
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Santiago de Chile peaked at 35.6 degrees this Thursday, but its seven million residents don’t deal with high temperatures that well. How tolerable the week-long heat wave is depends on whether the person is in a community with tree boardwalks or concrete boardwalks. The lack of green spaces can cause temperatures to rise by two to three degrees. Of the 52 municipalities in the metropolitan area, only eight meet the minimum limit of 10 square meters of green space per inhabitant recommended by the World Health Organization. Most of them are concentrated in the most prosperous areas, in some cases there are as many as 18. However, half of the areas, especially in the outskirts where people with lower incomes live, have areas under five according to the system of urban planning indicators and standards (SIEDU). To address this injustice, the regional government has launched a plan to plant 30,000 native trees over the next two years, kickstarting a project that aims to create 200,000 new plantations.
The Urban Trees program is planting an axis of 20 kilometers of trees in 34 green space-deficient communities, benefiting half a million residents. Cultiva Corporation, which is dedicated to reforestation and environmental education, will have 2,000 million Chilean pesos ($2.5 million) to plant 11,000 trees in public spaces and deliver 19,000 to civic organizations, which will be trained in their proper care. This Wednesday, the architecture and urban planning team was formed that will be responsible for defining the benefiting communities and the tree species that will be used, taking into account criteria such as fairness, heat waves and concentrated particulate matter, among others.
The Nueva Alameda-Providencia architectural and urban redevelopment project, which begins in the center of the city, is part of the tree-lined urban plan. It begins in the municipality of Providencia, one of the most expensive areas to live with, with 14.9 square meters of green space per inhabitant, and continues its journey through the municipalities of Santiago, Estación Central and Lo Prado, one of the driest areas in the region, with 3.2 square meters of green space per inhabitant . Matías Herceg, Managing Director of Cultiva, clarifies that the plan will not necessarily go through all the communities mentioned above.
If a decade ago Chile suffered six heat waves a year, in 2022 it was more than 60. Santiago in particular, surrounded by hills, is a city where the emanation of gases cannot circulate smoothly. The aim of planting green lungs is not only to provide shade to combat heat waves, but also to absorb fine dust.
The first trees of the project will be visible from April, with the goal of ending with 10,000 to 15,000 new trees this year. Currently, Cultiva is considering planting Quillay, Huingán, Quebracho, Maitén and Peumo. Considering that the South American country has been going through a mega drought for 14 years, the water requirements of the plantations are crucial. Herceg explains that when making selections, it is crucial that they are native species with low water consumption. There are areas where the water only arrives once a week in cistern trucks, for example.
“We will work with municipalities to find out how much irrigation costs they can absorb and if they have potable water or can change their waterways. If support is needed in the transition from the plantation to a permanent tree, it will be supported from the Cultiva program or from the regional government,” emphasizes the NGO’s executive director, who sees this issue as relevant but not critical.
The metropolitan governor, Claudio Orrego, assured at the launch of the program that due to the fact that heat waves hit the residents of the most vulnerable communities harder than the others, it was decided to plant 200,000 new native trees “where they are concentrated the heat islands. The original plan, which is responsible for Cultiva, calls for 30,000 new trees and will later continue with the 170,000 “through other lines,” Orrego said. In December, the agency announced on Radio Duna that 100,000 new ones would be planted by 2024. This newspaper tried unsuccessfully to speak to the governor to find out the details of the macro project.
Architect Francisco Schmidt, former adviser to the Ministry of Housing and Urban Planning and head of the Urban Parks Program, highlights the initiative, like others more local, born from plantations, but warns of the lack of maintenance that these have and that, in addition to water scarcity, ending in barren areas. “It is one thing to plant and another to water, control, manage so that it bears fruit. Especially when you think of native species, where many grow more slowly,” says Schmidt, who would like more ambitious numbers for new trees because of the climate catastrophe.
“Urban islands produce radiation that when it announces 33 degrees, it is actually 35 degrees. A very drastic and profound innovation must be demanded,” says the architect. While maintaining proportions, look at what has been done in Melbourne (Australia) where nature has been reintegrated into the city, including the restoration of riverbeds, inter-city parks, rain gardens, porous pavements. For those skilled in the art, the city tree plan should initially focus on the course of the Mapocho River and the streams present in Santiago.
A study published this Wednesday in The Lancet, using data from 93 European cities (home to 57 million residents over the age of 20), cited in this article in EL PAÍS, found that almost 6,700 premature deaths are due to heat islands, a Phenomenon where asphalt and concrete absorb heat during the day and release it again at night, increasing the temperature compared to places with green areas. The document concluded that a third of those deaths could be avoided by planting trees in 30% of urban space.