More than 4% of deaths that occur in cities during the summer months are associated with high temperatures and heat waves. If trees cover 30% of a city’s surface, it could cut deaths by a third.according to a modeling study published in Lancet under the direction of the Barcelona Institute for Global Health (ISGlobal).
The results, based on data from 93 European cities, highlight the significant benefits of planting more trees in cities to mitigate global warming.
Heat waves are associated with premature mortality, cardiorespiratory disease, and hospitalization. However, moderately high summer temperatures can also contribute to these problems.
Cities are the places most vulnerable to this reality.. Less vegetation, higher population density, and impenetrable building and street surfaces cause temperature differences between the city and surrounding areas. This phenomenon is known as the “urban heat island” and due to the climate crisis, it could worsen in the coming decades.
ISGlobal researcher and first author of the article, Tamara Ungman, confirms to SINC that “all cities tend to be heat islands, but there are many differences within the same city. For example, when we say that parks are the lungs of a city, we also mean that they provide cooling.”
The study notes that the places with the highest heat deaths were in southern and eastern Europe. “Spain is one of the countries with cities that has the biggest impact on mortality associated with urban heat islands,” Jungman explains. Most affected cities Barcelona, Malaga, Palma de Mallorca, Madrid, Seville and Valencia. “All these cities have a fairly low percentage of tree cover,” the expert adds.
Towards a Comprehensive City Model
More than a century has passed since the city planner Ebenezer Howard founded the garden city movement which sought to challenge the modernist distinction between “industrial cities” and “bedroom cities”. In this regard, Jungman notes that “it’s important to start thinking about cities more in terms of people and less in terms of cars.”
It is important to start thinking about cities more in terms of people and less in terms of cars.
The study highlights the significant benefits of planting more trees in an urban space. However, the authors acknowledge that the layout of some cities may make it difficult to plant trees. Therefore, it must be combined with other alternatives such as green roofs to reduce temperatures. For the most compact and dense urban areas, Jungman suggests “lowering the target to 25% and supplementing it with other strategies such as vertical gardens, green roofs and replacement of impervious surfaces such as asphalt on vegetable surfaces.
This move towards integrated urban plans could bring great benefits, “including improved mental and physical health, in addition to the environmental benefits themselves, ”says the scientist. On the contrary, the continuation of current patterns could lead to serious health problems for the residents of these areas.
“Projections based on current emissions indicate that heat-related illness and death will be a major burden on our health services in the coming decades,” Jungman said. “Our task is to convey to those responsible for the local administration the benefits of combining green areas in all microdistricts to promote a more resilient, sustainable and healthy urban environment“, Add marknieuwenhuysendirector of the ISGlobal Urban Planning, Environment and Health Initiative.
Nieuwenhuijsen led a group that estimated the death rate of residents aged 20 and over in 93 European cities. A total of 57 million people between June and August 2015. The researchers also collected data on daytime temperatures in rural and urban areas for each city. First, they modeled a hypothetical scenario without an “urban heat island” to calculate premature mortality. Second, they estimated the reduction in temperature due to the increase in tree cover. up to 30%as well as preventable deaths.
Protective action of trees summer and hot
Cities were on average 1.5 degrees hotter than its surroundings summer 2015. Some 6,700 premature deaths can be attributed to rising urban temperatures and heat waves, accounting for 4.3% of total deaths during the summer months and 1.8% of deaths during the year. A 30% increase in tree cover would lower temperatures, avoiding a third of these deaths. total 2644 people died.
Areas with more people are areas with the lowest percentage of trees that are
“Our results also show the need to conserve and care for the trees we already have because they are a valuable resource and new trees take a long time to grow. In addition, it’s not just about the number of trees, but how they are distributed,” Nieuwenhuysen says. In this regard, Jungman notes that “areas where more people live are areas with the lowest percentage of trees, indicating that the population does not benefit from them and the impact will be greater.”
The analysis was done with data from 2015 because population data for more recent years were not available, but as Jungman points out, the results can be generalized and the study provides important information for adapting our cities and make them more resilient to the effects of climate change.
“Here, we are only looking at the impact of trees on temperature, but increasing green spaces in cities has many other health benefits, including increased life expectancy, reduced mental health problems, and improved human cognitive function,” the scientist adds.
For Antonio Gasparini, professor of biostatistics and epidemiology at the London School of Hygiene and Tropical Medicine, co-author of the study: “Vulnerability to heat varies from one city to another depending on several factors. Understanding the benefits of policies such as increased forest cover can help take action to reduce risks and prevent preventable deaths. Especially with climate change.”
This article was first published on SYNCHRONIZATION
Source: Hiper Textual
