Lorraine Williamson
On Friday, June 28, it is World Tree Day. The entire world pays attention on this day to the positive impact of trees on the environment. In Spanish cities where it is scorching hot in summer, trees are a proven method of lowering temperatures.
Since 1971, June 28 has been celebrated annually as World Tree Day, a date that emphasises the importance of forested areas for the development of life on Earth. The impact of trees on sustainability in the near and distant future is also considered.
Why World Tree Day?
How can trees and green spaces in cities help reduce air pollution? Trees not only beautify the landscape, but they also provide shade and play a crucial role in improving air quality in urban areas. It is well known that trees are part of essential ecosystems. They retain water, produce oxygen, and absorb CO2. In large cities, where environmental pollution is increasing, trees have an essential function in improving the air we breathe.
Trees in the city improve air quality
According to research by the University of Jaén in Spain, air pollution is a common problem in many cities. Poor air quality has negative health effects and also harms the environment. Urban forests can therefore play a crucial role in improving air quality in a city. Additionally, trees in the city act as natural filters for pollutants from electrical energy sources.
Benefits of urban trees
An article published in The Lancet Planetary Health states that nearly 90% of the population in urban areas is exposed to harmful levels of particulate matter. Green spaces in cities thus play a critical role in improving the air we breathe. Various Spanish cities are already experimenting with heat islands: green oases in the city that literally provide cooling because the temperature is lower there.
However, having many trees in the city is not the only solution for a healthier city. Cities need to take a broader approach to sustainability. They must opt for an integrated strategy, considering greening and prioritising native species. Nevertheless, urban forests and green spaces play a significant role in improving the quality of life and living conditions in the city.
Seven ways trees contribute to a healthy city
UN-Habitat, a United Nations program, has emphasised in a publication that “urban trees offer multiple benefits to cities and their residents. It is therefore essential to care for and protect the trees properly.” For World Tree Day, they published seven ways trees and urban forests contribute to a healthier city. Seven ways to make cities socio-economically and environmentally more sustainable:
- Trees increase biodiversity in a city by providing habitat, food, and protection to plants and animals.
- A mature tree can absorb up to 150 kilograms of polluting gases per year, thereby improving air quality and making the city a healthier place to live.
- Large trees are natural filters, trapping pollutants in their leaves and bark.
- Strategically placed trees in cities can lower air temperatures by 2 to 8 degrees Celsius. Properly positioned trees around buildings can reduce air conditioning use by up to 30%. In winter, they can reduce heating costs by 20%-50%.
- Studies show that living in a green environment can improve physical and mental health, reduce high blood pressure, and alleviate stress, contributing to the well-being of urban populations.
- Mature trees retain water and play a crucial role in preventing floods and reducing the risk of natural disasters. A mature evergreen tree, for example, can capture more than 15,000 litres of water per year.
- A well-planned urban landscape with abundant greenery and trees leads to increased property values. Additionally, it makes a city more attractive to tourists and businesses.
Also read: Valencia – green capital of Europe