Trees and forests in a city center supply clean air to citizens and reduce the temperature of the city by reducing the urban heat island effect. A tree absorbs 150 kg (330 lbs) of carbon dioxide per year, helping combat climate change. It also prevents landslides and soil erosion, and contributes to the conservation of biodiversity by protecting the habitats of wild animals and plants living in the city. Urban green spaces also play an important role in promoting citizens’ health, emotional stability, and well-being. Tree planting is a cost-effective and nature-based solution to various issues in the city, and it brings economic benefits, too.


Many cities are paying attention to the importance of green spaces in cities, increasing eco-friendly spaces and carrying out activities to protect parks in city centers.

The United Nations Economic Commission for Europe [UNECE] is carrying out the “Trees in Cities Challenge” which urges European cities to participate in combating climate change by planting trees.

The representatives of each city agree on the profound impact of urban forests and green spaces on sustainable development, and make a pledge to plant a number of trees within 2024. Currently, more than 60 cities around the world are participating. In addition, Freetown in Sierra Leone, Africa, carried out activities with the goal of planting 1 million trees in the city through the “Freetown the Treetown” campaign.

In line with this global movement, ASEZ is continuously planting trees in each city.

On November 24, ASEZ university students in Cordoba, Argentina, carried out cleanups and planted trees there. Valeria Antonucci, a coordinator from the government of La Rioja, Argentina, expressed her gratitude and said, “The first step to get neighbors into the good habit of keeping green spaces clean and taking care of our environment is to set a good example.” Gisela Rodriguez, a student at the National University of La Rioja, said, “I feel very grateful for being able to transform a space that was abandoned for a long time. I hope the future generations will enjoy these beautiful trees that we have planted today.” The volunteer activity was disseminated in the newspaper, informing the importance of planting trees to the residents.

With more than 80% of global GDP generated in cities, cities also emit more than 70% of the earth’s carbon dioxide. Cities take a considerable responsibility for climate change, and are very vulnerable to inland and coastal flooding, rising temperatures in cities, heavy rain, drought, water shortage, and pollution.

It is impossible for a city to achieve sustainable development without forests and trees.

According to the UN, more than half of the world’s population lives in cities, and by 2050, nearly 7 of 10 people will live in cities. Cities are responsible for environmental issues and have the key to changing the future of mankind. Cities and citizens, who are at the forefront of combating climate change, must take action.

“Until you dig a hole, you plant a tree, you water it and make it survive, you haven’t done a thing.”

― Wangari Maathai