We covered in the past the importance of green areas in packed urban locations, as they can cool down the atmosphere better, while also helping with the way water is dispersed in a city.

The green spaces problem is especially obvious in Europe's large cities, which fought with one on the worst summers last year in terms of heatwaves.

As per The Guardian, city authorities say that planting more trees isn't always an option in these areas, since pavements, tall buildings and underground parking lots make it near impossible to add new green life to a city.

Experts say that a lot of large urban settlements in Europe have fewer green areas than they had a century ago, while pollution and traffic is on the uprise.

Christophe Najdovski, the deputy mayor for revegetation and green spaces on Paris city council, said that "it’s a massive challenge. We know with enough trees we can lower the city’s summer temperature by up to 8C. They’re basically natural air-conditioning. But planting them isn’t always easy."

Experts from the Intergovernmental Panel on Climate Change argue that trees help in many ways, both storing these dangerous gases, while lowering the ambient temperature, making it less necessary to use air conditioning units, which in turn, reduces energy consumption.

Scientists also say that trees help "improving mental and physical health", while aiding air quality, again, an especially important thing in traffic-packed cities.

Some European cities lost as much as 10% of their green areas since the early 1990s' and the main cause for the fall of trees, according to specialists, is the fact that most of them are reaching their end of life, due to the fact that they were planted in the 19th and 20th centuries.

Adding more trees to a city landscape isn't as easy as just buying and planting them, says Ana Luisa Soares.

Trees require a big financial effort, one that's needed

The landscape architect from the University of Lisbon says that a single tree can cost an administration as much as 2.000 euros over half a decade.

"You need to buy the tree. You have to plant it, water it – especially in the first five years, when it is most vulnerable. Life is hard for a tree in a city: compacted soil, polluted air … You have to maintain it, treat it for disease. When you’re talking tens of thousands of trees, it’s a huge investment."

Still, despite the high cost and implications, city dwellers need trees for many of the reasons stated above.

"They are important for all of us, residents and visitors. They give us more shade, better air quality, lower temperatures, natural beauty – basically, more trees mean happier people. We know this. And they will be even more vital in the future", Soares said.

Officials from the European Commission proposed a draft last year, demanding city, town and suburban authorities to have at least trees planted across 10% of their surfaces by 2050 and to also prevent the loss of existing green spaces.

Parking spots making room for more trees

A potential solution found by some cities is removing, at least partly, parking spots that are located between boulevards and sidewalks.

Christophe Najdovski said that "essentially, we aim to significantly reduce the space reserved in Paris for cars, and to use as much of it as we can to plant trees: a massive revegetation program, the reconquest of nature over the automobile. The objective is to plant trees in large numbers and wherever possible."

Having already planted some 38.500 trees since 2020, Paris' city council aims to plant a further 21.000 this winter.

Some residents complain that newly added trees are reducing the amount of natural light, making the electricity bill more expensive in turn, but having trees is crucial in an ever-warmer Europe.