The City That Breathes: How to Build Climate-Resilient Urban Greenery

In recent years, European cities have found themselves in a situation that, just a decade ago, seemed like a scenario from a distant future. Street temperatures are rising, heatwaves are lasting longer and longer, soils are drying out within a few hours, and water systems are unable to keep up with the rate at which rainfall evaporates. Today, cities resemble islands of heat, where biologically active space is shrinking faster than we are able to restore it. At the same time, residents’ expectations are growing: we want fresh air, shade, greenery, places to rest, cooler streets and public spaces where one can simply breathe. In the face of these expectations, the traditional approach to urban greenery – symbolic plantings, one-off actions, decorative projects – no longer makes any real sense.

This article is an attempt to answer the question: what makes urban greenery fit for the future, and what conditions must be met for it to perform its role in a world of extreme weather events? Rather than focusing on individual mistakes, we look at the entire system that determines whether a tree in the city lives or dies. We bring together scientific knowledge, urban planning, hydrology, soil biology, and CSR/ESG practice to show that lasting urban greenery is not the result of a single intervention, but of a conscious approach – a collaboration between local governments, organisations, companies and residents.

Soil as a Foundation: Life Begins Below the Surface

When we talk about greenery, we instinctively look up: at tree canopies, at leaves, at the visual layer of plantings. Yet the key to understanding why some trees grow and others decline lies underground, in the soil layer that most passers-by never see. Soil is a biological universe, where processes take place that determine water uptake, the incorporation of organic matter, root respiration, the formation of mineral compounds and the functioning of microorganisms.

In cities, however, soils are most often degraded. Years of traffic, construction, renovations and investment strip them of structure, porosity and air. They become compacted like concrete, impermeable and devoid of life. In such soil, water cannot infiltrate, roots cannot breathe, and microorganisms – those responsible for plant health – have no conditions in which to survive.

This is precisely why a young tree, planted in a way that seems technically “correct”, suddenly dies after two seasons. Not because it was planted in the wrong spot or “failed to establish”, but because, beneath the surface, it was surrounded by the conditions of a biological desert. What we cannot see is what matters most: living soil determines whether any planting makes sense at all.

Water as a Condition for Survival: Cities Must Learn to Hold on to Rain

Alongside soil, water is the second critical factor. Trees are organisms specialised in storing and transporting water, but their capacity to do so depends entirely on their environment. In cities, rainfall usually lands on impermeable surfaces: asphalt, paving, concrete. Water runs off quickly into the sewer system, leaving soil as dry as ash. The paradox is that even in a rainy year, urban trees can die of drought – simply because the rain lasts twenty minutes, while the rest of the day is dominated by evaporation.

Modern cities that genuinely want to support greenery must change this logic. Today there is a wide range of methods for retaining water where it is needed most: in watering basins around trees, in rain gardens, shallow depressions in the ground, and in soils designed to hold water for longer. Street design plays a crucial role here – whether a pavement ends with a high kerb or with an infiltration channel; whether trees have space to store water, or are “dropped” into narrow cut-outs in concrete.

Water is the cheapest and most effective factor for improving tree survival. But only if we are able to keep it on site.