How much green space does it take to be happy?

15 April 2026, by Kley/Red.

Photo: UHH/Bruns

The University of Hamburg is the scientific home to more than 6,200 researchers. Every 2 weeks, we offer a glimpse into their work as part of the “Research and Understanding” series in the Hamburger Abendblatt. Prof. Dr. Stefanie Kley explains why gardens and trees make our lives more fulfilling and why cities benefit from them in particular.

When the trees turn green again in the spring, I think we all look forward to seeing the first colors after winter; we feel happier, and many of us feel better than we did during the dark winter months. For me, however, this effect of nature is not just a personal observation, but a fascinating research question.

As a sociologist, the central themes of my work are social inequality and its consequences. While I can hardly shed my own social background, changing one’s physical environment is often possible. In academia, we refer to the residential environment as a so-called “opportunity structure”—and I’m interested in the extent to which people can move a step closer to achieving their life goals by choosing where they live.

Positive Impact on Mental Health

My team and I place a special focus on the importance of a green living environment for well-being in the city. We want to find out whether a lack of green space drives people to move away from their neighborhood. In doing so, we also examine whether there are differences between people in various life stages or whether this perception depends on social status.

Numerous findings from experiments indicate that spending time in nature and observing trees or passing clouds have a positive effect on mental health. This is also confirmed by one of our current projects, in which we statistically analyze interviews in diary form. We relate the described nature experiences, which were collected in the U.S., to positive as well as stressful events and health impairments. Initial results show that people generally benefit from spending time in nature in their daily lives—regardless of their age, gender, or ethnic group. This is particularly evident in good emotional balance when people spend time together in nature.

However, given the current housing shortage, there are efforts—especially in major cities—to build ever more densely and allocate fewer green spaces. How this affects residents’ satisfaction and whether it might even lead them to move away has hardly been researched to date. That is why my team and I want to find out whether—and if so, for whom—a green living environment is particularly relevant.

In Hamburg, green spaces are more evenly distributed

To this end, we conducted 1,800 telephone interviews in Hamburg and Cologne, asking, for example, how people use the green spaces in their neighborhood, but also whether they can see trees and other greenery from their windows. For Hamburg, we found that there are hardly any differences between social classes when it comes to views of green spaces, because green spaces are more evenly distributed—even in residential areas where less affluent people live. This is different in many cities.

Overall, however, our results show that for working-class people, a green living environment is significantly more important for residential satisfaction than it is for wealthier people. One factor that may play a role here is that those who do not have as much money generally live in smaller apartments. However, a green view from the window enhances even small rooms, and a good-looking green corridor or a nearby park can offer opportunities for free physical activity in nature.

Our survey therefore scientifically confirms that people in large cities derive quality of life from a green living environment, and that many people compensate to some extent for the noise and congestion of the city by spending time in green spaces within walking distance. And what is particularly relevant: people who can do this are less likely to transfer their thoughts of moving away. We interpret this as an indication that green courtyards and gardens, street trees, and parks could counteract urban sprawl—that is, the expansion of cities toward their outskirts. These findings can provide important insights for urban and land-use planning regarding the preservation of green spaces.

(This content has been translated automatically.)