The importance of urban nature for human and environmental health is increasingly recognised in urban planning. However, when talking about urban nature, the focus is often on leisure trips to green spaces or greenery in residential areas. These aspects are important but can leave a significant proportion of greenery exposure overlooked. As we typically spend almost an hour and a half per day on the move, greenery exposure during everyday trips also matters. Everyday trips can provide a significant proportion of our daily greenery exposure.
A new study by the Digital Geography Lab at the University of Helsinki, published in the Computers, Environment and Urban Systems journal, examined the potential for greenery exposure and its spatial variation in daily walking trips across 43 major European cities. In Finland, the Helsinki metropolitan area was included in the analysis.
The study focused on trips to secondary schools, which represent a typical everyday trip often made on foot. Walking to school has been shown to have positive effects on young people's well-being and sustainable travel choices throughout their lives, so studying the travel environment quality of school trips is particularly important.
"Our results show a link between better walking access and lower exposure to greenery in European cities," says Dr. Elias Willberg, the lead researcher of the study. "We believe that the link is due to dense urban development, which typically associates with better walking access, while leaving less space for other land uses, such as urban nature," he continues.
There was a wide variation between European cities in both the walking access to secondary schools and the greenery of journeys. Cities in northern Europe typically have greener travel environments compared to southern European cities. However, seasonal variations change the overall picture as there is also more variation in the North.
"Although seasonal variation is an obvious factor influencing the amount of greenery, it is rarely empirically considered in greenery studies, which may bias the perceptions of which cities are considered green," says Robert Klein, who is preparing a doctoral thesis on greenery exposure and mobility in the GREENTRAVEL project.
From a sustainability perspective, the results of the study offer no simple solutions. Promoting walking access is important for sustainable mobility, but there are also obvious climate and health benefits from increasing urban nature, as well as benefits for pleasantness and biodiversity. Fortunately, greener environments also promote the use of sustainable travel modes. In this context, solutions can be found, for example, in redistributing street space to sustainable travel modes and street greenery, and in new ways of providing greenery, such as green roofs and walls.
"For urban planning, it is important to recognise more holistically the benefits that greening of travel environments can offer. In cities, there is always a struggle for space, so it is important to identify diverse benefits and availability of greenery. The comfort and well-being that greenery brings is one of the less explored themes in our travel environments. It would be best if city dwellers did not always have to go to a green space separately to enjoy a beautiful row of trees or a flowerbed," concludes Professor Tuuli Toivonen, who is leading the GREENTRAVEL project.
The study is part of the multi-year GREENTRAVEL project (2023-2027), funded by the European Research Council (ERC), which investigates the health and well-being impacts, spatial patterns and inequalities of exposure to greenery during travel. The project involves cities across Europe and is developing new ways of mapping greenery and its health impacts using tools such as virtual reality, mobile big data, street view imagery and artificial intelligence. The research was also funded by the European Union's Horizon 2020 programme through the URBANAGE project.
Original article:
Willberg, E., Fink, C., Klein, R., Heinonen, R., & Toivonen, T. (2024). ‘Green or short: Choose one’ - A comparison of walking accessibility and greenery in 43 European cities. Computers, Environment and Urban Systems, 113, 102168. https://doi.org/10.1016/j.compenvurbsys.2024.102168