Let’s rethink our cities and make them a greener place. Having more urban green spaces contributes to an enjoyable city climate and a healthy environment. With this post I hope to inspire you to start dreaming about greener cities and get some ideas of how to contribute to the creation of green urban spaces.
It is July and in my home city temperatures are already approaching 30°C degrees at 9 am in the morning. The dark coloured streets and concrete walls warm up quickly and I can feel the heat released by all the cars stuck in the morning traffic. Cycling this morning, I can’t stop thinking about how nice it would be to escape the hot and sticky city during the hot summer months.
The term of urban heat island comes to my mind. The annual mean air temperatures in large cities can be significantly higher than in the surrounding countryside; in a large city with one million inhabitants or more mean temperatures are usually around 1 to 3 °C higher as compared to the surrounding countryside. In the evening the temperature difference can even be as extreme as 12°C.
Energy resulting from the people living in the city, their cars, their busses and all their other machinery creates excess heat that gets trapped in the city. Roads and concrete buildings have often replaced the vegetation. The resulting lack of evapotranspiration is another reason for the high city temperatures.
The past few summers were among the hottest and driest ever recorded in Europe. With this trend likely to continue, summer becomes a season to fear rather than to look forward to. With temperatures far above 30°C degrees, living and working in a city becomes a burden to most of us.
Green Urban Spaces: Inspiration from the Botanical Garden
Today, my workplace is the botanical garden. The botanical garden is always a source of inspiration and I am grateful that I can work here among the beautiful plants and shade-giving trees. All of a sudden, summer feels a lot nicer. The cars disappeared and instead of the roaring engines, the comforting sound of buzzing insects surrounds me. The air is a lot cooler here and feels fresher. Being here feels like being in an oasis.
I love coming here for a few hours of work or sometimes just for a stroll. I get inspired and I learn. Botanical gardens can teach us a lot about their plant residents. Within a relatively small area, we can find a large variety of little ecosystems that accommodate a multitude of plant communities.
Botanical gardens are designed in such a way that a lot of different plants can grow there. Some of these plants naturally wouldn’t even occur in the area. They can only grow there because of the carefully planned set-up of the garden.
When designing a botanical garden, we have to pay a lot of attention to the local (climate) conditions. Local conditions are variable and vary even within the relatively small area of the garden. There are areas with stronger wind gusts, areas with full mid-day sun, shadowy areas, wet areas and dry areas.
Different conditions come with different plants but different plants also create different conditions. With careful planning we can change the local conditions and adjust them to our liking. This has a huge potential for the planning of green urban spaces. And apart from being good for the city climate, green urban spaces also are aesthetically appealing. They can even have a positive impact on our psyche.
Change the Microclimate with Green Urban Spaces
Trees and bushes can provide shade for delicate plants, protective fences and hedges prevent wind damages. Mulch cools the soil and can protect the roots of a plant. Concrete walls store heat and provide a warmer climate for heat-loving plants. A little pond cools down the surrounding air through evaporation. At the same time it provides a habitat for water plants. These are just a few examples of how we can actively influence the microclimate and adjust local conditions.
As we can see with the current issue of climate change and global warming, manipulating the climate on a large scale is not that easy. Or at least it is not easy to change it the way we want it to be. Managing the microclimate, however, is actually quite straightforward and we know quite well how to do it. If you have a garden and like gardening, you probably know that.
The term microclimate is somewhat ambiguous and can refer to several square kilometres or just to a few square meters. Only a few trees can already have a noticeable effect on the microclimate. Just think about the relief you feel when you sit under a shade-giving tree during a hot summer day instead of sitting in the full sun. Air temperatures in green urban spaces, such as city parks, can actually be around 2°C to 8°C lower than in other urban areas. Moreover, this cooling effect can even extend into the urban area surrounding the park.
We already have a lot of knowledge of how to change the climate on a local scale. We just have to use it and make it a priority in urban planning.
Green Urban Spaces instead of Grey Urban Spaces
Right now, urban areas are growing and cities are under pressure to accommodate all the people living there. As a consequence, buildings are getting taller, while living space is getting smaller. Concrete walls and a network of busy roads dominate most cities. Green spaces often have to vanish for the sake of new buildings, roads or parking areas.
It seems that cars are integrated in our modern life a lot more than green areas. Despite the fact that our lives depend on these green spaces, we put a lot more thought into where we can park our car than where we can plant a tree.
So let’s dream a bit! We got so much used to cars being present everywhere. But imagine how our cities would look like if the majority of cars would disappear. Green urban spaces that are accessible for everybody would dominate the cityscape. We would create these spaces by transforming roads and parking areas into parks, gardens, and other recreational nature areas
Cycling paths would wind in between these areas. With most of the cars gone, convenient public transport and cycling would become more attractive. Instead of starting your day being stuck in traffic, you would start your day with a ride through nature.
Such a city transformation would not only be beneficial for the city climate but also for the environment and people’s health. It may seem a bit utopian and it will not happen over night. But more and more cities and urban planners are working towards greener and more sustainable cities. By thinking about how we would like our future cities to look like, we can become a part in this development. It doesn’t have to be perfect from the beginning.
Green living Roof Tops and Vertical Gardens
So let’s start small! To start with, we can focus on the places that we don’t really use anyways: the roofs and walls of all the buildings. Transforming conventional roofs into green living rooftops is a great way to make use of neglected spaces in the city and make them meaningful. Green rooftops have many benefits. They contribute to better air quality and an improved microclimate. If applied on a larger scale, they can help reducing the urban heat island effect and cool down the city during hot summer months.
They also provide a habitat for many small animals including insects and birds and can thus increase the local biodiversity. Many animals suffer from the habitat loss caused by rapid urbanization. Why not try giving them some of their habitat back?
Find a list with the top 10 benefits of living green roofs here.
But not only roofs offer a great potential to make our cities greener. Walls do too. Climbing plants could transform concrete facades into vertical gardens. Balconies and windowsills could be turned into miniature gardens where flowers, herbs and even fruit and vegetables thrive.
Who wouldn’t like to have some homegrown food? Apart from environmental benefits, green roofs and walls are visually appealing and watching plants grow on your roof, balcony, wall or window is fun and will make you feel more connected to nature.
Get started and inspire!
It’s easy to get started. Grow some flowers on the windowsill, plant a climbing plant that will transform the facade of your house in a vertical garden or turn your roof into a green roof. The effect might seem little but don’t let yourself discourage by that. Every bit counts. Actually even talking about the importance of green urban spaces has a positive impact. With your actions and your ideas you will inspire other people and contribute to a change of thinking.
There are a lot of things we can do to increase the amount of green urban spaces. However, to change things on a larger scale and more fundamentally, we also need the support of our political leaders. Nature has to be prioritised over short-term economic benefits. The creation of green urban spaces has to become a fundamental part of urban planning.
Let’s set an example together! Whether you are an individual caring about your city and the environment, a green company, an environmental organisation or another institution with a green mission and a green vision, we can all contribute to the green city transformation. Let’s talk about nature in the city, let’s inspire, let’s rethink our cities and let’s transform grey spaces into green spaces.