Why does urban green infrastructure matter?

Let's take a closer look at Europe¹ (with similar trends worldwide):

• 75% of Europeans – and well more in the future – live in or around cities.
• City dwellers are exposed to pollutant levels exceeding EU air quality standards, in particular particulate matter (PM) and ozone (O3), with road transport being a significant source.
• Half of the EU's urban population is exposed to traffic noise levels above 55 dB. 
• Cities emit 69% of Europe's CO2.

As these phenomena is not limited to the EU only, it is evident that a large part of the world’s population is now looking to move to a city, or lead their life in an urban metropolitan area; and at the very least will have to become totally dependent on food and other products drawn from renewable resources. (Swedin, 2013²).

Why green infrastructure and how does it help?

The quality of life in cities clearly depends considerably on environmental conditions in the surroundings and beyond.

Green infrastructure reduces the amount of stormwater and treats it at source, and can mitigate the frequency and intensity of unwanted events. In dense urban environments, properly planned and managed green areas can also help improve air quality and reduce excessive heat.

The list of benefits green infrastructures can bring to urban areas is long and comprehensive:

- Reduced and delayed stormwater runoff 
- Enhanced groundwater
- Storm water pollutant reductions
- Fewer sewer overflow events
- Increased carbon sequestration
- Urban heat island (UHI) mitigation and lower energy demands
- Improved air quality
- Additional wildlife habitats and recreational space
- Better human health
- Higher land values

Every step counts – from large scale to small site greening

Case “Rotterdam” seeks to restore the “sponge function” of the city:

The Rotterdam Climate Change Adaptation Strategy aims to make Rotterdam climate-proof by 2025, and focuses on three key aspects: 1) maintaining and strengthening existing infrastructure (dykes, barriers, sewers), 2) adapting the entire urban environment using nature-based approaches, and 3) working together with other city projects to link adaptation measures and spatial development.

And as Hartje (2013) describes in the case of New York City, every full vegetated acre of green infrastructure would provide total annual benefits of $8,522 in lower energy consumption, $166 in fewer CO2 emissions, $1,044 in improved air quality, and $4,725 in increased property value.

Strategic placing of green infrastructure - creating healthier urban environments

The strategic placing of trees and other green infrastructure can reduce the UHI effect and cool the air by between 2 ºC and 8 ºC, reducing heat-related stress and premature human fatalities during high-temperature events³.

Source of photo: Vincent Callebaut Architectures

While it is desirable to employ trees to control air pollution, it is not always easy to plant trees in a densely populated city. For example, 64% of New York City constitutes an impervious area, with this rate reaching as high as 94% in districts like midtown Manhattan. The green roof can serve as a solution to this dilemma, since it makes use of rooftops, usually 40–50% of the impermeable area in a city⁴.

Read more about why municipalities demand more green roofs here. 

The Urbanscape product portfolio offers much to improve green infrastructure elements with the aim of creating healthier urban environments:

1. innovative and easy to install system with high water retention capacity designed specifically for landscaping areas such as residential gardens, golf courses, commercial spaces, cemeteries and parks. 

2. innovative, lightweight and easy to install system with high water retention capacity designed specifically for light-weight green roof on residential, non-residential and industrial buildings in urban areas.

To learn more about available Urbanscape systems, download our brochures below:

• [1] Published in: SOER 2015 – The European environment – state and outlook 2015/European briefings / Urban systems
• [2] Swedin (2013). Urban Development and the Environmental Challenges – “green” systems considerations. Cities of tomorrow – Thematic issue papers.
• [3] Doick and Hutchings, 2013. Air temperature regulation by urban trees and green infrastructure. Research note.
• [4] Yang, J., et al., 2008. Quantifying air pollution removal by green roofs in Chicago. Atmospheric Environment 42 (2008) 7266–7273. 

Blog written by Darja Majkovič, PhD