Copyright Natural Habitats 2016

Green walls putting the red light on pollution

Green walls putting the red light on pollution

bridge_blogPersistently elevated levels of pollution are common across many urban areas and cause an estimated 1.34 million premature deaths a year. Green walls are being used to reduce certain types of pollution by up to 20%…

Green walls it seems are driving a London initiative to reduce the city’s high pollution levels, which cause more than 4,000 deaths each year.

The London Department of Transport has invested 5 million pounds on a research and development program to test the effectiveness of green walls for pollution mitigation.

One outcome of this investment will be visible later this month in London’s Upper Thames Street, which will be fitted out with a green wall specially designed to trap the harmful pollution (particle matter) caused by diesel engines, tyres and brakes.

Composed of a variety of plants with different depths and textures the green wall will work by creating a range of microclimates on the walls surface to catch the tiny pollution particles. Scientists estimate the wall may be able to reduce certain types pollution of by up to 20%.

The wall will be monitored periodically and the different species checked regularly for the amounts of particulate matter that accumulates on the leaves.  The theory goes that the more particular matter on the leaves, the less inside people’s lungs.

Critics of the scheme question how big an effect the green walls will have on pollution levels.  However if such initiatives are undertaken in conjunction with efforts to reduce emissions and congestion, the overall outcome will be beneficial from not only a physiological perspective but a sustainability, ecological, psychological and amenity one too.

While New Zealand’s annual mean pollution is 14µg/m3 compared to the United Kingdom which is 23 µg/m3, the potential benefits of installing green walls at priority locations could help accelerate more successful monitoring and management of our environment.

What this exciting project demonstrates is the transition of green walls firmly into the realms of ecosystem services, where green walls provide another valuable function.  Something that Natural Habitats continues to pursue its green technology.

We are set to install an active internal green wall system in our offices in the next couple of months and will be investigating potential opportunities and locations where we can combine infrastructure and green technology in our wider urban environment. So perhaps in the not so distant future you can have something better to watch than traffic.

Check out the video on BBC  

By Lydia Franken
Landscape Architect
Natural Habitats