Could air pollution in Cambridge be solved with these high-tech artificial trees?
Cambridge’s polluted air could be cleansed by high-tech artificial trees or ‘green walls’, Conservative county councillors have suggested.
CityTrees, dubbed the ‘world’s first biotech pollution filter’, use living plants to filter pollution from the air around them.
GreenCity Solutions, the German company behind the devices, says one of them can filter the breathing air of up to 7,000 people per hour.
‘Green walls’ are urban structures lined with trees, bushes and other greenery, which researchers say could remove 40 per cent of nitrogen oxides and 60 per cent of particulate matter from the surrounding air.
Both have been suggested by the ruling Conservative group on Cambridgeshire County Council as a way of targeting heavily polluted areas.
“A single ‘tree’ (CityTree) is able to absorb up to 250 grams of particulate matter a day and with the air purification impact of up to 275 urban trees, on a much smaller footprint,” the Tory policy on air quality states.
“Trees can be located in pollution hotspots and moved if necessary. They are particularly useful if deployed during roadwork delays, when idling traffic and consequent pollutants can be at their worst.
“Trees can also carry sponsorship, meaning they can be self-funding, or even revenue-generating.”
Over the past five years, Berlin-based GreenCity Solutions has worked with cities across Europe that are also fighting air pollution, including London and Oslo.
The vertical flat-panelled ‘trees’, the company explains, eat air pollution and double up as seats for pedestrians.
They combine a moss-powered air filter with remote technology to increase the airflow through the ‘trees’ that allows them to “suck up” and clean more air than normal, the company says.
The Conservative policy also suggests the use of green walls in ‘appropriate locations’ across the county.
‘Greening up’ streets with urban walls could reduce pollution in urban areas by as much as 30 per cent, according to a 2012 paper from the universities of Birmingham and Lancaster.
Researchers found green walls could remove 40 per cent of nitrogen oxides and 60 per cent of particulate matter from the surrounding air.
The Conservative policy states: “We will promote green walls in appropriate locations along key routes, cleaning the air in some of the worst hotspots and making some of the highways in Cambridgeshire more attractive.”
Green walls are already being used in Birmingham and London.
The county council also has a policy of planting more real trees in Cambridgeshire.
And the Cambridge Independent has launched a campaign to get 10,000 planted in the county this year.
The leader of Labour-run Cambridge City Council Cllr Lewis Herbert said that the focus should be on planting real trees and reducing congestion.
He said: “We’re in discussions with the county council, including the leadership, and we’ve got a workshop in February where we hope we will make progress on a range of measures that are needed in Cambridge to improve air quality by reducing gridlock and also tackle congestion.
“For our part, we believe we’ve got to raise a significant fund to try and improve bus services not just in the city but in the wider Cambridgeshire area.”
He continued: “It’s only going to be by both reducing vehicles and having a better bus service that we’ll give people a real alternative.”
Cllr Herbert said the Conservative policy was interesting but added that what was really needed was for all the organisations to work together on a package of measures that would make a significant difference.
Addressing CityTrees, he added: “They’re both expensive and in some cases are proved not to work. We’re focused on our plan in a very small city adding 2,000 extra trees over the next three years.
“It really is about increasing the number of trees and that’s more reliable. We’ve provided £200,000 over the next two years for tree pits because we want to put substantial trees into some of the most polluted and tarmacked parts of the city as well as in our parks and gardens.”
Last month, the county council released a draft strategy which aims to help it reach zero carbon emissions by 2050.
A motion from Cambridgeshire County Council leader, Cllr Steve Count, to increase the green canopy by “working with partners to locate, seek funding and plant at suitable locations, new hedges and trees, as well as technologically advanced CityTrees, prioritising areas around schools, and green walls in appropriate county locations” was approved.