Robot trees a 'costly and ineffectual gimmick', says atmospheric scientist

€350k ’robot trees’ installed in Cork to clean pollutants from the air have sprouted calls for 1m real trees to be planted instead
Robot trees a 'costly and ineffectual gimmick', says atmospheric scientist

Five high-tech moss-covered 'CityTrees' are being installed at Patrick’s St and on Grand Parade in Cork to tackle air pollution. Picture: Cork City Council

Controversial €350,000 ’robot trees’ installed in Cork to clean pollutants from the air have sprouted calls for 1m real trees to be planted across the city instead.

Five high-tech moss-covered 'CityTrees' are being installed at Patrick’s St and on Grand Parade to tackle air pollution.

The moss filters harmful pollutants like fine dust particles and nitrogen oxides from the air and ‘eats’ it, making it a sustainable fine dust filter.  

The CityTrees also have in-built sensors to collect air quality data and TV screens to share information about air quality in the city. They also feature a built-in chair to act as street furniture.

Cork City Council said the CityTrees form one part of its strategy to tackle pollution, which also includes the planting of 1,300 trees this year.

“These are not there to replace a tree. A tree takes in carbon dioxide and releases oxygen," said David Joyce, operations director, Cork City Council.

“These CityTrees take in particulate matter — dust — from diesel engines, from burning fossil fuels, and it captures that dust and eats the dust so it takes 80% of that dust out of the air.

"And they’re multi-purpose, they provide high-quality seating and 40in TV screens which will be used to disseminate information about air quality in Cork City," he added. 

But scientists, activists, and politicians now say that many thousands of real trees are now needed in Cork to absorb carbon dioxide, filter other pollutants, cool down the city in summer, boost biodiversity, and improve people’s mental health.

Other cities including Glasgow and Madrid have advanced plans to plant millions of trees. 

Some 18m  trees are being planted in and around Glasgow over the next 10 years and Madrid is planting a 75km urban forest around the city.

"If Glasgow can plant 18m trees than surely Cork can plant 1m trees," An Rabharta Glas councillor Lorna Bogue said.

"Or if we wanted to be more ambitious, we could plant a continuous forest around the city like they’re doing in Madrid.

“There are quite a few groups which have been working on these ideas for a while. If robot trees could be the impetus for all these groups and activists to coalesce around the one plan it would be very good.”

Ms Bogue said that she was pleased but not shocked by the vocal reaction to the ‘robot trees’.

The idea of robot trees have really captured people’s imaginations. If you saw them on a TV show you’d think they were a very heavy-handed metaphor but it’s actually happened.

The €350,000 CityTree project is paid for from a €55m National Transport Authority funding package announced under the July stimulus plan to support pedestrians and cyclists.

But atmospheric scientist Dean Venables said that the devices are “a costly and ineffectual gimmick”.

Dr Venables, a researcher at the Centre for Research into Atmospheric Chemistry at University College Cork, said that Ireland's core strategy has to be to reduce emissions.

He said that although the CityTrees may clean the air in the immediate vicinity of the structures, they would have no discernible impact on overall air quality in the city.

“The most important strategy has to be to reduce emissions," he said.

"You need to stop emissions of carbon as well rather than capture them and try to claw back."

"Burning solid fuel — coal, peat, wood — causes the worst pollution in Cork City. In the city centre, during the day, the main problem will be traffic fumes. Ireland has a large diesel fleet which produces particulate matter and nitrogen oxide," he said.

CSO figures show that 50% of people use cars to travel less than 2km — a distance that most people could easily walk or cycle.

Rapidly reducing our reliance on polluting vehicles is one vital step to decarbonising and cleaning up our city, Dr Venables believes.

"While I am critical of the CityTrees approach, what is positive is that air quality is recognised as an issue by the city council. 

"As a result, Cork has the most innovative national approach to air quality monitoring with a netowork of low-cost sensors throughout the city. 

"Monitoring air quality will not, by itself, improve air quality but such measurements are the first step to raise awareness of the importance of air quality as a major public health issue."

Air pollution is responsible for up to 1,300 deaths in Ireland each year, according to the Environmental Protection Agency.

And the recently published Intergovernmental Panel on Climate Change report found that climate change was widespread, rapid and intensifying and poses very serious threats to all regions.

Green Party councillor Dan Boyle said that Cork City Council has increased the number of trees it plants annually from 100 two years ago to 1,300 this year. He hopes that this will soon increase to tens of thousands.

A tree officer was recently appointed by the council and is due to start in the coming weeks.

"I think we’re going in the right direction," Mr Boyle said. "I’m hoping that a tree officer will have expertise and bring about a more in-depth tree planting policy."

Architect Kevin Smyth, who has been working on plans to green the city, said that a major tree-planting project would take support from someone in central government or a CEO or mayor in local government with both the vision and power to deliver such a project.

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