Cork's controversial ‘robotrees’ spared chop after inconclusive report to city council
The 4m high CityTrees on St Patrick's Street and Grand Parade in Cork — dubbed 'robotrees' by critics — were intended to improve air quality. Picture: Larry Cummins
Designed to clear the air but attracting non-stop flak for more than two years, Cork’s controversial ‘robotrees’ have been spared the virtual chop, for the time being at least, after a long-awaited report on their impact on air quality proved inconclusive.
The moss wall, or CityTree devices, which were installed at two city centre locations at a cost to the taxpayer of just over €404,000 as part of a post-covid ‘greening the city’ initiative in summer 2021, will be left in place and plugged in, with annual operating and running costs of almost €18,000, pending more detailed research.
The news was contained in a detailed report to members of the council’s environment, water, and amenity strategic policy committee (SPC) on Tuesday night, prompting new calls for the plug to be pulled on the project.
CityTrees, developed by German-based Green City Solutions, use moss to filter pollutants from the air, and also have a built-in bench.
Critics branded them ‘robotrees’ and a waste of public money, as well as describing them as the most expensive benches in the city, and calling instead for investment in the planting of real trees.
City councillors have been waiting for over a year for data from the devices to assess their impact on air quality. That data was finally presented to the environment SPC on Tuesday night.
Members got a 190-page evaluation report with some 170 pages of data and studies on similar devices in Europe and 20 pages on the context for the purchase and deployment of the machines on Cork’s St Patrick’s Street and Grand Parade.
They were told the council commissioned UCC in June 2022 to undertake a performance study on the machines, at a cost of €2,500.
The report says the UCC study, conducted on eight different rain-free days during June and July 2022, provided “no consistent evidence for improved air quality” either on the CityTree benches or “in the immediate environs” of the machines.
“It should be noted that the measurements were made during a two-month period where air pollution levels were low and small improvements to air quality are difficult to observe,” the report said.
The SPC heard that the council has three options:
- Leave the machines in place;
- Move them elsewhere, either indoors or outdoors;
- Conduct “an extended scientific evaluation project”.
The council said it now wants to find a research partner to do that additional research pending any possible relocation decision.
A former Lord Mayor of Cork, who launched the city’s controversial robotrees over two years ago, led calls on Tuesday night for the plug to be pulled on the embattled project before any more public money is spent on it.
Fianna Fáil councillor Colm Kelleher said the time has come for City Hall to admit they got it wrong on this.
“They were bought for the right reasons but we’re two-and-a-half years into this and we now have a report saying it’s inconclusive that they’ve had any impact on air quality,” he said.
“We are going down a rabbit hole. It’s time to pull the plug.”
Labour councillor John Maher, who previously branded the devices the most expensive benches in the city, said "It’s time to cut the cord on these".
“I don’t think any more research is going to change what we’ve learned already,” he said.
Green Party councillor Oliver Moran also said it is time to call time on the devices.
"I don't think we should have any regrets in trying the moss walls. The enormous environmental challenges ahead of us will require innovation and from time-to-time that will involve taking risks on new ideas.
"If the moss walls don't do much for air quality, they've done lots for encouraging debate on air quality.
"They've raised demands for more real trees to be planted in the city and we're now planting thousands every year.
"I think we should now call time on them. The initial funding was from national sources, we engaged in research on them, but the ongoing costs are too much for the city to continue supporting without evidence of their benefit.
Plant scientist, lecturer, and champion of urban trees, Eoin Lettice, said the longer this saga drags on, the more obvious it is that the robotrees project was a mistake.
“I can wait until the results of the further research come out, and I would be happy if I was proved wrong, but I don’t think that will be the case,” he said.
A principal investigator at the School of Biological, Earth and Environmental Sciences at UCC, Mr Lettice said: “These devices were purchased to do a particular job. They either do that job, or they do not.
“I would question why the city council is now proposing to spend more public money to fund more research to find out if products they purchased from a private company work."
He said it was a pity that the controversy has overshadowed the good work being done by City Hall around the appointment of a trees officer, and the drafting of a tree strategy.
And he said he is not opposed to investment in technical solutions to air pollution but that real trees, green spaces and hedgerows are much more effective, and they deliver many other benefits too including sequestering carbon, and encouraging tourists to spend more time, and more money, in cities with more trees.
The report presented to the SPC on Tuesday is due to be presented to a full council meeting next Monday.
The Local Government Audit Service previously criticised Cork City Council for the lack of any “value-of-money assessment conducted in advance” over the expenditure on the CityTrees project.
It was one of over 500 projects in 11 counties that were funded from a €55m National Transport Authority (NTA) package announced under the July 2021 stimulus plan, in response to the covid crisis.
