Controversial 'robot trees' removed from Cork City centre

A council spokesperson said that the existing seating around where the trees stood 'will remain and additional planting will be undertaken in both locations'. Picture: Larry Cummins

The so-called 'robot trees' installed in Cork City centre nearly four years ago to help clean pollutants from the air have been removed.

The five devices, which were erected in August 2021 as part of a local authority initiative to provide more greening of the city, were removed from their locations on St Patrick's Street and the Grand Parade early on Sunday morning.

The hexagonal platforms on which they stood remain in place.

The trees, which were created by a German biotech firm called Green City Solutions, had cost taxpayers around €350,000. Their cost was covered as part of a €4m funding allocation from the National Transport Authority (NTA) to Cork City Council.

Designed to filter the air and absorb the toxic pollutant called particulate matter from the air via moss filters, the trees came equipped with in-built sensors used to collate air quality data for analysis.

PM2.5, known as particulate matter, is all solid and liquid particles suspended in air, such as dust, pollen, soot, smoke, and liquid droplets. They also contained 40-inch TV screens used to disseminate information about air quality in Cork City.

In recent months, the trees had begun to show signs of wear and tear.

The so-called robot trees were installed in 2021. Picture: Cork City Council

The devices have been a source of controversy since their installation. 

The same month they were erected, Dean Venables, a researcher at the Centre for Research into Atmospheric Chemistry at University College Cork, labelled them “a costly and ineffectual gimmick”.

In September 2023, UCC emeritus professor of chemistry, John Sodeau, also criticised the robot trees, saying they were waste of funds.

“If I had been asked about the city trees, I would have said ‘don’t bother’," he said at the time.

Prof Sodeau also said that, pending the outcome of a data analysis of the robot trees' effectiveness, he believed the planting of hedging along the street would have been more effective at removing particulates from the air, and it would be better to tackle the root cause of air pollution, rather than trying to clean the air.

"I have looked at these devices in other cities and couldn’t see how they could do what they said on the tin, so to speak," he said.

In November 2023, Cork City council published a report on the data collected from the robot trees which summarised the findings of two studies on their effectiveness. The data was inconclusive.

Just the platforms remain of the robot trees which have been removed from Cork City. Picture: Larry Cummins

Asked why exactly they were removed, a spokesperson for Cork City Council told the Irish Examiner: "The 'City Trees' on St Patrick’s Street and Grand Parade are being removed this weekend". 

The spokesperson said that the existing seating around where the trees stood "will remain and additional planting will be undertaken in both locations".

"Cork City Council will be partnering with the UCC/MTU Joint Cork Centre for Architectural Education (CCAE) to explore a re-purposing of the structures," they added.