CityTrees
Large pollution air filtration system / From Wikipedia, the free encyclopedia
CityTrees, also known as Robot Trees, Robo-Trees, and Moss Walls, are large air filters installed in many European cities, as well as Hong Kong, that remove pollutants from the atmosphere.
CityTrees are large structures covered in moss. The filters intend to curb harmful emissions from nearby traffic congestion, including fine dust particles and nitrogen oxides, of which they are claimed to take in 80%,[1] although this has been disputed by some experts.[2]
The structures have been criticised, especially in Cork, Ireland, for their perceived ineffectiveness, possible wastage of energy and water, and costs of around €400,000 per year.[3][4][5] Following this criticism, a Cork City Council debate on the CityTrees scheme was held on 13 November 2023.[6] Councillors decided that the data available for the CityTrees was too inconclusive, partly due to the windy conditions where they were placed, and so they will remain for another 6–12 months.[5]