CityTree for Cork - Not seeing the Forest for all of the Trees?

Sometimes, you really have to wonder just what some decision makers are smoking, especially here in Cork. Between road closures that aren’t enforced, pedestrian areas that aren’t worth the paper they’re printed on, unopposed GAA land grabs and infrastructure that is introduced with great fanfare only to be left to crumble, the only conclusion I can make is that the people in city hall have access to some really potent stuff!

The latest outgrowth of this presumed consumption habit is taking place on Patrick Street this week. Three large contraptions that look suspiciously like the result of a one-night stand between a Dalek and an IKEA shelf have just been installed outside the Ulster Bank building there, while two more are slated for installation on Grand Parade. But while these things are most definitely not the result of alien interference, they’re probably about as much use as an umbrella in a hurricane. The objects in question are called “CityTrees” and are designed and built by GreenCity Solutions GmbH, a German start-up. The principle behind them is actually simple and sounds quite compelling on paper. 

This is what all the buzz is about. These things are supposed to be air filters.

These vertical moss beds do most of the hard work of metabolising particulates and cooling the air.

Effectively, the CityTree is a holder for a wall of vertically installed moss. Fans installed in the structure will blow warm ambient air across these moss panels, where the moss’ natural metabolism will absorb CO2, convert it into oxygen via photosynthesis and cool the air via evaporation of some of the water that the moss harbours. This is the basis for the company’s entire product portfolio, which also includes an LCD screen advertising solution called CityBreeze and a modular wall system for buildings, walls, underpasses etc. called AeroCare.  The claims on the company website are pretty impressive: Supposedly, a single CityTree can filter 3500 cubic metres of air per hour, reduce the amount of fine dust pollution in the immediate vicinity by up to 53% and can cool the air in its immediate vicinity by up to 2.5 degrees Celsius. Pretty impressive actually. In theory, that is. All these figures are claims made by the manufacturer. They claim that their work has been double-checked by the Leibniz Institute for Tropospheric Research, however there is nothing about this on their website apart from said claim. A similar claim specifically with regards to the cooling effect of up to 2.5 degrees is similarly unsubstantiated. 

Now there's a buzzword bingo and a half!

With regards to independent research, the situation isn’t really much better, and papers on this topic are about as easy to find as a working public toilet in Cork city centre. Still, thanks to a very informative Twitter thread by John Wenger, a chemistry professor at UCC, I have been able to find two papers. One of these, by Donateo, Rinaldi and collaborators states that during a field test in Modena, Italy, a filtration efficiency of up to 38% was determined, far less than the 53% claimed by GreenCity Solutions but still a pretty decent figure. Said study also found that said filtration efficiency drops like a stone when the the fans are turned off and the system is left to work with passive circulation only, in what should come as no surprise to anyone whose brain consists of more than a solitary cog spinning in the void. As this particular paper is locked away behind a science pay wall, something I despise with the fury of a thousand burning suns, I only have the abstract to go by for this particular study, so I can’t read down into the details. A second study by the same team re-iterates this data. I’ve only gone through it briefly as I want to get this blog post done and dusted in time for my weekly publication day on Wednesday, but the data seems rather compelling, especially since it pertains to an earlier model of CityTree than the CityTree 2.0 that are being installed in Cork. What is also obvious from this research however is that these installations only affect their immediate surroundings and are not suited to contributing to air quality in a city as a whole. In fairness, GreenCity Solutions have shown this in one of the graphics on the CityTree product page on their website. 

It's not as if Green City Solutions hide the fact that their products only have a localised effect. This graphic is taken from their CityTree 2.0 product page.

The CityTree model installed in Cork is significantly newer than the ones tested in Modena, as this graphic from the second paper shows.

This leaves me with a bit of a conundrum. I had originally planned to pour out twelve hundred words of scorn and derision over this contraption. However, while it may not be a solution for the entire city, I can definitely see them providing some welcome relief in the spots where they are installed, especially as the five CityTrees for Cork are deployed in a group of three and a group of two. They also provide something else that is sorely missing throughout the city centre: public seating, at least if you're willing to endure the caterwauling of un-talented buskers. The CityTree installation on Patrick Street is surrounded by wooden benches that will certainly be a welcome relief for many people, and it stands to reason that the two-module installation for Grand Parade will have similar benches. What’s more, they look pretty robust, vastly reducing the chance that a careless city council worker will accidentally on purpose run over one of these things as it happened on Grand Parade a few years back. I’m less sure about the location on Patrick Street, as said spot is a prime lookout for Cork’s bible-thumping pound shop knock-off of the Westboro Baptist Church.

This image shows the biggest culprit for air quality in Cork pretty well. A cluster of CityTrees will not really solve that issue, just provide local, temporary relief.

The benches will be most welcome though... if you can sit there without being accosted by some bible bashers, that is.

Still, there is a pretty strong whiff of gimmickry and tokenism around these things, something that fits well within Cork City Council’s modus operandi in the Ann Doherty era: You invest in something big, modern and shiny, milk it for all the photo opps that you can get, promote the living daylights out of it on social media and make it know to all and sundry that Cork City Council and the chief executive are “doing something” about issue X. Once that is done and said investment has been sucked dry of any last ounce of PR value until there’s nothing left but a shrivelled husk, it is then left to wither on the vine, without even the most basic maintenance or attention. Just look at Coca Cola Zero Bikes, the vast majority of sidewalks and cycle lanes in the city or even the public toilets on Grand Parade if you need any example. I fear that any positive effect that these CityTrees may have will be undone by this tokenistic approach by city management.

Those screens will hopefully raise some awareness about the air quality issues in Cork. And to be honest, I actually like the look of these things.

At the end of this blog post, I feel like the CityTree installation in the city has been unfairly vilified to a certain degree. No, it will not replace any trees that are cut down by ill-informed decision makers in city hall, and no, it will improve the air quality all over the city. Drastic action is still needed both by the city council and by central government in Dublin to massively reduce car traffic in the city, improve public transport, build up a proper active travel infrastructure, and encourage is use. And yes, Cork City Council is failing massively in all of these regards, even with those new cycle lanes, which are just tarmac covered fig leaves in my eyes. However, that is not what these things are designed to do. They are designed to provide local relief in a specific area, to create a small island of relatively fresh air within a certain small radius. This, they do achieve and, in my eyes, they should be given a proper test run in the city. However, city councillors and the executive should be under no illusion that this somehow gets them off the hook. There is a whole lot more work to do, and people will be watching closely!

Oh, and did someone model these things for Cities: Skylines yet?