Air pollution is currently one of the biggest threats against humans, and yet it’s highly underestimated in much of the world. According to the World Health Organization, air pollution causes seven million premature deaths per year because of the link between air pollution and health issues like cancer, cardiovascular diseases, and respiratory diseases.
Despite the huge threat air pollution poses, cities continue to expand and hold even more people, making the problem worse while also exposing more humans to the dangerous particulates that circulate in the air. The condensed space that holds so many vehicles and other polluters mixed with the lack of vegetation to soak up the polluted air causes urban spaces to be the worst for human health. In an effort to combat this problem, four friends put their heads together and designed CityTree, which is a mobile structure that can capture as many pollutants as a forest made up of 275 trees.
What makes the “tree” special is that it’s not a regular tree at all; the structure is made up of moss cultures that do the job of absorption much better than any single tree planted in a city could.
“Moss cultures have a much larger surface area than any other plant,” Zhengliang Wu, co-founder of Green City Solutions, explained to CNN. “That means we can capture more pollutants.”
CityTree is able to absorb 250 grams of dust, nitrogen dioxide, and oxygen gases daily; this amounts to 240 metric tons of carbon dioxide every year just from being placed in the right area of a city. The entire “tree” sustains itself using solar panels that generate electricity so that it can collect rainwater, water itself, and run the systems that test how well the tree is working and how healthy the moss is.
“We also have pollution sensors inside the installation, which help monitor the local air quality and tell us how efficient the tree is.” Wu said.
The idea for CityTree first came to mind when three of the co-founders, Dénes Honus, Victor Splittgerber, Liang Wu, met the fourth friend, Peter Sänger, about four years ago, but their interest in environmental solutions to real-world problems started long before that. After the initial three friends graduated from college, they ran workshops at their university about sustainable urban design that focused on new ways to tackle environmental problems in cities. It’s when they met Sänger, who is a graduate in production management for horticulture, that they came up with the idea for CityTree.
About 20 CityTrees are now installed in major cities like Oslo, Paris, Brussels and Hong Kong and they cost $25,000 each, with some of them even coming with built in benches for people’s enjoyment. The biggest problem that the company runs into when installing these structures is bureaucratic obstacles, but they hope to streamline the process with the upcoming installations. The company has also set their sites on installing the structures in developing nations or cities with very low-income because these areas tend to have the worst pollution with no air regulation.
Some have questioned whether these structures really are helping to combat air pollution or if they are simply a pretty structure that means well. Gary Fuller, an expert on air pollution at King’s college, has expressed his doubts at the efficiency of the CityTree.
“Even if you had a perfect air cleaner, getting the ambient air in contact with it is really hard,” he told CNN. “Efforts would be better put into stopping the pollution from forming in the first place, maybe cleaning up a city’s bus fleet.”
In response to this criticism, Green City Solutions, the creator of CityTree, has said that they strategically place each structure so that it can work optimally for the area it inhabits. They are also working on other projects that would help with the efficiency of the CityTree, like a ventilation system to create an airflow that would coincide with the placement of the structure.
It’s impressive that this “tree” has even had so many successful installations already, which is a sign that not only is their invention amazing but that they are smart with business, and this will hopefully propel their future ideas forward.