Cities around the world are more polluted than ever. According to the World Health Organization, air pollution kills around seven million people each year, and the problem is most pronounced in cities. But what can be done about it? Aside from, for example, focusing on cleaner burning fuels for vehicles (car emissions make up a large portion of urban pollution), are there any quicker solutions?
One might think of planting more trees within city limits. Trees, after all, can eliminate particulates in the air, as well as convert CO2 into breathable oxygen. The trouble is, planting trees within city limits isn't always a viable option. For one thing, the biggest, leafiest trees tend to be the best for cleaning air, but such trees grow slowly and take up a lot of room. Roots are also a major problem. The healthier and older a tree is, the deeper and wider its roots will spread, busting asphalt, bricks, and concrete along the way.
But Brussels-based company Green City Solutions believes it has developed the perfect product to combat urban air pollution. A mobile wall of moss, measuring around 3.5 meters (about 3.8 yards), which they claim can clean as much urban air as 275 trees.
Why moss? According to Zhengliang Wu, co-founder of Green City Solutions, moss is simply better suited to the job. "Moss cultures have a much larger leaf surface area than any other plant. That means we can capture more pollutants."
"Citytree" is an impressive self-watering, self-monitoring, artistically-designed piece of green technology. According to the Green Solutions website, Citytree funtions to both clean and cool urban air. Just like real trees, Citytree "binds particulate matter, nitrogen oxides and CO2e and produces valuable oxygen. At the same time it cools the surrounding air."
Every Citytree comes with integrated technology which "collects, analyses and visualises data about the status and environmental performance of the CityTree." According to Wu, "[there are] pollution sensors inside the installation, which help monitor the local air quality and tell us how efficient the tree is." In other words, the benefits of each individual Citytree are easily measurable.
Citytrees come with automated internal watering tanks which collect rainwater, meaning that the large structures water themselves. For cities interested in installing Citytrees, not having to hire anyone to take on the burden of daily watering is bound to be a bonus.
Citytrees can even be customized, to a degree. They can be ordered with or without an attached bench, and optional protections against vandalism can be installed.