Introducing London's Pollution-Absorbing Bench

London has become the latest city to install a CityTree. Equal parts pedestrian bench, air filter and pollution monitor, the CityTree has been “planted” in Glasshouse Street in the UK capital, just beside the city’s notoriously polluted Piccadilly Circus.

Combining the rapid air filtration properties and space efficiency of plants like lichen and moss with specialised air vents engineered to optimise performance, the CityTree is capable of removing the same amount of pollutants from the air as 275 trees, in only 1% of the same space. London city planners are hopeful the installation can contribute to reducing the capital’s dire pollution issues.

Small tree, big impact

The CityTree was invented in 2014 by German start-up Green City Solutions. It represents the forefront of air filtration in an urban environment, complementing its surroundings while optimising its own performance. Although functional as a bench for tired passers-by, the CityTree has so much more to offer.

The various kinds of moss and lichen used in its creation are very effective at binding harmful toxins such as nitrogen oxides (NOx) and particulate matter 2.5 (PM2.5), while also absorbing a significant amount of carbon from the atmosphere. What’s more, their moisture absorption properties can help to cool the surrounding environs and the solar panels on the top of the CityTree make it a completely sustainable entity. Finally, the cherry on the top of the package is its internet connectivity; with a range of smart-enabled sensors and monitors, the unit is capable of delivering real-time information on the air quality of its surroundings.

The UK already has two CityTrees in Glasgow and another in Newcastle, while there are more than 20 other locations across the globe, including Amsterdam, Berlin, Oslo and Hong Kong.

Cleaning up the Big Smoke

London has long endured a torrid reputation when it comes to air quality; this year, the UK capital exceeded its pollution limits for the year (as specified by the EU) within a single month. One street surpassed the recommended amount within a matter of days. As a result, municipal officials have implemented a number of measures intended to improve air quality and reduce transport-related pollution.

These include bringing forward the introduction of ultra-low emissions zones (ULEZs), which charge diesel vehicles for entering their limits and ban older, more polluting vehicles completely. London Mayor Sadiq Khan has also posited various other ideas, such as phasing out speed bumps in favour of speed ramps, optimising traffic light durations to minimise acceleration and deceleration and converting the city’s bus fleet to hybrid vehicles.

The CityTree represents just the latest in a long line of innovative solutions to the problem of poor air quality and its creators hope that the urban bench is only the tip of the iceberg. “Our ultimate goal is to incorporate technology from the CityTree into existing buildings,” explained Zhengliang Wu, co-founder of the company. “We dream of creating a climate infrastructure, so we can regulate what kind of air and also what kind of temperature we have in a city.”