When 26-year-old Peter Sänger and 34-year-old Liang Wu got together, they realized right away that they had something in common. Both firm advocates in the fight against air pollution, they believe that if you can’t measure it, you can’t beat it.
That’s why they founded Green City Solutions: “The solution to quantifiably improve city air.” Their invention the CityTree acts as both an air purifier and a spectacular plant display. Rooted in science, the vertical flat-paneled “trees” dotted around cities across Europe eat air pollution and double up as seats for pedestrians.
Sänger and Wu’s vision is for a world in which people in cities can live healthily. They aspire to create living conditions that allow all people around the world to permanently have cleaner air to breathe.
Nature can help us overcome many human-made environmental problems. Photo by Green City Solutions
Moss naturally filters pollutants from the air very effectively. Using remote technology, the CityTree combines this moss air purifying factor with remote technology to increase the air flow through the “trees”. This allows them to “suck up” and clean more air than normal, and the amount they filter can be increased depending on pollution levels at different times of day.
The German green-tech enterprise is now funded by the European Commission to set up and scientifically test a CityTree network of 15 brand new units in Berlin’s pollution hotspots next year.
Co-founder 34-year-old Liang Wu. Photo by Green City Solutions
UN Environment’s Head of Freshwater, Land and Climate Branch, Tim Christophersen, said that especially in the run-up to the Climate Action Summit 2019—which will focus on climate change and cities, nature-based solutions and resilience to climate change—trees are increasingly recognized as a vital resource.
“Nature can help us overcome many human-made environmental problems, and we need creative solutions. The CityTree can be deployed in air pollution hotspots, as an interesting addition to urban trees and green spaces, which cities should also invest in.”
We spoke with co-founders of the multiple award-winning green-tech company Green City Solutions and inventors of the CityTree, Sänger and Wu, to find out what inspired them on their mission to tackle dirty air and what their plans are for the future.
What inspired you to tackle air pollution, and why do you think this is a problem?
Every day 90 per cent of inhabitants in cities breathe polluted air, causing death and disease. The major components of air pollution are nitrogen oxide, ozone and especially fine dust, or particulate matter, all of which shorten our life span. At the same time, our global population is moving to urban areas in unprecedented numbers.
Co-founder 26-year-old Peter Sänger. Photo by Green City Solutions
How was Green City Solutions started?
Green City Solutions is based on our long-standing friendship. On travels to Asia and southern Europe independently of one another, we experienced the negative consequences of polluted air and the massive build-up of heat in metropolitan regions and began searching for ecological and economic solutions. We founded Green City Solutions in March 2014 with a team of experts in architecture, informatics, engineering and horticulture. Our ambition was and still is to improve air quality in urban environments with a highly efficient and sustainable solution to improve the quality of life for people in cities.
What challenges did you face along the way, and how did you overcome them?
Inventing and introducing a new technology always requires plenty of energy, convincing people and never-ending passion—along with sufficient funding and support from partners and institutions. This can only be successful when you really believe in your solution and when you have a vision that is big and important enough to carry you and your team.
Can you share the positive impacts of the implementation of your project so far?
We have successfully manufactured and sold 50 units of the first generation of our CityTree to cities and companies across Europe. This has been a tremendous success and provided us with many valuable insights and extremely helpful data.
Inventing and introducing a new technology always requires plenty of energy, convincing people and never-ending passion. Photo by Green City Solutions
Where else do you intend to take your invention?
Our CityTrees can already be found in Norway, France, Germany, Belgium, Macedonia and Hong Kong. Our product was also temporarily deployed at many conferences, fairs and events in German cities thanks to its mobile and freestanding design.
How do you measure the impact of the trees—i.e. how much air pollution are they "cleaning"?
Our patented CityTree is a moss filter with integrated ventilation, an irrigation system and sensors to capture environmental data. The moss cultures literally eat particulate matter and nitrogen dioxide out of the air—offsetting many tonnes of CO2 equivalents per year. We measure and test our filter in cooperation with many scientific institutions like the Institute of Air Handling and Refrigeration in Dresden to measure its efficiency.
What is your hope for the future in terms of tackling air pollution?
We have permanently improved and developed our technology further and as of this month our new product generation—now scalable and adaptable—is available. We hope to find the right clients and partners soon to scale up our solution so it becomes a natural component of any given building or infrastructure. Our moss filter can be adapted to any environment. The construction contains sensors collecting environmental and climatic data to regulate and control the unit and ensure that the moss survives. Thanks to our technical innovations and improvements, the new filter generation will require only a few hours of maintenance per year. But it will take more efforts from governments, cities corporations and each one of us to change the situation. Our solution can only be one small piece of the puzzle.
The Young Champions of the Earth regional finalists are out! Winners will be announced in September during the Secretary-General’s Climate Summit. Stay tuned—and why not apply in January 2020? The Young Champions of the Earth Prize is sponsored by Covestro.