The winner of the Open Innovation Call was announced in Copenhagen during the C40 Mayor’s Summit. The solution by the start-up 4MOSST is seeking to cover surfaces in major cities with moss to reduce urban heating and improve air quality.

With the C40 Mayor’s Summit as a backdrop, Copenhagen has just found its newest and most innovative solution to air pollution and the urban heat island effect. The start-up company 4MOSST aims to tackle several urban climate problems – including urban heat island effect, air pollution and even mental health. Their solution is to create comfortable and aesthetic urban spaces by covering surfaces like walls with moss.

Our solution is systemic as it tackles a range of issues at once with a single solution. Cities are lacking this element of urban greening and this solution is very concretely lifting this challenge

Thimo Hillenius, who is one of the four partners at 4MOSST.

In August, Access Cities partnered with the City of Copenhagen to solve the pressing issues of air pollution and urban heat island effect in Copenhagen. At the event, where 4MOSST was announced, five finalists delivered their final pitch to the judging panel consisting of high level representatives from the City of Copenhagen and prominent Danish companies.

Open Innovation Calls are a part of ensuring liveability in cities

Besides having the finale of the Open Innovation Call, the Access Cities event on Friday focused on solving cities challenges in Copenhagen, Singapore, New York City and Aarhus. City representatives from the four cities engaged in speed dating with the participating companies and organisations.

There are several challenges that cities like Copenhagen and Singapore have in common. Therefore, it has been very relevant for us to get the perspectives from Denmark on these challenges, and experiencing the companies’ innovative solutions. I think many of the solutions are definitely applicable to be scaled throughout South East Asia

Dr. Aravind Muthiah, Strategy Lead of Electric Mobility/Energy Storage Systems at Ecolab.

A similar Open Innovation Call winner was also announced in New York City during the UN Climate Action Week last month. Just as in Copenhagen, the event in New York brought together important leaders from public authorities, companies and organisations from around the world. Both events were focused on gathering international cooperating to find the best sustainable solutions to make cities in the 21st century liveable and fulfil the SDGs.


4MOSST creates an affordable and accessible alternative to existing green walls. The start-up is developing a solution called HSMPaint, an innovative self-growing plaster containing moss spores that after application grows into a moss coverage on walls in cities. The product is a non-toxic paste-like structure, containing moss spores, binding material and moisture protection for the wall. It can be directly applied to outdoor walls out of direct sunlight.

Access Cities  is a Global Alliance for Sustainable Urban Development. During the C40 Mayor’s Summit Access Cities has been broadly involved in the discussions on future sustainable solutions for the world’s cities.

Access Cities is currently running in New York City, Munich, Singapore, and the two Danish cities of Copenhagen and Aarhus, the program aims to solve city problems through multi-stakeholder challenges and open innovation, as a way of accelerating technology and solution knowledge sharing between cities, and to offer better testing opportunities for vendors.