This case study reveals how the Civic IoT project Luftdaten.info, though being organized within limits of technical equipment, resources, and academic knowledge, can contribute in multiple ways to more sustainable cities or communities: (1) People become aware and engaged for their local environment, and some change their behavior, (2) the project itself is managed in a sustainable way, (3) the publicly available data on particulate matter (PM) influences the local public sphere. Explored by a media content analysis and two expert interviews, the PM topic in Stuttgart can be characterized as a discursive long-term process. Nevertheless, a data map comparison shows how easily misunderstandings can occur caused by data analytical and visualization decisions. Finally, this study supports Meadows' idea that "[a]ll people and institutions play their role within the large system structure" but as Luftdaten.info shows, it is not only "industries, governments, environmentalists, and most especially economists [playing] essential roles in contributing to sustainability" it can also be ordinary, tech-savvy people making the first essential steps.