Cities are increasingly exposed to the impacts of climate change: extreme heat, heavy rainfall, and biodiversity loss. Alongside climate mitigation, climate adaptation has thus become a central issue of urban justice. Yet the adaptations required are so demanding in technical, organizational, and financial terms that municipalities can rarely address them on their own. At the same time, planning and construction processes often span decades. This makes swiftly implementable measures all the more urgent—measures that measurably improve urban climate conditions and do more than offer decorative gestures or symbolic activism. Against this backdrop, the project Klimapioniere (literally “climate pioneers”) explores how pragmatic, immediately deployable interventions can be realized in ways that are cost-effective, scalable, largely carbon-neutral, and genuinely effective.