Blockchain brings the transparency and immutability that urban climate projects desperately need. While nature-based solutions are among the most effective tools to reduce urban heat, flooding and carbon emissions, their impact is often estimated rather than precisely measured. By integrating blockchain with Gracity’s sensor data, we enable tamper-proof tracking of KPIs like temperature reduction, carbon sequestration, and water management. This not only builds trust with regulators and investors but also opens the door to new financing models, such as green tokens or impact-linked bonds, making urban adaptation truly investable.