As creators of models, prototypes, and ideas, designers operate in the dynamic space between our current reality and the future we aspire to. Guided by the knowledge from the past and informed by the present, their work shapes the trajectory of our collective journey towards sustainability. Inspired by this vision and in response to the pressing need for climate action, we have opened the call for the UNESCO Creative Cities to participate in the third edition of the Street Design Challenge. Scheduled to run on the months prior to the COP28 in the United Arab Emirates, this initiative invites innovators to challenge the status quo and contribute to the climate change discourse. The theme for this year’s challenge, “Tactical Urbanism to Reduce Heat Islands in Cities,” specifically targets a prevalent environmental phenomenon characterized by higher temperatures in urban areas compared to their surrounding rural landscapes. We firmly believe in the transformative power of design and its potential to foster meaningful changes. By launching this challenge, we aim to amplify the voices of designers in our collective effort against climate change and highlight the pivotal role of design in forging a sustainable future. By collaborating, we can envision and actualize a better future for all. The Street Design Challenge 2023 is an opportunity to foster international exchanges of talent but also to empathize with the reality of our partner design cities around the globe.