A dashboard that visualizes the amount of CO₂ reduction generated through reuse activities.

Green Signal is a time-based display that shows the amount of CO₂ reduction generated through individual reuse actions, such as swapping or purchasing secondhand items.

At the Mercari Green Friday Project 2025: Reuse Fashion Park, clothing reused by visitors is transformed digitally into “threads.” The colors and materials of those garments become visual strands that weave together to form the passing time.

Issue

How does a person’s sense of impact change when they take part in reuse actions?

Green Signal aims to create a chain reaction in which people who engage in reuse feel positive emotions and naturally move toward better choices.

Rather than simply presenting numerical data, the project visualizes the sense that one’s actions truly matter. Through creative expression, it makes the impact of individual behavior tangible and rewarding. In doing so, it explores a new form of experiential design that turns environmental contribution into a felt experience.

Creation

Digital threads woven by reuse actions.

Clothing reused by visitors is converted in real time into digital “threads” based on each item’s color and material. As these threads gradually fill the screen, individual actions become a signal that connects to a better future.

At the top of every hour, a time signal announces the CO₂ reduction generated during the previous hour. Voices saying “thank you” in multiple languages from around the world layer together, creating a collective expression of appreciation.

The sound design also reflects the positive environmental impact of reuse. It blends natural elements—such as birdsong and the sound of wind through forests—to evoke harmony with nature. This acoustic design balances auditory comfort with a forward-looking message.

The calculation of CO₂ reduction follows the “Positive Impact (GHG Reduction Contribution)” methodology developed by the research and development network Mercari R4D Lab at Mercari, Inc..