The Quality Urban Label and the 4Q City Model: Levers for Urban Adaptation and Climate Change Mitigation in Mediterranean Cities

Simple indicators are often used to summarize the complexity of systems or products, commonly through color-coded labels paired with letters. These labels, like those indicating energy efficiency or nutritional ratings, help users quickly understand essential characteristics. Building on this approach, the Quality Urban Label (QUL) has been developed to assess public space adaptation to urban climate change. The QUL utilizes four key indicators, called quality components: air quality (pollutants), noise pollution, thermal comfort, and visual comfort. It ranges from 0 to 25 and is represented by a color and letter code (green, A, ranging from 0 to 2; blue, B, ranging from 6 to 11; orange, C, ranging from 15 to 19; and red, D, ranging from 22 to 25), with green representing better quality and red poorer quality. The QUL aims to evaluate public spaces based on energy consumption reduction, greenhouse gas emissions reduction, and progress toward carbon neutrality. This article explores some ecological and climate benefits of the QUL, especially in warm Mediterranean cities. An objective label that quantifies the alignment of urban public space with climate neutrality has numerous advantages, which are discussed in the article. In addition, it is a key tool for urban project planning, focused on reducing urban social inequalities and promoting a just energy transition of urban public space.