Athens
Athens, the capital of Greece, is home to nearly 650,000 residents and forms the core of the larger Athens metropolitan area in the Attica region.
As one of Europe’s oldest cities, Athens faces unique urban challenges linked to density, heat stress, and limited green space. Only about 12% of the city’s land is classified as greenspace, yet significant efforts are underway to expand and improve access to nature. Key areas such as the National Garden, Lycabettus Hill, and neighbourhood pocket parks provide vital ecological and recreational functions.
The city’s Resilience Strategy and Climate Action Plan include a strong focus on urban greening and community-driven adaptation. Current priorities include planting more street trees, revitalising small parks, and involving local groups in shaping greener public spaces that respond to everyday needs.
Combining citizen monitoring and urban data to tackle heat stress.
Athens is combining digital tools and citizen participation to tackle heat stress and improve tree management across the city. Residents, including municipal outdoor cleaning workers, are equipped with wearable temperature and relative humidity (TRH) sensors connected to the EcoPulse mobile app to measure temperature, humidity, and moments of thermal discomfort during their daily routines.
This data reveals where urban heat is most intense and informs policies such as the Climate Adaptation Strategy and Climate City Contract. In parallel, teachers, students, and neighbourhood residents use a custom-built Tree Registry mobile app to identify and map local street trees, documenting species, condition, and location to verify and improve the city’s tree database. Additionally, Athens has installed around 20 low-cost air quality sensors on municipal buildings to monitor PM2.5 concentrations as part of a broader citywide network.
Data from all three initiatives are shared with municipal departments and integrated into urban maintenance and planning workflows. By embedding structured data collection into everyday activities such as walks and school projects, Athens directly engages citizens in local greening actions and climate adaptation.
Themes
Air
Quality
Air
Quality
Greenspace
Perception
Sensors / Technology / Data
Mobile
Applications
Air Quality
Monitors PM2.5
Wearable
Sensors
Discover Athens approach
Pop Up Community and Culture Labs
Urban ReLeaf Pop-Up Labs are short-term creative initiatives that transform citizen-generated environmental data into accessible community and cultural experiences, connecting science, creativity and local knowledge to make climate challenges visible and meaningful.
In Athens, the Pop-Up Lab focuses on the urban environment of Athens including heat stress, urban green and air quality. DAEM is commissioning a comic artist to create accessible, engaging storylines for the environment of the city and the citizens’ contribution for a sustainable city. Creative storytelling from the comics and the participatory engagement of the Athens pilot aim to support environmental awareness, dialogue, and empower younger audiences to understand and respond to the environmental challenges in their city.
