Nairobi — June 2, 2026 — More than 50 cities worldwide have committed to confronting one of the deadliest climate risks: extreme heat. The United Nations Environment Programme (UNEP), together with the City of Paris, launched the 50@50 activation on Heat Action Day, ahead of World Environment Day, to strengthen urban resilience against rising temperatures.
Cities including Antalya, Lagos, Melbourne, Mendoza, Paris, and Yangzhou are collaborating to share tested approaches, stress-test systems, and accelerate adaptation measures. The initiative contributes to UNEP’s Beat the Heat drive, introduced at COP30 in Belém, to advance sustainable cooling and protect vulnerable communities.
Practical solutions promoted under 50@50 include cooling islands, expanded green spaces, water fountains, shaded areas, reflective urban design, cycling infrastructure, and early warning systems. UNEP Executive Director Inger Andersen highlighted the urgency: “Extreme heat is already reshaping daily life in cities around the world. 50@50 helps local leaders move faster by sharing practical solutions that protect people, reduce inequality, and strengthen urban resilience.”
Extreme heat is responsible for nearly half a million deaths annually, while driving up energy demand, worsening air pollution, and straining public health systems. Paris Deputy Mayor Emmanuel Grégoire emphasized cooperation: “Cities must act together to anticipate extreme heat and protect their residents. Cooperation is our most powerful tool.”
Over the next year, a dozen cities will conduct extreme heat stress tests with support from UNEP, the C40 Cities Climate Leadership Group, and the City of Paris, which has already carried out a 50°C simulation exercise.
Running through World Environment Day 2026 and beyond, 50@50 builds a global network of cities committed to shifting from coping to redesign, ensuring communities are protected before heat emergencies strike.
