Extreme heat has surprised several European cities early in recent weeks. Extreme heat will be a key factor in the performance of players at the Football World Cup, which begins this week in North America. Meanwhile, two environmental dates—Heat Action Day on June 2nd and World Environment Day on June 5th—have converged in a unique initiative that seeks to implement a planned response to extreme heat where changes can have the greatest positive impact: cities.
Under the name “50 Cities at 50°C” or 50@50, the initiative aims to bring together cities from around the world with a common goal: to be better prepared for the extreme heat intensified by climate change, which impacts production, infrastructure, and human health.
“50@50 helps local leaders move faster by sharing practical solutions that protect people, reducing inequality and strengthening urban resilience,” said Inger Andersen, executive director of the United Nations Environment Programme (UNDP), agency that, together with the Paris mayor’s office, is promoting the initiative.
What exactly is the initiative 50@50?
It is a global effort that brings together 50 cities from around the world to strengthen their preparedness for extreme heat. Some of the participating cities are already experiencing temperatures of 50°C, while others estimate they will have to face this in the near future.
What types of actions do these policies include? They varied widely, and their effectiveness depends on each city’s specific conditions, resources and needs.
Some of the most common practices promoted are the installation of water fountains, the expansion of green areas (such as parks, squares, or corridors), and the increase of shaded areas.
50@50 emerged as part of the “Beat the Heat” project, launched at the recent United Nations Climate Change Conference (COP30) to accelerate local action against extreme heat.
Launched on World Environment Day, the initiative aims to build a platform for participating cities to exchange practices and analyze their opportunities and challenges. Effective measures can serve as valuables examples for other cities to consider, implement and adapt according to their owns local contexts.
Among the cities involved, Paris stands out as a model worth following.
Why should other cities look to Paris?
In October 2023, the Paris City Hall conducted what it called a “crisis exercise” in the 13th (Gobelins) and 19th (Danube) arrondissements. “Paris at 50°C” was a full-scale simulation of what the city would be like with temperatures of 50°C and an analysis of which existing measures would be effective, and which would need to be improved, built, or implemented.
Residents, primary and secondary school students, civil society organizations, and key stakeholders such as the local police actively participated to raise awareness about the impact of extreme heat and contribute to a collective assessment of how to improve preparedness. The exercise required more than a year of planification and three months of feedback.
The experience yielded several lessons learned regarding improvements that the city’s crisis management policies needed to implement, especially in providing support to vulnerable people who, due to a lack of necessary infrastructure and/or pre-existing health conditions, are even more exposed to the heat.
The results of the exercise were a valuable contribution to the development of Paris’s Resilience Strategy and its 2024-2030 Climate Action Plan. This is why Paris is now a leading city in the 50@50 initiative, serving as a model for other cities to follow in adapting more effectively.
“Extreme heat is becoming a defining challenge for cities worldwide,” said Emmanuel Grégoire, Mayor of Paris, and emphasized: “Building on Paris’s own 50°C simulation exercise, the 50@50 initiative reflects a strong conviction: cities must act together to anticipate extreme heat and protect their residents.”
Which cities in the Americas are participating?
As of June 1st, 54 cities and local governments have joined the 50@50 initiative.
Barranquilla (Colombia) and Fortaleza (Brazil) will implement high-level engagement actions focused on preparedness and planning. For example, Barranquilla will expand its green spaces, while Fortaleza will implement a heat protocol and a climate risk observatory.
Belo Horizonte and Florianópolis (Brazil), Buenos Aires and Mendoza (Argentina), Santiago de Cali (Colombia), and Santiago (Chile) are some of the Latin American cities that will work at what is classified as a medium level of engagement. This means that their actions will focus on promoting public participation through, for example, guides on how to implement activities effectively.
Other cities in the Americas, such as Rio de Janeiro, will have a “lighter” level of commitment focused on raising awareness and communicating. This includes the creation of communication materials to inform citizens about how to better respond to the heat and what adaptation policies their city offers.
How will the initiative move forward?
The initiative began on Friday, June 5th, to mark World Environment Day, but its development is not limited to that date. Each city will continue the work according to its commitment and on the dates and timeframes they consider most appropriate.
Some participating cities will follow Paris’s lead and conduct their own extreme heat stress tests. This will allow them to obtain an accurate assessment to improve their adaptation policies.
Beyond the 50@50 initiative, any city interested in carrying out the extreme heat simulation exercise can do so. The Paris City Hall has developed a practical manual to help other cities better prepare for a potential 50°C temperature scenario.
