- C40 Co-Chair Mayor Sadiq Khan calls for international investment to protect vulnerable communities from extreme weather, warning that the economic cost of inaction will far outweigh the price of prevention
- Khan challenges all cities across the network and its partners to create early warning systems by the end of 2027
- 95% of cities facing the most extreme heat risks are in the Global South, where communities face significant barriers to accessing climate finance
- At COP31, Mayor Khan urges governments and international financial institutions to invest in protecting lives, livelihoods and economic prosperity
Antalya, Türkiye (11 November 2026) – Mayor of London and C40 Cities Co-Chair Sadiq Khan will today challenge the world’s leading cities and their international partners to close critical gaps in protection against extreme weather by the end of 2027, as he calls for greater investment to safeguard lives, livelihoods and economies from the escalating climate crisis.
Speaking at the UN Secretary-General’s Early Warnings for All event at COP31, Khan will warn that a lack of adequate early warning systems leaves communities more exposed to the dangers of heatwaves, floods, storms and other climate hazards.
He will set a challenge for C40, its member cities and partners to ensure every city in the network has an early warning system by the end of 2027, demonstrating how international cooperation between cities can accelerate practical climate action.
Mayor of London and C40 Cities Co-Chair Sadiq Khan is expected to say: “Climate disaster is no longer the stuff of some distant dystopia.
“It’s killing people, harming communities and impacting our economies right now. And failing to protect ourselves from the perils we face – or prepare ourselves for worse to come – would be a dereliction of duty.”
His intervention comes as cities around the world face mounting human and economic losses from extreme weather. Dangerous temperatures are already disrupting businesses, reducing productivity and making it increasingly difficult for millions of people to work safely. This looks set to be exacerbated in some cities by the unusually strong 2026/27 El Niño.
The burden falls disproportionately on low-income communities and workers who cannot afford to stop earning when conditions become dangerous. Research from the University of Oxford has found that 95% of cities facing the most extreme heat risks are in the Global South.
The economic consequences are substantial. New analysis from London’s City Hall estimates that heatwaves in the British capital this summer resulted in almost £2.5 billion in lost productivity. If similar conditions became the norm, the city’s economy could lose £25 billion over the next decade.
The figures illustrate the financial risks facing cities worldwide, and the growing economic case for investing in protection before disasters strike.
Early warning systems are among the most effective tools available to reduce these risks. By combining weather forecasts, local hazard information, public alerts and emergency preparedness, they allow residents, businesses and emergency services to take action before dangerous conditions develop.
Mayor Khan is expected to warn: “Right now, there are billions of people around the world without basic protections from climate catastrophe, forced to count the cost of a crisis they did not create and do not control.
“That’s why, through C40 cities we’re working to ensure that all our members have early warning systems by the end of 2027. But these systems can never be a substitute for tackling the root causes of the climate crisis.
“Contemplating the sheer scale of the challenge ahead, it can be hard to stay optimistic. But we owe it to the world to hold on to hope. Indeed, rather than sacrificing the planet and its people on the altar of passivity and pessimism, we must follow the example of hope set by our cities – pushing harder than ever towards net zero, even as we adapt to the reality of a warmer world. And we must do so in the belief that a fairer, greener, healthier, and more prosperous future is possible for everyone.”
Cities across the C40 network are already demonstrating how these systems can save lives.
In Ahmedabad, India, the city’s pioneering Heat Action Plan has provided advance warnings and coordinated emergency responses since 2013. Research has estimated that the programme helps prevent approximately 1,190 deaths annually.
In Quezon City, Philippines, the iRISE UP initiative brings together real-time weather monitoring, localised hazard maps and forecasting to help authorities and residents prepare for floods, storms and other threats. By combining live sensor data with historical information, the system supports more effective emergency planning and helps communities understand the risks they face.
Beyond early warnings, cities are investing in measures to make neighbourhoods safer and more resilient. From cooling infrastructure and greener public spaces to improved housing and flood protection, these interventions can reduce disruption, protect vulnerable workers and help local economies withstand increasingly severe weather.
But the scale of the challenge demands greater international support.
Many of the cities facing the most severe climate risks have the fewest resources to respond, despite having contributed least to the emissions driving global warming. Without accessible and predictable climate finance, local governments risk being left to manage increasingly dangerous conditions without the investment needed to protect their communities.
C40 is calling on governments at COP31 to improve cities’ access to climate finance, strengthen cooperation between national and local governments, and ensure that adaptation funding reaches the communities most exposed to extreme weather.
The network’s 2027 challenge will require collaboration between mayors, national governments, international institutions and other partners to strengthen existing systems and address gaps in protection.
Mark Watts, Executive Director of C40 Cities, said: “Extreme weather is already costing lives, destroying livelihoods and damaging economies. Every year that we delay addressing the root causes of climate breakdown and fail to invest in protection, the human and financial costs grow.
“Mayors know what works. Cities like Ahmedabad and Quezon City are showing how early warning systems can give people the information and time they need to prepare for dangerous weather.
“Our ambition is clear: every C40 city should have adequate early warning systems by the end of 2027. This is a challenge to ourselves, our member cities and our partners to turn that ambition into reality.
“But cities cannot do this alone. COP31 must help unlock the finance and international cooperation needed to protect communities, particularly in the Global South. Investing in resilience now will cost far less than paying for the consequences of failing to act.”
With 920 million people living and working in the wider urban areas of C40 member cities, representing approximately 23% of the global economy, protecting cities from extreme heat is fundamental to safeguarding economic prosperity.
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