Urban heat is not just a climate story

One fact puts the urban heat crisis into perspective.

Heat kills more people every year than could fit into a sold-out Wembley Stadium – five times over.

That’s twice as many as died in the devastating 2004 Indian Ocean tsunami.

It’s every resident of Miami, Reykjavik or Canberra. Gone. Every year.

There’s no single moment of global shock or natural disaster. Just a silent catastrophe that goes unnoticed by much of the world.

The World Health Organization estimates 489,000 people die from heat each year.

And although that figure is shocking, the UN predicts the death toll will rise as global warming approaches 2.3–2.5°C.

Urban heat is the theme of this edition of Transform, where international experts explore how cities can break heat’s grip with the intelligent use of technology and data.

This is no abstract challenge. Heat reveals systemic failings in city planning, governance, and infrastructure, and causes both productivity and profits to dry up under sustained heat stress.

The heat challenge is solvable – if cities act early, locally, and at scale. But the clock is ticking fast. Cities bear the brunt of the crisis, with the poorest hit hardest, as the urban heat island effect drives local temperatures up to 10°C higher than surrounding rural zones.

The UN recognizes that “we cannot air-condition our way out of the heat crisis.” More cooling can protect people during extreme heat, but if every solution is another compressor on another wall, the result is higher energy demand and higher emissions. The task, therefore, is twofold: expand access to efficient, affordable cooling where it is essential, while redesigning buildings, energy systems, and cities so that staying cool does not make the problem worse.

Comparing urban heat to a “ghost that hits the weakest,” the UN’s first-ever Global Chief Heat Officer Lenio Myrivili told me technologies such as digital twins and early warning systems would be key in tackling it.

“Heat maps and sensors can identify hotspots and help prioritize the most vulnerable groups,” she said. What Myrivili wants is “a different city-making logic that prioritizes climate resilience and heat security.”

That systems-level rethink extends even to infrastructure often seen as part of the problem.

Susanna Kass, an Energy Fellow at Stanford University and an advisor to the UN SDG Program, believes data centers – often portrayed in the press as carbon-emitting monsters – can actually support cleaner, cooler cities. Promising technologies and a new mindset are the key, she says, to driving data center emissions to “Absolute Zero.”

Also in this edition:

• The founder of the Global Cool Cities Alliance says access, not innovation, is the key challenge.
• Quito’s former Chief Resilience Officer explains why tech is an important tool – but citizen participation is essential.
• A venture capitalist investor and entrepreneur predicts climate resilience will be a global investment mega-trend.
• And a Huawei exec paints a future in which agentic AI and high-quality tech enable a world of “autonomous cities” and healthier living.

At COP30, the UN labeled cooling infrastructure essential, alongside water, energy, and sanitation. Technology underpins much of that infrastructure, keeping it affordable, scalable and local.

In the future, ensuring that everyone stays cool will continue to be a matter of life or death for millions worldwide. Whether cities succeed will depend on how quickly technology, data, and policy are aligned around the simple goal of protecting human life in a hotter world.