A smart tool beating urban heat with actionable insight

This article is based on an Ignite Stage presentation at the 2025 Global Platform for Disaster Risk Reduction. The Ignite Stage offers fast-paced, impactful talks from diverse voices working at the forefront of disaster risk reduction.

It's 2 am in Freetown, Sierra Leone.Aminata fans her baby in the sweltering heat in the middle of another blackout, praying each shallow breath isn't his last.

Thousands of kilometres away, in Bengaluru, India, Meena, a waste picker, sorts through mounds of plastic in the predawn heat, her hands blistered, her body aching after another sleepless night. She's never felt a hot season like this.

In São Paulo, Brazil, Marco's concrete apartment traps the heat as his son tosses in the dark, the broken AC a silent reminder of what they can't afford.

Three people. Three cities. Different languages. Different lives. But one shared reality: the invisible threat of urban heat.

Extreme heat is neither rare nor fair

Heatwaves are longer, deadlier, and the impacts are deeply unfair, because the poorest parts of our cities are almost always the least protected. The urban heat island effect is causing cities to warm at twice the global average rate, creating new health challenges and an increase in heat-related deaths.

Every year nearly half a million people die as a direct result of extreme heat , and as temperature rise, this figure is set to increase by an additional 50% by 2050. Economic productivy will suffer: some 2.41 billion workers - 70 per cent of the world's working population - are exposed to excessive heat.

Extreme heat affects the social, ecological and economic fabric of cities worldwide. The problem demands action to prevent, mitigate and manage extreme heat risk in the short, medium and long term.

What to do with all the data

Earth Intelligence means we have access to more data than ever before.

Yet, while we know more than ever, we're not doing enough collectively. Not because we don't care, but because data is often fragmented, inaccessible or not detailed enough to inform action at the local level.

Cities need neighbourhood-level intelligence, not global averages. They need to know where heat will hit hardest, who is most at risk and what to do about it.

A global, collaborative effort

That's where the Global Heat Resilience Service comes in. This is a joint effort from the Group on Earth Observations and the C40 Cities, the Global Covenant of Mayors and IBM, with support and inputs from the World Meteorological Organization (WMO), the Global Climate Observing System, the United Nations Office for Disaster Risk Reduction (UNDRR) and a range of other strategic and knowledge partners.

Responding to the UN Secretary-General's Call to Action on Extreme Heat and the UN's Early Warnings for All (EW4All) initiative, the Global Heat Resilience Service will also align with a forthcoming common framework for extreme heat risk governance, which is being developed by national and international experts coordinated by UNDRR, the Global Heat Health Information Network (GHHIN) and WMO.

Group on Earth Observations (GEO) Secretariat

Intuitive and engaging tools for cities

The Global Heat Resilience Service isn't a top-down tool. It's co-designed with cities, grounded in real needs and built to serve local decision-making.

We're working with cities like São Paulo, Freetown and Bengaluru to map out user journeys, identify data gaps and build trust - to make this service is helpful to those who need it.

City officials have told us they need intuitive and engaging tools for decision-makers across sectors and domains, especially mayors, that help link multi-sectoral climate data directly to practical actions.

They highlight challenges like fragmented data, lack of community engagement and the urgent need to identify vulnerable populations and heat-prone areas for targeted interventions.

The message is clear: cities need reliable, accessible and action-oriented intelligence to guide immediate and long-term planning.

Smart technology and citizen science for actionable risk information

The Global Heat Resilience Service will combine Earth observation data, AI, ground sensors, and citizen science to generate insights that cities can use.

Like heat forecasts, and. risk maps with vulnerability overlays by income, age, and health. Suggested interventions - from tree planting to reflective surfaces. This is about more than technology. It's about creating a shared language and opportunities for action, recognising the interconnected and interdependent nature of extreme heat risk.

The aim? By 2030, the Global Heat Resilience Service will deliver actionable heat risk intelligence to every urban area worldwide.

You can play your part!

But we can't do it alone. If you're reading this and you're involved in urban planning, public health, infrastructure, energy, transportation, insurance, investment or any other sector thinking about the impact of the shifting climate, this touches your work.

Join us. Partner with us. Help us scale a solution.

Because extreme heat is no longer a future problem, it's here, now, along with our capacity to respond.

Find out more about the Global Heat Resilience Service.

This blog is based on a presentation made on the Ignite Stage at the 8th Session of the Global Platform for Disaster Risk Reduction.

Watch the recording.

Martyn Clark is Urban Resilience Coordinator for the Group on Earth Observations Secretariat, where he leads on urban-themed activities in the GEO Work programme. He draws on his working knowledge of the challenges and opportunities urban policymakers face in managing sustainable and resilient urbanisation, and his understanding of how earth observation can be used fill critical evidence gaps, particularly in low and middle-income countries.

Martyn has 20 years' experience in the public and private sector, having worked with a range of development organisations, as well as national, sub-national and municipal governments. He has a decade's experience working on urban development programs in Africa and Asia, much of which has focused on developing low-cost, replicable tools and approaches to promoting sustainable urbanization. Martyn has extensive experience in providing technical assistance around the use of Geographic Information Systems and Remote Sensing, and in-situ data collection and surveys in urban contexts.