Cities around the world are being invited to put their hardest climate challenges in front of AI builders, with the winning ideas given a route from hackathon to real-world testing.
What happens when you reverse the usual innovation process?
Instead of starting with a new technology and asking where it might be useful, the 2026 AI x City Climate Action Hackathon is asking innovators to start with something much more fundamental: what does a city actually need?
The global call, launched by the Global Covenant of Mayors for Climate & Energy through its Innovate4Cities initiative, together with the Centre for Human-Inspired AI at the University of Cambridge and the Urban Transitions Mission, is inviting students, researchers, startups, AI builders, climate innovators and multidisciplinary teams to develop AI-assisted solutions to real urban climate challenges.
This year’s priority areas include transportation, informal and marginalised settlements, and climate misinformation and disinformation — from predictive transport systems and electric fleet management to better hazard mapping, equitable service allocation and tools that can strengthen public trust around climate action.
The ambition is bigger than producing an impressive prototype.
From idea to city
The programme follows a three-stage journey: Ideate, Hack and Pilot.
Up to ten finalists will pitch their solutions at the University of Cambridge on 22 September 2026, with the top three teams invited to the Urban Transitions Mission Global Innovation Summit in Viladecans, Spain, in November.
Crucially, selected winners will also have the opportunity to be matched with partner cities for local testing and implementation.
That creates a potentially valuable bridge between the people building new technology and the people dealing with the consequences of climate change every day.
Previous editions suggest the model can work. The 2024 winner, Singapore-based DUCTExplorer, went on to work with Belo Horizonte in Brazil on city-scale heat mapping and heat-mitigation analysis. The 2025 winner, Polisense.AI, used its seed funding to explore applications with cities including Greater Amman, Chisinau and Cordoba.
The bigger experiment
There is a more interesting question underneath the competition: can AI become more useful when cities define the problem first?
That matters because urban climate challenges rarely fit neatly into a single technology category. They involve infrastructure, behaviour, inequality, public trust, policy and local conditions — precisely the kinds of complexities that can be lost when innovation becomes technology-led.
The organisers are therefore positioning the hackathon around responsible, people-centred AI rather than AI for its own sake.
Applications are open globally until 31 August 2026 at 11:59 PM GMT.
For innovators, it is an invitation to do more than build something clever.
Build something a city actually needs.
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