Is it a living lab, smart city, an urban meteorological network or an urban observatory? No, it is an urban data demonstrator.

Underpinned by a ‘low-cost’ sensing revolution, scientists and decision makers now have access to an unprecedented range of ‘live’ data streams covering a range of urban environmental phenomena.  From air quality to flood risk to climate change adaptation, weather data underpins much of this capacity to monitor urban environmental hazards with the urban climate community long pioneering efforts in the space.  As a fusion of smart city and urban meteorological network concepts, the urban observatory approach is now increasingly common.  By combining numerous data streams, it is possible to generate insights into how a city responds in real time to environmental stimuli (such as the weather).  Importantly, it also paves the way for the development of urban digital twins, using hyperlocal data to inform (and automate) decision making in real-time – at least in theory.   The problem is that whilst the art-of-the-possible can be showcased using digital shadows, examples of true urban digital twins don’t really exist.  Even if they did, they would be fragile, relying on ephemeral data often funded by academic institutions or reliant on transient opportunistic sensing datasets to achieve longer-term aims.  This also hinders our ability to monitor long-term local change which is so crucial as our metropolitan areas scramble to adapt to the changing climate.   There lies the challenge.  We will need our future monitoring networks to be able to serve two quite different purposes, generating both hyperlocal real-time data for digital twins whilst also providing the more traditional ‘offline’ dataset needed for long-term monitoring.  With little, or zero, standardisation for real time datasets, and every city currently doing their own thing, the community needs to act to force the transition from urban data demonstrators to something more durable.