Air-conditioning can cool a building but it cannot cool a city. As heatwaves become longer and more intense, urban planners are confronting a challenge engineers once barely considered: how do you design an entire city to stay cool?
But climate change is pushing even desert cities beyond the conditions they were originally designed for.
According to the United Nations Environment Programme (UNEP), cities are warming at roughly twice the global average because of rapid urbanisation, while summer temperatures in parts of the GCC could exceed 55 degrees Celsius by the end of the century.
“The principal drivers [of rising temperatures] are attributed to extensive heat-absorbing surfaces, like asphalt, concrete and conventional roofing materials,” says Hani Abdel Razeq, director of sustainability at AESG, a Dubai-based engineering and sustainability consultancy.
Those materials absorb heat throughout the day before slowly releasing it overnight, preventing cities from cooling after sunset. Add limited vegetation, inadequate shade and tightly packed buildings that restrict airflow, and the result is the urban heat-island effect – neighbourhoods that remain significantly hotter than their surroundings.
According to the US Environmental Protection Agency, urban heat islands can make cities up to 7 degrees Celsius warmer than nearby rural areas.
Global consultancy Strategy& notes that the built environment is responsible for approximately 40% of global CO2 emissions. With Gulf countries continuing to build cities at a fast pace, the challenge is no longer simply constructing urban environments, but ensuring they remain comfortable and resilient in a hotter climate.
It isn’t one technology. It’s dozens working together – from street layouts and trees to AI modelling, reflective materials and district cooling – all designed to reduce the amount of heat a city absorbs in the first place.
Start With the Streets
Many of the most effective cooling strategies are surprisingly low tech. Shade remains one of the most powerful tools available. Trees, shaded walkways and narrower streets reduce heat absorption while making outdoor spaces more comfortable.
Long before computer modelling and artificial intelligence, Gulf architecture had already developed ways of coping with extreme heat.
“Traditional Gulf neighbourhoods addressed these problems through narrow sikkas, courtyards, shaded passages and compact development,” says Dr Mohammad Radfar, associate professor in sustainable urban design and planning at the University of Birmingham, Dubai.
“Msheireb Downtown Doha uses some of these principles by incorporating compact blocks, shaded streets, carefully oriented routes, and reduced reliance on cars.”
Cool Entire Districts
Cooling doesn’t stop at street level. Across the Gulf, developers are also cooling entire neighbourhoods rather than individual buildings.
District cooling plants produce chilled water and pipe it underground to multiple buildings, using up to 50% less electricity than conventional air-conditioning, according to Empower, a sustainable cooling solutions provider.