The steaming hot city of Seville, Spain is turning to an ancient form of architecture to protect citizens from the modern extreme heat brought on by climate change.
With outdoor temperatures approaching 42°C (108°F) in July, making it nearly impossible to walk outdoors, “people scrambled to find shelter in air conditioned homes, offices, and public buildings,” Bloomberg Green reports. But meanwhile, the city was running a pilot project with a qanat, an underground network of piping inspired by infrastructure that dates back to the Persian era a thousand years ago.
The CartujaQanat is “an architectural experiment in cooling solutions that doesn’t rely on burning more planet-warming fossil fuels,” Bloomberg writes. “The system is modeled on ancient tunnels dug to bring water to agricultural fields that were first documented in what is today Iran. The Persians realized 1,000 years ago that the running water also cooled the air in the canals, so they fashioned vertical shafts to bring that air to the surface.”
In Seville, he network of aqueducts uses air, water, and solar power to reduce ambient temperatures by up to 10°C across a site the size of two soccer fields, the news agency adds, citing the city’s public water company Emasesa.
“This is not an air conditioning system like the one you may have in your home,” said Emasesa engineer and project supervisor Juan Luis López. “We use natural techniques and materials to reduce temperatures.”
Bloomberg traces the challenges Seville has faced with its embrace of experimental technologies, including the need for two additional water pumps for the CartujaQanat and a similar project at a local bus station that received no bidders in 2021, after inflation drove down the value of the available funds.
But López said he’s undeterred. “The goal is to test the technology, to learn from it and fine tune it so we can replicate what works elsewhere,” he told Bloomberg.
Located near the southern tip of the Iberian peninsula, the stakes are high for Seville to adapt to the rising temperatures that are a hallmark of the climate crisis, Bloomberg notes. The city saw excess heat kill 103 people over the 12 months ending August 2—although Seville’s heat mortality per 100,000 population is still below Madrid’s and Barcelona’s, “indicating its strategies could be helping to lower the death toll.”
The heat wave also brings economic challenges, jeopardizing Europe’s more important trade route via the parched Rhine River as well as its US$2-trillion tourism industry.