Seeking Relief From Heat and Smog, Cities Follow the Wind

Seeking Relief From Heat and Smog, Cities Follow the Wind
Decades ago, the German city of Stuttgart studied local air flow patterns to guide its postwar rebuilding. Now Asia’s megacities are taking lessons to combat smog.

By Matthew Ponsford
July 31, 2025 at 8:42 AM EDT


(Bloomberg CityLab) Take a tram on a hot summer day in Stuttgart and you might hear people grumble about schlechte Luft — or bad air. “Not bad in the sense of evil,” says Indrawan Prabaharyaka, a researcher in urban anthropology at Humboldt University of Berlin. “It’s sticky air — the air is too thick."

The city of two million is built along the Neckar River, in a wide, sink-shaped valley. Residents have long known that the steep hills have a tendency to trap tailpipe emissions and factory fumes, leaving a stagnant fug of pollutants. But topography also provides natural remedies to this smog. Slow-moving natural wind currents weave through the city, drawing cool air by night from meadows and vineyards higher on the hills into the downtown at the base of the valley. Locals call these Luftbahnen (airways), Kaltluftschneisen (cold air corridors), or, most commonly, Frischluftschneisen (fresh air corridors).

If you’re lucky, you might meet a Stuttgarter — often someone older, says Prabaharyaka — who can show you exactly where the air flows around their neighborhood. “People are quite aware of their local microclimate,” says the Jakarta-born ethnographer. Renters in the dense neighborhood of Stuttgart-West often complain about the stillness of their local air, compared to the “thinner” atmosphere in leafy outer suburbs.

The locals’ intimacy with their winds comes off as a curious quirk in Stuttgart, a staid and affluent industrial city that’s home to automakers Mercedes-Benz and Porsche. But according to Prabaharyaka, who has been studying the city’s “aeroroutes” for one of his current projects, this knowledge reflects a unique eight-decade-long experiment in urban climatology. Since the 1950s, Stuttgart has organized its development to maximize natural airflow, preventing construction that would interrupt wind corridors and protecting green areas that allow cooler air to coalesce. ..................(more)

https://www.bloomberg.com/news/features/2025-07-31/from-stuttgart-to-hong-kong-wind-corridors-bring-relief-from-heat?srnd=homepage-americas