Back to the Future: Iran's Ancient A/Cs

Today's air conditioners release about 100 million tons of carbon dioxide a year (older models that use hydrofluorocarbons, or HFCs, as cooling agents, are much, much worse). The global air conditioners market size reached a value of $131 billion in 2021 and is forecasted to expand at a CAGR of 6.8% between 2022-2027, as emerging economies develop. Moreover, as global temperatures rise, households will use more of their A/Cs. That's not good for the climate...all the additional carbon dioxides will only contribute to more global warming further increasing the use of A/Cs and so on.

What to do? The solution for the future may be in the past: Iran's badgirs, or windcatchers. Badgirs are one of the engineering marvels Persians developed in the ancient city of Yazd in central Iran--where temperatures reach over 104 Fahrenheit in the summer. Unlike energy-guzzling air-conditioners, they're cost and carbon-free.

The diagram below shows how they work: The rooftop chimney-like structures capture and pull-down fresh air while hotter air rises up and ventilate out through large vertical slots.

It shows scalable sustainable solutions need not to be complex or high-tech. UNESCO listed Yazd as a World Heritage Site in 2017, describing the city as a "living testimony to intelligent use of limited available resources in the desert for survival".