From Mayan droughts to Norse abandonments, climate change has influenced the course of civilizations on multiple occasions. Less understood, however, is how such shifts alter daily life—like the roofs above our heads. In China, ancient buildings constructed with wood and earth were tightly coupled to their environment. Bracket sets, or dougong, supported deep eaves that protected against sun and rain. But during the turbulent 3rd–6th centuries, a key architectural element—projecting arms—nearly vanished from records. Scholars have long speculated about artistic or technological reasons. But given the era's intense climate instability, a deeper investigation into environmental drivers was warranted.
A research team from the Chinese Academy of Sciences and the Chinese Academy of Social Sciences has traced an ancient architectural mystery back to climate change. Their study (DOI: 10.1007/s11442-025-2368-6), published in the Journal of Geographical Sciences in June 2025, provides the first quantitative explanation for the sudden decline of projecting arms in Chinese bracket sets during the 3rd–6th centuries. By combining archaeological surveys, paleoclimate reconstructions, and solar radiation simulations, the team uncovers how builders adapted their designs to shifting climate demands—solving a mystery that has puzzled architectural historians for decades.
To decode the architectural enigma, the team examined nearly 250 quasi-architectural artifacts spanning the 1st to 8th centuries, categorizing them into five stages. Their data showed dramatic drops in the presence of projecting arms during two cold and dry phases—220–317 AD and 439–550 AD. These climate downturns, confirmed by multiple paleoclimate records, reduced rainfall and chilled winters, making deep eaves less useful for rain protection and more of a hindrance to winter sunlight.
Using an idealized solar exposure model, the researchers demonstrated that reducing the eave-depth by removing projecting arms could boost sunlight on building walls by up to 35% in winter—enhancing passive heating. The changes were not random: statistical tests showed the timing of architectural shifts closely tracked climate fluctuations. The bracket sets' decline was not about style, but survival—a calculated adaptation to colder, drier conditions. When the climate warmed again, projecting arms returned. These findings not only solve a long-standing puzzle but also to some extent reframe ancient Chinese architecture as a responsive, climate-adaptive system rooted in functional logic.
“This isn't just a story about lost craftsmanship—it's a story of climate resilience,” said Dr. Li Siyang, first author and researcher in climate archaeology, focusing on past human responses. “Our ancestors weren't passive victims of climate—they engineered their way through it. The bracket sets were more than decorative; they were tools of survival, optimized for warmth, light, and protection. By decoding their logic, we gain a deeper understanding of how design can meet environmental demands.”
As climate change intensifies, ancient strategies offer fresh inspiration. The bracket-set redesigns of historic China mirror modern goals of sustainable architecture—adapting form to local climate. Passive heating via solar-oriented design, once born of necessity, now aligns with carbon-neutral ambitions. These historical insights dovetail with China's “Beautiful China Initiative” and its 2060 carbon neutrality pledge. By blending traditional wisdom with modern technology, architects can create climate-responsive buildings that are both efficient and resilient. This study shows that history is not just something we study—but something we can build upon.
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References
DOI
10.1007/s11442-025-2368-6
Original Source URL
https://doi.org/10.1007/s11442-025-2368-6
Funding information
The Postdoctoral Program of the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
About Journal of Geographical Sciences
Journal of Geographical Sciences is an international and multidisciplinary peer-reviewed journal focusing on human-nature relationships. It publishes papers on physical geography, natural resources, environmental sciences, geographic information, remote sensing and cartography. Manuscripts come from different parts of the world.