Researchers decode messages on 55,000 oracle bones-typhoon series brought down Bronze Age kingdom.

3,000-year-old animal bones were long dismissed as a religious oddity. Now, with the help of AI, they are revealing a buried climate drama.

On turtle shells and animal bones from China’s early Bronze Age, researchers have identified thousands of puzzling inscriptions. When these texts are linked with modern climate science and artificial intelligence, a striking picture emerges: powerful typhoons and extreme rainfall may have been a decisive factor in the decline of the Shang dynasty - and could have destabilised several other advanced societies of the period as well.

Oracle bones become a climate chronicle of the Shang dynasty

The so-called oracle bones date to the Shang dynasty and are around 3,000 years old. Priests carved questions to the gods into turtle shells or animal bones, heated them over a fire, and interpreted the cracks that formed. What was intended as ritual practice has turned out to be an extraordinarily valuable record of everyday life - especially of weather.

One research group systematically analysed more than 55,000 inscriptions. Certain words appear again and again: rain, heavy rain, flooding, offerings to secure favourable weather. The implication is clear: people were apparently repeatedly exposed to extreme downpours and highly variable conditions.

"The ancient texts paint a picture of a society almost obsessed with rain, floods and storms - and aligning major decisions around them."

This shifts how the era is viewed. Rather than treating power struggles, wars and dynastic change as the only drivers, nature itself comes into focus as a force shaping events.

AI meets archaeology: how Bronze Age climate was reconstructed

To make sense of the bone texts, the researchers combined traditional archaeology with modern data analysis. AI techniques were used to sort the inscriptions, detect patterns and narrow down dates. They then applied physics-based climate simulations of the kind normally used to project contemporary climate change.

Using these models, they reconstructed temperature, air pressure, sea-surface temperatures and wind fields for the period roughly spanning 1850–1350 BC. The outcome points to an interval of intense typhoon activity, reaching far into inland China and triggering extreme rainfall.

• Period 1850–1350 BC: clustering of particularly powerful typhoons
  
• Region: Central China, the Shang dynasty’s core territory
  
• Impacts: floods, crop failures, damage to infrastructure
  
• Evidence base: oracle bone inscriptions + climate models
  

Notably, the spike in references to rain and flooding in the inscriptions aligns with the phases in which simulations show stronger typhoon signatures. In the researchers’ view, coincidence is unlikely.

Typhoons push inland - with devastating consequences

Today, typhoons are usually thought of as coastal events, yet under certain conditions they can travel far inland. That appears to have happened repeatedly in the late second millennium BC. The added water load from heavy rainfall caused rivers to burst their banks, turned fields into waterlogged ground and left settlements uninhabitable.

"Increased typhoon activity threatened survival and cultural development inland," the researchers conclude.

The Central Plains - where Shang rulers built their power base - were particularly exposed. Rivers such as the Yellow River are highly sensitive to rainfall spikes. Even relatively small shifts in precipitation could reshape entire landscapes there.

From questions about rain to a state crisis

The inscriptions show how climate stress could gradually translate into political and social strain. Phrases recur that plead for favourable weather, aim to secure successful harvests, or refer back to earlier floods. The bones suggest that rulers used rain rituals to reinforce their legitimacy - and lost standing when those rituals “did not work”.

If leaders could not protect their population from recurring floods, their authority was soon challenged. In an agriculture-based society, stable yields ultimately amount to state stability.

Population decline and flight to higher ground

The study does not focus solely on the Shang dynasty. Researchers also examined other regions, including the Shu kingdom on the Chengdu Plain in south-west China. A similar pattern appears there, though shifted slightly in time.

For the period between about 850 and 500 BC, archaeological finds indicate population movement. Settlements in low-lying, river-adjacent areas were abandoned, while higher sites expanded. At the same time, climate models again show a phase of heightened typhoon activity and sustained episodes of extreme rainfall.

In the researchers’ assessment, repeated flooding quite literally drove people up the slopes - away from fertile but increasingly dangerous plains.

In the Shang heartland too, archaeological evidence points to a mix of population decline, migration and reorganisation of farmland. Floods do not only ruin harvests; they also damage irrigation systems, storage buildings and transport routes. Each major inundation demanded repairs that tied up resources, while income fell at the same time.

When climate becomes the quiet co-author of history

This new analysis forces historians to rethink the relationship between nature and society in the Bronze Age. For a long time, the fall of the Shang dynasty was explained chiefly through power struggles, internal conflict and military pressure from rising neighbouring states. Those factors mattered - yet the climate evidence indicates that nature was exerting a strong background influence.

A state living under chronic flood risk must allocate resources differently: more embankments, more storage, more emergency reserves. If several harvest years are poor in succession, confidence in leadership erodes and previously loyal groups may turn away. In such moments, even a single external military push can bring down a system already under strain.

Bronze Age climate crisis and today’s climate change

The parallel with the present is obvious, even if the causes differ. While Bronze Age typhoon phases arose from natural variability within the climate system, human activity today is markedly intensifying extreme weather through greenhouse-gas emissions.

Both cases illustrate how vulnerable complex societies are when weather extremes become more frequent. Back then, there were no levees, early-warning systems or globally connected supply chains. Today we have all of these - yet we also have far more people who must be protected and supplied.

• Similarity: extreme rainfall and storms hit densely populated plains especially hard
  
• Difference: causes of climate change (natural vs human-driven)
  
• Lesson: political stability depends heavily on resilience to weather shocks
  

What exactly are oracle bones - and why do they matter to research?

Oracle bones are among China’s earliest known written sources. They record questions addressed to supernatural powers: Will it rain? Will the harvest succeed? Will the king be victorious? Often they include the date, the topic and sometimes the ritual outcome. For historians, they are a unique blend of religious document, administrative note and diary.

For climate research, they offer several advantages:

• High temporal density: many entries per year, often tied to recurring ritual days
  
• Clear subject matter: weather, harvests and flood events are explicitly named
  
• Geographical traceability: findspots are relatively well documented, making regional patterns easier to identify
  

With AI, these huge text corpora can now be deciphered, classified and analysed far more quickly. Patterns that once disappeared in the sheer volume of data now stand out plainly.

Why studies like this are relevant to our future

At first glance, 3,000-year-old bone inscriptions may seem remote from today’s debates about climate policy. Yet that distance is precisely their value: they show how repeated extreme events can tip complex societies off balance - even without modern industry, without megacities and without global financial markets.

The Bronze Age crises underline how tightly agriculture, political order and water management are intertwined. Where fields flood regularly, food security, infrastructure and social stability come under pressure at the same time. That holds for historical kingdoms just as it does for today’s river deltas and coastal metropolises in Asia, Africa or Europe.

Such insights do more than support historical research. They also strengthen the case for long-term planning: resilient infrastructure, retreat options on higher ground, flexible farming systems and early adaptation to increasingly frequent extreme rainfall. In that sense, the message of the oracle bones feels surprisingly modern - except that it once lay in incisions and cracks, rather than in databases and satellite images.