The Washington PostDemocracy Dies in Darkness

Drought may have doomed this ancient empire — a warning for today’s climate crisis

Hattusha, located near modern Bogazkale, Turkey, was the capital of the Hittite Empire during part of the Bronze Age. (Izzet Keribar/Getty Images)
6 min

No one knows for sure what happened to the ancient Hittite Empire. For nearly 500 years, its dominion extended across much of modern Turkey and into Syria and Lebanon. Its kings dwelled in massive stone palaces inside a gated capital city. Large-scale farming, sophisticated irrigation systems and far-reaching trade networks filled the imperial coffers.

And then, just after 1200 B.C., it vanished. Archaeological investigations suggest that the royal administration packed up the palace and fled the capital. The city was abandoned and later burned. Few accounts from the fractured kingdom remain to explain exactly why.

But climate data, captured in the rings of long-dead trees, offer a clue. A new analysis published Wednesday in the journal Nature shows that the Hittites endured three consecutive years of extreme drought right around the time that the empire fell. Such severe water shortages may have doomed the massive farms at the heart of the Hittite economy, leading to famine, economic turmoil and ultimately political upheaval, researchers say.

“One year of drought is a problem. Two years — it’s a crisis. By three years in a row, perhaps it’s actually more than a crisis,” said Sturt Manning, an archaeologist at Cornell University and lead author of the Nature study. “Seeing that back-to-back-to-back failure — that’s probably what overthrows a major state.”

The study is the latest from an accumulating field of research linking the fall of civilizations to abrupt shifts in Earth’s climate. In the ruins of ancient Egypt, Stone Age China, the Roman Empire, Indigenous American cities and countless other locations, experts have uncovered evidence of how floods, droughts and famines can alter the course of human history, pushing societies to die out or transform.

As human greenhouse gas emissions, mostly from burning fossil fuels, warm the atmosphere and alter the lands that modern nations were built on, archaeologists say this research offers both a warning and a reassurance. It underscores the peril of increasingly frequent and severe climate disasters. But it also points to strategies that might make communities more resilient: cultivating diverse economies, minimizing environmental impacts, developing cities in more sustainable ways.

To Müge Durusu-Tanrıöver, an archaeologist at Temple University who was not involved in the newly published research, the lessons of history are especially relevant after two massive earthquakes ripped through southern Turkey and Syria this week, killing more than 11,000 people and leaving thousands more stranded in the cold.

Though not climate-related, the quakes provide yet another reminder of the Earth’s power to upend societies — and of the need for measures to protect vulnerable people from environmental harms.

“Things like climate change, earthquakes, drought — they are of course realities of our lives,” Durusu-Tanrıöver said. “But there are human actions that can be taken to foresee what will happen and behave accordingly.”

To figure out what happened to the Hittites, Manning and his colleagues turned to millennia-old timbers found inside a gigantic tomb in central Turkey. The wood came from juniper trees that had been still standing when the Hittite Empire fell. Junipers are an especially long-lived species, which meant the growth rings within their trunks would contain a record of the weather throughout their life spans.

In the half-century leading up to empire’s collapse, the scientists found, the rings inside the tree trunks gradually start to get narrower — suggesting that water shortages were limiting the junipers’ growth. Chemical analyses of the kind of carbon captured in the wood also showed how drought altered the trees at the cellular level.

These results jibe with inscriptions on cuneiform tablets from that time in which Hittite officials fretted over rising food prices and asked for grain to be sent to their cities. But Manning said the empire — which was known for its elaborate water infrastructure projects and massive grain silos in major cities — should have been able to survive this “low frequency” drought.

Then, between 1198 and 1196 B.C., the region was struck by three of the driest years in the entire 1,000-year-long tree ring record. The abrupt spurt of intensely dry weather may have been more than the Hittites could bear. Within a generation, the empire had dissolved.

“We can’t prove that’s connected, but it seems to be a remarkable coincidence,” Manning said. “Very few societies ever plan for more than one or two disasters happening consecutively.”

The conclusion that climate change played a role in the Hittites’ demise seems obvious to Yale University archaeologist Harvey Weiss. In his book “Megadrought and Collapse,” Weiss explores how a global shift in rainfall patterns 4,200 years ago helped end political regimes from India to the Middle East. He argues that history has been shaped by abrupt climate “shocks” that fragmented societies or forced people to migrate.

“But I think it’s naive to believe that three years of drought would bring down the storerooms of the Hittite Empire,” Weiss said. He argues that the longer-term drying trend, which has been documented in other studies, was probably more significant.

The Hittites were not the only Bronze Age superpower to disintegrate around this time. In what is now Greece, the great cities of the Mycenaean civilization were abandoned or destroyed. Some states, such as Egypt’s New Kingdom, endured in a weakened form.

And in other cases, new cultures blossomed as people shifted their survival strategies or migrated to more welcoming environments.

“What’s a crisis for some becomes almost an opportunity for others,” Manning said. “You have adaptation and resilience in the form of new states and new economies emerging.”

Why were the Hittites unable to cope with their shifting environmental conditions? Durusu-Tanrıöver blames an unsustainable economy and centralized political system. The intensive agricultural practices required to support the capital city probably exhausted the region’s water resources and weakened surrounding ecosystems, she said.

She sees parallels to modern urban areas, which are both major sources of planet-warming pollution and especially vulnerable to climate change impacts like extreme heat.

“There is always something to be learned from the past,” she said. “Unfortunately, those are lessons we keep not learning.”

More on climate change

Understanding our climate: Global warming is a real phenomenon, and weather disasters are undeniably linked to it. As temperatures rise, heat waves are more often sweeping the globe — and parts of the world are becoming too hot to survive.

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Inventive solutions: Some people have built off-the-grid homes from trash to stand up to a changing climate. As seas rise, others are exploring how to harness marine energy.

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