14 Ancient Civilizations That May Have Fallen Because of Climate Change

14 Ancient Civilizations That May Have Fallen Because of Climate Change

Climate shifts have influenced human societies for millennia. In many cases, prolonged droughts, weakened monsoons, volcanic cooling, and other climatic stresses compounded political and economic problems and helped drive migrations, unrest, and societal collapse. Below are fourteen well-studied examples where climate change likely played an important role.

1. Akkadian Empire (c. 2200 BCE)

Evidence from sediment cores and other records points to a multi-century drought in Mesopotamia that reduced river flow and crop yields. Scholars argue that this long dry period undermined agriculture, provoked migrations, and contributed to the empire's collapse.

2. Old Kingdom Egypt (c. 2200 BCE)

Records and paleoclimate data suggest decreased monsoon rains and diminished Nile inundations during the First Intermediate Period. Reduced floodwaters would have cut harvests, fueling famines and political fragmentation.

3. Harappan (Indus Valley) Civilization (by c. 1900 BCE)

Shifts in monsoon patterns and river courses weakened the agricultural base that sustained large urban centers. As water availability declined, populations dispersed from dense cities into smaller, rural settlements.

4. Minoan Civilization (c. 1600 BCE)

The massive eruption of Thera (Santorini) likely triggered short-term climatic cooling and disrupted trade and agriculture. Combined with seismic damage and economic stress, these environmental shocks contributed to Minoan decline.

5. Hittite Empire (c. 14th–12th centuries BCE)

Contemporary texts and climate proxies indicate episodes of drought in Anatolia. Repeated crop failures would have intensified internal tensions and made the state more vulnerable to external pressures.

6. Maya (Classic period, abandoned cities by the 9th century)

Tree rings and other records show sequences of severe droughts across parts of the Maya region. Water shortages, deforestation, and social stress likely combined to prompt urban abandonment and population movement.

7. Ancestral Puebloans (American Southwest, largely abandoned by late 13th century)

Dendrochronology reveals prolonged megadroughts that stressed irrigation and agriculture. Environmental pressure, together with social factors, appears to have driven migrations from cliff dwellings and pueblos.

8. Angkor/Khmer Empire (decline by the 15th century)

Angkor depended on an elaborate system of canals and reservoirs. Evidence of extreme monsoon variability and water-management failures suggests climate instability played a critical role alongside political and military challenges.

9. Tiwanaku (Andean altiplano, c. 300–1000 CE)

Tiwanaku used raised fields and irrigation to support large populations. Paleoclimate data point to prolonged droughts that reduced yields, and efforts to adapt were ultimately insufficient to maintain socio-political cohesion.

10. Norse Greenland (10th–15th centuries)

Colder conditions and changing sea-ice patterns during the onset of the Little Ice Age made farming and grazing marginal. Increased resource scarcity and isolation are linked to the eventual abandonment of Norse settlements.

11. Cahokia (Mississippian center, c. 1050–1350 CE)

Flooding and drought episodes would have disrupted agriculture and water management for Cahokia's dense population. Climatic instability, together with social and political factors, likely contributed to its decline.

12. Zapotec (Oaxaca, decline by c. 900 CE)

Archaeological evidence indicates periods of prolonged drought that reduced water availability and crop yields, prompting shifts in settlement patterns and undermining urban centers.

13. Inca Empire (16th century challenges)

The Little Ice Age brought cooler temperatures and changed precipitation patterns in the Andes. These shifts affected highland agriculture and storage systems, exacerbating internal stresses that made the empire more vulnerable to collapse after European contact.

14. Roman Empire (late antiquity pressures)

Climate variability—fluctuations in temperature and precipitation—altered agricultural productivity in key provinces. These environmental stresses interacted with political, military, and economic crises in contributing to the empire's transformation.

Concluding observations

In these fourteen cases, climate change rarely acted alone. Instead, environmental stress amplified existing vulnerabilities—economic inequality, political instability, warfare, and trade disruptions—and helped tip societies into decline. Studying these past examples highlights the importance of resilience, diversified food systems, and flexible governance when facing climatic uncertainty.