As climate change has begun to affect our planet more visibly than ever, climate scientists are digging deep into ancient history in order to find evidence of cases of a serious change in the climate.

Stacy Carolin and her team from Oxford University in the U.K. discovered that the Akkadian Empire, which was the first unified Sumerian state, ceased to exist 4,200 years ago due to a severe drought and its effects.

Climatologists have studied the stalactites in the cave of Gol-e-Zard in the North of Iran that developed over the past five thousand years and suggested that the drought and dust storms stripped the Sumerians of all water supplies.

About 4,200 years ago, the stalactites dramatically slowed in growth, which means a sudden reduction in rainfall. The drought lasted more than 300 years. Moreover, the chemical composition of the formations indicates frequent dust storms in the area.

Carolin and her team's study is published in the Proceedings of the National Academy of Science of the U.S.