Sumerians are known as the founders of the urban civilization that dominated in southern Mesopotamia in the 4th and 3rd millennia BC. They developed a network of irrigation channels that made it possible to cultivate cereals in desert areas of the Lower Euphrates, introduced an ideographic script, initially pictographic and then simplified to the form of cuneiform characters impressed in wet clay, built the biggest cities in the world at that time, with monumental temples and enormous palaces.
Despite substantial evidence on the short-term effects of adverse climate shocks, our understanding of their long-term impact is limited. To address such a key issue, research has focused on ancient societies because of their limited economic complexity and their unparalleled experience of environmental and institutional change. Notably, ‘Collapse Archaeology’ literature has reported statistical evidence consistent with the mantra that severe droughts trigger institutional crises. This view, however, has recently been challenged by literature summarized in the paper Climate Change and State Evolution by Giacomo Benati and Carmine Guerriero.