Megadrought and Collapse in Old Kingdom Egypt (c. 2200-1900 BCE)

What happened?

  • The Old Kingdom, also known as the “Age of the Pyramids,” is a period of ancient Egyptian history spanning from around 2613 to 2181 BCE. This was a particularly dynamic period in which many concepts, practices, and monuments were developed into forms that would influence the rest of ancient Egyptian history. One example includes the view of the king or pharaoh as a living god who ruled absolutely. The famous pyramids of Giza (image below) were also constructed during the Old Kingdom period.

The present-day remains of the Giza pyramid complex in Egypt, constructed over the course of the Old Kingdom (from Liberato, 2006).

  • While the end of the Old Kingdom in Egypt (map below) is not seen by most scholars as an outright “collapse,” it marked a transition to a new social order, and there was a distinct political and cultural shift. Primarily, local magistrates or judges increased their regional power, making and enforcing laws within their reigns, and the priesthood became significantly more powerful, moving the main power in the region away from the pharaohs. This time period was also marked by widespread famine.

Map of the ancient Egyptian empire during the Old Kingdom (from Ross, 2020).

How is this related to climate?

  • Around 2200 to 1900 BCE, an abrupt climate change caused a widespread megadrought (a drought lasting over 10 years) across the Mediterranean, west Asia, the Indus River Valley, and northeast Africa. This megadrought is known as the 4.2-kiloyear BP (4,200 years before present) aridification event and has been attributed to the decline of several civilizations including the Old Kingdom in Egypt, the Akkadian Empire in the Near East, the Liangzhu Empire in China, and the Indus Valley Civilization in South Asia. 
    • Evidence for the presence of a megadrought comes primarily from radiocarbon-dated lakebed sediments and Porites corals, as well as from ice core, tree ring, fossilized pollen, and cave speleothem data. For example, researchers measured oxygen isotope concentrations in lake sediments and cave stalagmites to recreate temperature and precipitation records. The lower abundance of pollen from wetland plants and higher concentrations of charcoal created by fires are also used as evidence for drought conditions.
    • Climate scientists have proposed several different explanations for the cause of this aridification event. One proposal is that climate change was caused by the North Atlantic Oscillation (NAO), which is an atmospheric circulation pattern over the North Atlantic Ocean. The alternating “positive” and “negative” phases of the NAO (image below) change the direction and intensity of the cyclonic North Atlantic westerlies, which are the winds blowing to the east across the ocean, from North America towards Europe. 
      • During the negative phase of the NAO, air currents shift further northwards due to a low atmospheric pressure difference. In the positive NAO phase, the atmospheric pressure difference is strong, and the air currents travel straight across the North Atlantic Ocean (image below). 
    • This atmospheric disturbance – the switch from negative into positive NOA mode caused diminished precipitation in northeast Africa as its climate changed from warm and wet to cool and dry (image below). As a result, precipitation decreased by 30-50% in this region, temperatures dropped slightly, and dust storms became frequent.

Image of the North Atlantic Oscillation (NAO), an atmospheric circulation system in the North Atlantic Ocean. During the negative phase of the NAO (pictured on the left), moisture is pushed north in the Atlantic, bringing warm and wet conditions to the Mediterranean and Egypt. During the positive phase, the jet stream travels straight across the Atlantic to northern Europe, causing cool and dry conditions in Egypt (from Lindsey and Dahlman, 2009).

  • The megadrought completely desiccated the agricultural regions of the Mediterranean, especially in areas where irrigation was not used for dry-farming or crop production during dry seasons. This climate change also reduced the amount of water in the Nile River which flowed through the Old Kingdom (map above), causing irrigation failure and thus, a sharp decrease in agriculture yields and extreme food shortages.
    • Ancient Egyptian agriculture was overwhelmingly tied to the Nile River, so although the megadrought was not entirely responsible for the collapse, the greatly reduced Nile flow decreased agricultural yield, creating widespread famines which certainly played a large role in the instability and discord of this period.
  • The beginning of the megadrought coincided with the wane of Old Kingdom Egypt and the beginning of the First Intermediate Period (image below), a period between the Old and New Kingdoms marked by transition and characterized by a decrease in the power of the central government in Memphis, the capital city, and an increase of in the power of provincial administrators in separate regions.

Timeline of the different time periods of ancient Egypt from 3000 BCE to 1 CE (from van der Crabben, 2020).

References and additional resources

How to cite this page

Megadrought and Collapse in Old Kingdom Egypt (c. 2200-1900 BCE). (2025, February 7). Climate in Global Cultures and Histories: Promoting Climate Literacy Across Disciplines. Retrieved Month Date, Year, from https://www.science.smith.edu/climatelit/megadrought-and-collapse-in-old-kingdom-egypt-c-2200-1900-bce/.