Collapse: Climate change

Ten Civilizations or Nations That Collapsed From Drought
By: Jeff Masters edited for brevity from wunderground . The original article can be read in PDF format below, great photos, good links for references.

Drought is the great enemy of human civilization. Drought deprives us of the two things necessary to sustain life–food and water. When the rains stop and the soil dries up, cities die and civilizations collapse, as people abandon lands no longer able to supply them with the food and water they need to live.

Collapse 1. The Akkadian Empire in Syria, 2334 BC – 2193 BC. In Mesopotamia 4200 years ago, In “Climate change and the collapse of the Akkadian empire: Evidence from the deep sea”, a team of researchers studied deposits of dust in the Gulf of Oman. A large increase in dust 4200 years ago coincided with a 100-year drought that killed 30% of the population in Syria. The drought, called the 4.2 kiloyear event, is thought to have been caused by cooler sea surface temperatures in the North Atlantic. The paper concluded, “Geochemical correlation of volcanic ash shards between the archeological site and marine sediment record establishes a direct temporal link between Mesopotamian aridification and social collapse, implicating a sudden shift to more arid conditions as a key factor contributing to the collapse of the Akkadian empire.”

Collapse 2. The Old Kingdom of ancient Egypt, 4200 years ago. The same drought that brought down the Akkadian empire in Syria severely shrank the normal floods on the Nile River in ancient Egypt. Without regular floods to fertilize the fields, poor harvests led to reduced tax income and insufficient funds to finance the pharaoh’s government, hastening the collapse of Egypt‘s pyramid-building Old Kingdom. An inscription on the tomb of Ankhtifi during the collapse describes the pitiful state of the country when famine stalked the land: “the whole country has become like locusts going in search of food…”

Collapse 3. Around 1200 BC, Eastern Mediterranean civilizations declined or collapsed. According to a 2013 study studying grains of fossilized pollen shows that this collapse coincided with the onset of a 300-year drought event. This climate shift caused crop failures and famine, which “precipitated or hastened socio-economic crises and forced regional human migrations in the Eastern Mediterranean and southwest Asia.” The fall of Troy (complete with the famed Trojan Horse), an event recounted in Greek mythology at the end of the Bronze Age, typifies the fall.

Collapse 4. The Maya civilization of 250 – 900 AD in Mexico. Severe drought killed millions of Maya people due to famine and lack of water, and initiated a cascade of internal collapses that destroyed their civilization at the peak of their cultural development, between 750 – 900 AD. Haug, G.H. et al., in their 2003 paper in Science, “Climate and the collapse of Maya civilization,” documented substantial multi-year droughts coinciding with the collapse of the Maya civilization. Xunantunich.

Collapse 5. The Tang Dynasty in China, 700 – 907 AD. At the same time as the Mayan collapse, China was also experiencing the collapse of its ruling empire, the Tang Dynasty. Dynastic changes in China often occurred because of popular uprisings during crop failure and famine associated with drought. Sediments from Lake Huguang Maar in China dated to the time of the collapse of the Tang Dynasty indicate a sudden and sustained decline in summertime monsoon rainfall. Agriculture in China depends upon the summer monsoon, which supplies about 70% of the year’s rain in just a few months.

Collapse 6. The Tiwanaku Empire of Bolivia’s Lake Titicaca region, 300 – 1000 AD. The Tiwanaku Empire was one of the most important South American civilizations prior to the Inca Empire. After dominating the region for 500 years, the Tiwanaku Empire ended abruptly between 1000 – 1100 AD, following a drying of the region, as measured by ice accumulation in the Quelccaya Ice Cap, Peru. Sediment cores from nearby Lake Titicaca document a 10-meter drop in lake level at this time. Tiwanaku site in Tiahuanaco, Bolivia.

Collapse 7. The Ancestral Puebloan (Anasazi) culture in the Southwest U.S. in the 11th – 12th centuries AD. Beginning in 1150 AD, North America experienced a 300-year drought called the Great Drought. This drought has often been cited as a primary cause of the collapse of the ancestral Puebloan (formally called Anasazi) civilization in the Southwest U.S., and abandonment of places like the Cliff Palace at Mesa Verde National Park in Colorado. The Mississippian culture, a mound-building Native American civilization that flourished in what is now the Midwestern, Eastern, and Southeastern United States, also collapsed at this time. Cliff Palace

Collapse 8. The Khmer Empire based in Angkor, Cambodia, 802 – 1431 AD. ruled Southeast Asia for over 600 years, but was done in by a series of intense decades-long droughts interspersed with intense monsoons in the fourteenth and fifteenth centuries that, in combination with other factors, contributed to the empire’s demise. The climatic evidence comes from a seven-and-a-half century reconstruction from tropical southern Vietnamese tree rings in “Climate as a contributing factor in the demise of Angkor, Cambodia”.

Collapse 9. The Ming Dynasty in China, 1368 – 1644 AD. China’s Ming Dynasty–one of the greatest eras of orderly government and social stability in human history–collapsed at a time when the most severe drought in the region in over 4000 years was occurring, according to sediments from Lake Huguang Maar. A weakened summer monsoon driven by warm El Niño conditions in the Eastern Pacific was responsible for the intense drought, which led to widespread famine. An inscription found carved on a wall of Dayu Cave in the Qinling Mountains of Central China dated July 10, 1596, during the 24th year of the MIng Dynasty’s Emperor Wanli, said: Mountains are crying due to drought.”

Collapse 10. Modern Syria. Syria’s devastating civil war that began in March 2011 has killed over 300,000 people, displaced at least 7.6 million, and created an additional 4.2 million refugees. While the causes of the war are complex, a key contributing factor was the nation’s devastating drought that began in 1998. The drought brought Syria’s most severe set of crop failures in recorded history, which forced millions of people to migrate from rural areas into cities, where conflict erupted. This drought was almost Syria’s worst in the past 900 years (89% chance), according to a 2016 tree ring study.

Wunderground’s climate change blogger, Dr. Ricky Rood, has his take on the current drought in Syria in his March 21 post,

Jeff Masters References for original article

Buckley, B.M. et al., 2010, “Climate as a contributing factor in the demise of Angkor, Cambodia,” Proc. Natl. Acad. Sci. U.S.A. 107, 6748–6752 (2010).

Cook, B.I. et al., 2016, “Spatiotemporal drought variability in the Mediterranean over the last 900 years,” JGR Atmospheres, DOI: 10.1002/2015JD023929

Cullen, H.M., and P.B. deMenocal, 2000, North Atlantic Influence on TIgris-Euphrates Streamflow, International Journal of Climatology, 20: 853-863.

Cullen et al., 2000, “Climate change and the collapse of the Akkadian empire: Evidence from the deep sea,” Geology 28, 379 (2000).

deMenocal, P.B., 2001, “Cultural responses to climate change during the late Holocene,” Science 292, 667–673 (2001).

Gleick, P., 2014, Water, Drought, Climate Change, and Conflict in Syria, Weather, Climate, and Society, published online 1 July 2014, DOI:

Haug, G.H. et al., 2003, “Climate and the collapse of Maya civilization,” Science 299, 1731–1735 (2003).

Hoerling, Martin, Jon Eischeid, Judith Perlwitz, Xiaowei Quan, Tao Zhang, Philip Pegion, 2012, On the Increased Frequency of Mediterranean Drought, J. Climate, 25, 2146–2161, doi:

Kaniewski, D. et al., 2012, Drought is a recurring challenge in the Middle East, PNAS 109:10, 3862–3867, doi: 10.1073/pnas.1116304109

Kaniewski, D. et al., 2013, “Environmental Roots of the Late Bronze Age Crisis,” PLOS one, DOI: 10.1371/journal.pone.0071004

Kelley, C.P. et al., 2016, “Climate change in the Fertile Crescent and implications of the recent Syrian drought,” PNAS vol. 112 no. 11, 3241–3246, doi: 10.1073/pnas.1421533112

Ortloff, C.R. and A.L. Kolata, 1992, “Climate and Collapse: Agro-Ecological Perspectives on the Decline of the Tiwanaku State,” J. of Archaeological Science 1992, 195-221.

Wendel, JoAnna, 2015, Chinese Cave Inscriptions Tell Woeful Tale of Drought,” EOS, 1 October 2015.

Yancheva, G. et al., 2007, “Influence of the intertropical convergence zone on the East Asian monsoon,” Nature 445, 74–77 (2007).