Natural disasters as push-pull factors Summary

  • Last updated on November 10, 2022

Permanent or temporary migration to a safer environment is the traditional survival strategy of populations faced with overwhelming natural or environmental disasters. Often such disasters not only result in destruction of living environments, but also destroy the social and economic fabrics of a society, forcing entire communities to seek new social, economic, and cultural environments in which to thrive.

Natural disasters often function as initiatives to push populations to migrate to new, more favorable living conditions. Less frequently, areas struck by natural disasters may serve to pull in small group populations if they believe the post-disaster living conditions can be exploited to their advantage. A broad and extensive record of migrations, both forced and voluntary, exists in the geological, archeological, and written historical records documenting human culture.Natural disastersEmigration;and natural disasters[natural disasters]Push-pull factors[push pull factors];natural disastersNatural disastersEmigration;and natural disasters[natural disasters]Push-pull factors[push pull factors];natural disasters[cat]PUSH-PULL FACTORS;Natural disasters as push-pull factors[03770][cat]ECONOMIC ISSUES;Natural disasters as push-pull factors[03770]

Disasters and Historical Migrations

Evidence exists suggesting environmental change initiated the first humanoid migrations out of the African continent as early as 60 to 70 millennia in the past, dispersing human ancestry northward in an attempt to find more favorable living conditions. Geological evidence from about 70 millennia ago indicates that a super-volcanic eruption of the Lake Toba Caldera on the Indonesian island of Sumatra resulted in a massive climate-changing event. The dating of this eruption coincides with fossil evidence and Deoxyribonucleic acidDNA indexing suggesting that a massive reduction in the human population of the time from estimates of 60 million to as few as 10,000 survivors globally. The resulting bottlenecking of human evolution precipitated an outward radiation of survivors to new habitats.

In much more recent times, a massive flooding of the Black Sea through the Bosporus Straits around 5600 b.c.e. devastated the near-shore cultures and resulted in a mass migration out of the area populating new regions of Asia Minor. This flood was mythologized in both the Tale of Gilgamesh and the biblical Book of Genesis. More recently still, the super-volcanic eruption of the Santorini Caldera in the southern Aegean Sea around 1600 b.c.e. caused the downfall of the Minoan and other Bronze Age cultures, and the climatic outfall from the eruption severely stressed Egyptian and early Greek cultures. Survivors of the eruption dispersed throughout the Mediterranean basin to repopulate new territories and give rise to new cultures. In North and South America, inclusive evidence has linked droughts caused by climatic changes to the collapse and migration of native cultures, including the ancient Pueblo peoples of the American Southwest, the Maya and Olmec peoples of Mexico and Central America, and the Nazca culture of the South American Andes.

Disaster-Driven Migrations to North America

During the late tenth century, the VikingsVikings of northern Europe were pushed to explore and settle North America after their colonies had deforested Greenland. However, they had to abandon their North American colonies when the Little Ice AgeLittle Ice Age developed and new Arctic ice floes blocked sailing routes. The Little Ice Age, which lasted from the mid-thirteenth to the early seventh centuries, worked as a major push-pull factor in human migrations. Cooling in the northern hemisphere resulted in severe long-term crop losses, food shortages, and prolonged famines. It also led to the outbreak of numerous diseases, most notably the Plaguebubonic plague. The freezing of shipping lanes devastated trade. Sustained droughts ensued, forests were cut down for heating fuel, and warfare became almost constant among communities competing for shrinking resources. All these conditions resulted in massive disruptions of social and cultural systems.

Victims of the 1918 influenza pandemic in a Kansas emergency hospital.

(AP/Wide World Photos)

Northern European and Asian peoples migrated to escape the harsh climatic conditions or to fill living niches left by deaths and emigration. By the late fifteenth century, the need to search out resources and flee social upheavals gave rise to an era of exploration. Over the next several hundred years, large numbers of Europeans were pushed and pulled into emigrating to North America.

During the mid-nineteenth century, two large-scale famines proved major push factors in North American immigration: the Great Irish FamineGreat Irish Famine between 1845 and 1852, and the Great Northern China Famine of 1877-1878. Survivors of both famines were pushed out of their homelands by the deteriorating economic and social conditions, and pulled to the prospects of a better life in North America. In the same manner, during the late twentieth century, severe drought, desertification, and famine resulted in large migrations of peoples from central and sub-Saharan Africa. As global climate changes have continued to advance during the twenty-first century, rising sea levels, climatic variations, and habitat loss will most likely bring about major new population migrations in the future.

Disaster-Driven Migrations Within North America

An early twentieth century disaster that directly affected North America was the great Influenza;pandemicinfluenza pandemic of 1918-1919, in which more than 500 million people were infected and 100 million died worldwide, mostly young adults. Between 700,000 and 1 million people are estimated to have died from influenza within the United States. Influenza deaths became a pull factor that drew people to migrate to new regions to fill jobs and properties previously held by influenza victims. Another early twentieth century disaster that prompted a massive internal migration was the Mississippi River;Great FloodGreat Mississippi Flood of 1927, in which more than 700,000 persons were displaced from their homes. It helped propel the Great Migration of African Americans;Great Migration ofAfrican Americans from the South to northern cities, particularly Chicago and Detroit.

The disastrous North American hurricane season of 1928, while devastating vast areas of southern Florida, became a pull for migration as rebuilding efforts promoted the region as a vacation destination. The Dust BowlDust Bowl years of the 1930’s, brought on by poor farming practices and drought, pushed people from the Great Plains to northern cities and West Coast states.

In 2005, Hurricane KatrinaHurricane Katrina destroyed large portions of Louisiana, Mississippi, and Alabama;Hurricane KatrinaAlabama, most notably the city of New Orleans;Hurricane KatrinaNew Orleans. The hurricane resulted in the evacuation of more than 1,000,000 people, the largest migration of Americans since the Dust Bowl years. Of these people, 700,000 became displaced persons from New Orleans, and after two years only 40 percent had returned home; the remaining number relocated to other cities throughout the United States. On a smaller scale, a tornado in Oklahoma;Picher tornadoPicher, Oklahoma, in 2008 resulted in the town being destroyed to such an extent it was abandoned in 2009, forcing all its residents to migrate to new locations.Natural disastersEmigration;and natural disasters[natural disasters]Push-pull factors[push pull factors];natural disasters

Further Reading
  • Bullard, Robert D., and Beverly Wright, eds. Race, Place, and Environmental Justice After Hurricane Katrina. Boulder, Colo.: Westview Press, 2009. Revealing look at the roles of different ethnic communities in the rebuilding of the Gulf coast after Hurricane Katrina struck.
  • Clark, Jeffrey J. Tracking Prehistoric Migrations: Pueblo Settlers Among the Tonto Basin Hohokam. Tucson: University of Arizona Press, 2001. Of the migrations of early Native American groups in the American Southwest.
  • Diamond, Jared. Guns, Germs, and Steel. New York: W. W. Norton, 1997. Extended essay on world history offering many ideas on how physical geography has influenced human events such as population movements.
  • Fagan, Brian. The Little Ice Age: How Climate Made History, 1300-1850. New York: Basic Books, 2000. Interesting study of the relationship between climatic changes, food supply, and population movements during the Little Ice Age.
  • Gregory, James N. American Exodus: The Dust Bowl Migration and Okie Culture in California. New York: Oxford University Press, 1989. History of the migrants from Oklahoma and other southern Great Plains states who fled to California to escape the Dust Bowl conditions of the 1930’s.
  • Gribben, Arthur, ed. The Great Famine and the Irish Diaspora in America. Amherst: University of Massachusetts Press, 1999. Collection of twelve essays commemorating the 150th anniversary of the Great Irish Famine that drove more than 1.5 million people to leave Ireland.
  • Levey, Richard, and Daniel Franck. Dust Bowl! The 1930’s Black Blizzards. New York: Bearport, 2005. Graphic account of the effects of dust storms in the Midwest.
  • Rain, David. Eaters of the Dry Season: Circular Labor Migration in the West African Sahel. Boulder, Colo.: Westview Press, 1999. Encroaching desertification has made West Africa’s Sahel region one of the most precarious human environments in the world. This work explores the dynamics of the population that lives in the Sahel, from the seasonal migrants to the farmers and herders.
  • Rosario, Kevin. The Culture of Calamity: Disaster and the Making of Modern America. Chicago: University of Chicago Press, 2007. Broad survey of the role of natural disasters in U.S. history.
  • Williams, A. R. “After the Deluge: Central America’s Storm of the Century.” National Geographic, November, 1999, 108-129. Well-illustrated account of Hurricane Mitch, which devastated Central America in 1998 and drove tens of thousands of people to emigrate to the United States.

Disaster recovery work

Economic opportunities

Great Depression

Great Irish Famine

Mississippi River

Push-pull factors


Return migration

Salvadoran immigrants

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