"Long before it's in the papers"
March 02, 2015


Study links war, global warming for first time—in Syria

March 2, 2015
Courtesy of PNAS
and World Science staff

Re­search­ers have pub­lished the first ma­jor study to draw a link be­tween glob­al warm­ing and on­go­ing civ­il un­rest or war.

The study sug­gests a link be­tween glob­al warm­ing-related cli­mate trends and se­vere drought in the Fer­tile Cres­cent re­gion that pre­ced­ed civ­il un­rest in Syr­ia. How­ev­er, the re­port al­so points to farm­ing prac­tices as a fac­tor ex­ac­er­bating the dry con­d­i­tions.

The Fertile Crescent (green), a region sometimes called the cradle of civilization. A study sug­gests a link be­tween glob­al warm­ing-related cli­mate trends and se­vere drought in the re­gion, pre­ced­ing civ­il un­rest in Syr­ia. (Map by Rob­ert Sim­mon, cour­tesy NA­SA Earth Ob­serv­a­tory)

The Fer­tile Cres­cent is a quar­t­er-moon-shaped zone of rel­a­tively moist and fer­tile land that in­cludes what are to­day large parts of Iraq and Syr­ia. 

Syr­i­a’s on­go­ing in­ter­nal con­flict be­gan in 2011, fol­low­ing three years of the most se­vere drought recorded in the re­gion, sci­en­tists said. 

To in­ves­t­i­gate the drought’s causes, Col­in P. Kel­ley of the Uni­vers­ity of Cal­i­for­nia, San­ta Bar­ba­ra and col­leagues ex­am­ined century-long trends in pre­cipita­t­ion, tem­per­a­ture, and sea-level air pres­sure in the re­gion. 

Their find­ings are pub­lished in this week’s early on­line is­sue of the re­search jour­nal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­en­ces.

The in­ves­ti­ga­tors con­clud­ed that the re­cent de­crease in rain­fall in Syr­ia is likely part of a long-term dry­ing trend, linked with in­creas­ing sea-level pres­sure in the east­ern Med­i­ter­ra­nean Sea. Both these trends were ac­com­pa­nied by warm­ing, and the dry­ing and warm­ing trends were con­sist­ent with sim­u­lat­ed cli­mate re­sponses to green­house gas-related cli­mate warm­ing, ac­cord­ing to Kel­ley and col­leagues.

NASA image show­ing drought cond­i­tions in 2007-2008, short­ly be­fore the Syr­ian un­rest be­gan.

Releases of those gases into the atmo­sphere are blamed for glo­bal warm­ing.

Farming prac­tices pri­or to the drought likely con­tri­but­ed to ground­wa­ter de­ple­tion, and the drought was fol­lowed by ag­ri­cul­tur­al col­lapse and in­ter­nal dis­place­ment of up to 1.5 mil­lion peo­ple who moved from ru­ral farm­land to ur­ban cen­ters, ac­cord­ing to the re­search­ers. They add that the re­sults sug­gest links among drought, glob­al warm­ing-related cli­mate trends, and the Syr­i­an un­rest.

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Researchers have published the first major study to draw a link between global warming and ongoing civil unrest or war. The study suggests a link between global warming-related climate trends and severe drought in the Fertile Crescent region that preceded civil unrest in Syria. However, the report also points to farming practices as a factor in exacerbating the drought. The Fertile Crescent is a quarter-moon-shaped zone of relatively moist and fertile land that includes what are today large parts of Iraq, Syria and Jordan. Syria’s ongoing internal conflict began in 2011, following three years of the most severe drought recorded in the region, scientists said. To investigate the drought’s causes, Colin P. Kelley of the University of California, Santa Barbara and colleagues examined century-long trends in precipitation, temperature, and sea-level air pressure in the region. Their findings are published in this week’s early online issue of the research journal pnas. The investigators concluded that the recent decrease in rainfall in Syria is likely part of a long-term drying trend, linked with increasing sea-level pressure in the eastern Mediterranean Sea. Both these trends were accompanied by warming, and the drying and warming trends were consistent with simulated climate responses to greenhouse gas-related climate warming, according to Kelley and colleagues. Agricultural practices prior to the drought likely contributed to groundwater depletion, and the drought was followed by agricultural collapse and internal displacement of up to 1.5 million people who moved from rural farmland to urban centers, according to the researchers. They add that the results suggest links among drought, global warming-related climate trends, and the onset of the Syrian unrest.