Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 12:54 PM GMT on June 18, 2014
Syria's devastating civil war that began in March 2011 has killed over 200,000 people, displaced at least 4.5 million, and created 3 million refugees. While the causes of the war are complex, a key contributing factor was the nation's devastating 2006 - 2011 drought, one of the worst in the nation's history, according to new research accepted for publication in the journal Weather, Climate, and Society by water resources expert Dr. Peter Gleick of the Pacific Institute. The drought brought the Fertile Crescent's lowest 4-year rainfall amounts since 1940, and Syria's most severe set of crop failures in recorded history. The worst drought-affected regions were eastern Syria, northern Iraq, and Iran, the major grain-growing areas of the northern Fertile Crescent. In a press release that accompanied the release of the new paper, Dr. Gleick said that as a result of the drought, "the decrease in water availability, water mismanagement, agricultural failures, and related economic deterioration contributed to population dislocations and the migration of rural communities to nearby cities. These factors further contributed to urban unemployment, economic dislocations, food insecurity for more than a million people, and subsequent social unrest."
Figure 1. The highest level of drought, "Exceptional", was affecting much of Western Syria in April 2014, as measured by the one-year Standardized Precipitation Index (SPI). Image credit: NOAA's Global Drought Portal.
Human-caused climate change a major factor in more frequent Mediterranean droughts
The paper also assessed the role of climatic change in altering water availability. There is growing evidence that annual and seasonal drought frequency and intensity in the Levant/Eastern Mediterranean region have increased from historical climatic norms, with the number of dry days increasing during the winter rainy season. Similar findings were discussed in a NOAA press release that accompanied the release of a 2011 paper by Hoerling et al., "On the Increased Frequency of Mediterranean Drought." That paper found that human-caused emissions greenhouse gases were "a key attributable factor" in the drying up of wintertime precipitation in the Mediterranean region in recent decades.
Figure 2. Winter precipitation trends in the Mediterranean region for the period 1902 - 2010. In the 20 years ending in 2010, 10 of the driest 12 winters took place in the lands surrounding the Mediterranean Sea. Image credit: NOAA.
Future conflict over water in the Middle East
The potential for future conflict in the Middle East over water is significant. Researchers Heidi Cullen and Peter deMenocal discussed previous incidents in 1975 and 1990: Turkey, because it has the good fortune of being situated at the headwaters of the Tigris – Euphrates River system, can literally turn off the water supply of its downstream neighbors. When the Ataturk Dam was completed in 1990, Turkey stopped the flow of the Euphrates entirely for 1 month, leaving Iraq and Syria in considerable distress. Similarly, in 1975, when the Syrians began filling Lake Assad after completion of work on the Tabqa Dam, Iraq threatened to bomb the dam, alleging that it seriously reduced the river’s flow. Both countries amassed troops along the border.
Figure 3. Stele of Narâm-Sîn, king of the Akkadian Empire, celebrating his victory against the Lullubi from Zagros. Limestone, c. 2250 BCE, Louvre Museum. Image credit: Marie-Lan Nguyen
A great Syrian drought 4,200 years ago
Great civilization-threatening droughts have happened before in Syria. In a 2000 article published in Geology, "Climate change and the collapse of the Akkadian empire: Evidence from the deep sea", a team of researchers led by Heidi Cullen studied deposits of continental dust blown into the Gulf of Oman in the late 1990s. They discovered a large increase in dust 4,200 years ago that likely coincided with a 100-year drought that brought a 30% decline in precipitation to 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 Akkadian Empire, which flourished in ancient Mesopotamia between 2334 BC - 2193 BC, also crashed at this time, giving credence to the idea that the drought may have been a key reason why. The 4.2 kiloyear event has also been linked to the collapse of the Old Kingdom in Egypt. 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."
People fear storms, and spectacular and devastating storms like Hurricane Sandy and Hurricane Katrina have stirred more debate in the U.S. about taking action against climate change than any other weather events. But I argue that the on-going Western U.S. mega-drought and Syrian drought should be louder wake-up calls. Drought is the greatest threat civilization faces from climate change, because drought takes away the two things necessary to sustain life--food and water. Drought experts Justin Sheffield and Eric Wood of Princeton, in their 2011 book, Drought, list more than ten civilizations and cultures that probably collapsed, in part, because of drought. Among them: The Mayans of 800 - 1000 AD. The Anasazi culture in the Southwest U.S. in the 11th - 12th centuries. The ancient Akkadian Empire in Mesopotamia. The Chinese Ming Dynasty of 1500 - 1730. 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. The fact that the most politically volatile region on the planet is already experiencing an increase in drought that research links to climate change should be a serious wake-up call about the need to manage water resources more wisely--and to work to forge an international agreement in Paris in 2015 to cut down on the amount of heat-trapping carbon dioxide humans are putting into the air. Dr. Gleick's paper concludes with sensible options for reducing the risks of water-related conflicts in the Middle East, including expansion of efficient irrigation technologies and practices, integrated management and monitoring of groundwater resources, and diplomatic and political efforts to improve the joint management of shared international watersheds and rivers.
Gleick, P., 2014, Water, Drought, Climate Change, and Conflict in Syria, accepted for publication in Weather, Climate, and Society
Cullen, H.M., and P.B. deMenocal, 2000, North Atlantic Influence on TIgris-Euphrates Streamflow, International Journal of Climatology, 20: 853-863.
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: http://dx.doi.org/10.1175/JCLI-D-11-00296.1
Kaniewski, D. et al., 2012, Drought is a recurring challenge in the Middle East, PNAS 109:10, 3862–3867, doi: 10.1073/pnas.1116304109
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