A new NASA study has found that the drought which began in 1998 in the eastern Mediterranean Levant region, comprising Cyprus, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey, is likely the worst one in the past 900 years.
According to NASA, scientists reconstructed the Mediterranean’s drought history by studying tree rings as part of an effort to understand the region’s climate and what shifts water to or from the area. Thin rings indicate dry years while thick rings show years when water was plentiful.
In addition to identifying the driest years, the science team discovered patterns in the geographic distribution of droughts that provides a “fingerprint” for identifying the underlying causes. Together, these data show the range of natural variation in Mediterranean drought occurrence, which will allow scientists to differentiate droughts made worse by human-induced global warming.
Ben Cook, lead author and climate scientist at NASA’s Goddard Institute for Space Studies and the Lamont Doherty Earth Observatory at Columbia University in New York City said: “If we look at recent events and we start to see anomalies that are outside this range of natural variability, then we can say with some confidence that it looks like this particular event or this series of events had some kind of human caused climate change contribution,” he said.
Between the years 1100 and 2012, the team found droughts in the tree-ring record that corresponded to those described in historical documents written at the time. According to Cook, the recent drought in the Levant, from 1998 to 2012, stands out as about 50 per cent drier than the driest period in the past 500 years, and 10 to 20 percent drier than the worst drought of the past 900 years.
Such droughts had the potential to cause large-scale disruption of food systems as well as potential conflict over water resources. “The Mediterranean is one of the areas that is unanimously projected [in climate models] as going to dry in the future [due to man-made climate change],” said Yochanan Kushnir, a climate scientist at Lamont Doherty Earth Observatory, who was not involved in the research.
The results of the study were accepted for publication in the Journal of Geophysical Research-Atmospheres.