NASA: Turkey suffering worst drought in 900 years

The official NASA website explained that Ben Cook, lead author and climate scientist at the organization's Goddard Institute for Space Studies and the Lamont Doherty Earth Observatory at Columbia University stated, "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."
According to NASA, the scientists there 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.
Scientists found droughts in the tree ring record between the years 1100 and 2012 which corresponded to those described in historical documents. Cook explained that the range of how extreme wet or dry periods were is quite broad, but the recent drought in the Levant region, from 1998 to 2012, stands out as about 50 percent 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.