A new NASA -led study has revealed that the drought the Middle East has recently experienced is highly likely to be the worst it has seen in 900 years and was contributed to by climate change.

The researchers behind the study concluded that the 15 year drought, which started in 1998 in the Levant – including Lebanon, Jordan, Palestine and Syria, is the driest in the last 900 years.

"There is an 89 percent likelihood this drought is drier than any comparable period of the last 900 years and a 98 percent likelihood it is drier than the last 500 years," the researchers said in the study, which was published in the Atmospheres section of the Journal of Geophysical Research.

To reach their conclusions, the researchers analyzed 900 years of Mediterranean drought variability in a record known as the Old World Drought Atlas. The record uses the rings of trees to reconstruct the patterns of drought across a geographical region over time.

Tree rings were sampled from a large portion of the Mediterranean region, including North Africa, Greece, Lebanon, Jordan, Syria and Turkey. They were then analyzed with tree-ring records from Spain, southern France and Italy.

The researchers stated that the findings from their Levant analysis confirm the Middle Eastern drought's exceptional nature compared with the natural variability in recent centuries.

In addition, they found them to be consistent with evidence for human-induced drying in the region. "This offers independent support for recent studies concluding that anthropogenic climate change has had a significant influence," the researchers stated.

"The magnitude and significance of human climate change requires us to really understand the full range of natural climate variability," said Ben Cook, the study's lead author and climate scientist at NASA's Goddard Institute for Space Studies, according to NASA's press release .

"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."

Moreover, Cook and his co-authors have also stated that the drought conditions in the Middle East are probably going to worsen in the future, due to "climate change amplifying the potential for sociopolitical and economic disruption."

"Dealing with the consequences of aridification for societies and ecosystems in the region will require a multidisciplinary research, management, and policy approach," concluded the study.