Nearly 1,000 feet below the bed of the Dead Sea, scientists have found evidence that during past warm periods, the Mideast has suffered drought on scales never recorded by humans—a possible warning for current times. Thick layers of crystalline salt show that rainfall plummeted to as little as a fifth of modern levels some 120,000 years ago, and again about 10,000 years ago. Today, the region is drying again as climate warms, and scientists say it will get worse. The new findings may cause them to rethink how much worse, in this already thirsty and volatile part of the world. “All the observations show this region is one of those most affected by modern climate change, and it’s predicted to get dryer. What we showed is that even under natural conditions, it can become much drier than predicted by any of our models,” said lead author Yael Kiro, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory. The findings were just published in an early online edition of the journal Earth and Planetary Science Letters. The landlocked Dead Sea, straddling Israel, Jordan and Palestinian lands, is earth’s lowest spot on land. Its current shoreline lies about 1,300 feet below sea level, and its floor extends down another 900 feet. Fed mainly by the Jordan River drainage, which extends also into Syria and Lebanon, it is a dead end for water, and so is extremely salty; its Biblical name in Hebrew is Yām ha-Melah, the sea of salt. In recent years, its level has dropped about four feet a year. But hot, dry weather is not the main cause yet; rather, booming populations in the region need more water than ever, and people are sucking so much from the watershed, very little reaches the…