A recent study on droughts in the Middle East shows that the recent droughts that have plagued the area are the worst in at least 1100 years, according to a story this week in the American Geophysical Union blog. The scientists in the study collected a stalagmite from a cave in Iraq which contained growth rings that traced the rise and fall of precipitation in the area. Using isotope dating they were able to determine the first ever detailed climate reconstruction for the eastern part of Middle East’s most important region for agriculture – the Fertile Crescent – extending back 2,400 years. The research showed the recent droughts are the most severe going back to about 1,1o0 years ago. You can read more about how they did the study at http://blogs.agu.org/geospace/2017/02/16/ancient-cave-reveals-recent-droughts-middle-east-severe-millennium/.
If you are interested in how they do the radiocarbon analysis, this article from EarthSky might be helpful: http://earthsky.org/earth/what-is-radiocarbon-dating?mc_cid=b855723a0c&mc_eid=b22da16cce.