Reuters: People in the Arab world need fuller and freer information about shrinking water supplies but their governments are withholding it for fear of fuelling unrest, a United Nations expert said on Thursday. Arable land makes up just 4.2 percent of the Middle East and North Africa and is expected to shrink due to climate change — a potential source of political instability, analysts say, in a region where economic privation has sometimes sparked conflict. “Arab countries do not …