The Aral Sea was the fourth largest lake in the world until the 1960s, when the Soviet Union diverted water from the rivers that fed the lake so cotton and other crops could be grown in the arid plains of Kazakhstan, Uzbekistan and Turkmenistan. The black outline shows the approximate coastline of the lake in 1960. By the time of the 2000 image, the Northern Aral Sea had separated from the Southern Aral Sea, which itself had split into eastern and western lobes. A dam built in 2005 helped the northern sea recover much of its water level at the expense of the southern sea. Dry conditions in 2014 caused the southern sea’s eastern lobe to dry up completely for the first time in modern times. The loss of the moderating influence of such a large body of water has made the region’s winters colder and summers hotter and drier.