A Great Vanishing Sea

New satellite images from NASA show that the Aral Sea, a once-vast lake on the border of Kazakhstan and Uzbekistan, has almost completely dried up. At first glance, the sea looks like another victim of climate change, but in fact its depletion originated in ill-considered Soviet agricultural policies:

Actually a freshwater lake, the Aral Sea once had a surface area of 26,000 square miles (67,300 square kilometers). It had long been been ringed with prosperous towns and supported a lucrative muskrat pelt industry and thriving fishery, providing 40,000 jobs and supplying the Soviet Union with a sixth of its fish catch. The Aral Sea was fed by two of Central Asia’s mightiest rivers, the Amu Darya and the Syr Darya.

But in the 1960s, Soviet engineers decided to make the vast steppes bloom. They built an enormous irrigation network, including 20,000 miles of canals, 45 dams, and more than 80 reservoirs, all to irrigate sprawling fields of cotton and wheat in Kazakhstan and Uzbekistan. But the system was leaky and inefficient, and the rivers drained to a trickle. In the decades that followed, the Aral Sea was reduced to a handful of small lakes, with a combined volume that was one-tenth the original lake’s size and that had much higher salinity, due to all the evaporation.

Anna Nemtsova explains how the events of the past decade finished it off:

The final chapter began in 2005, when the World Bank gave Kazakhstan the first $68 million credit to build a 13-kilometer-long dam to split the Aral Sea into halves: the Northern Aral Sea in Kazakhstan and the Southern Aral Sea in Uzbekistan. The dam prevented water from Kazakhstan’s Syr Darya from flowing into Uzbekistan’s half of the sea.

By 2008, Kazakhstan had managed to complete take control over the Syr Darya water, reviving 68 percent of the northern sea, reducing the salinity by half, and once again developing the fishing industry. On the southern, Uzbek side, however, the sea dried up that much faster. Uzbekistan, largely dependent on cotton, the industry of white gold, could not afford to re-channel water to its half. Also, with the water vanishing, the Russian oil company Lukoil found a silver lining in the disaster, setting out in 2006 to explore for oil and gas on the bottom of the Aral Sea in the Uzbek sector.

While climate change is not primarily responsible for the shrinking sea, it’s making the problem worse:

Recent studies suggest only 14% of the shrinking of the Aral Sea since the 1960s was caused by climate change, with irrigation by far the biggest culprit. Researchers looking at what will happen to Aral Sea levels with global warming over the next few decades have combined several model predictions together and expect net water loss to increase as more evaporation leads to less river inflow. However, if irrigation of the rivers continues, then net water loss will be even greater as river flow into the Aral Sea will essentially cease.