Water With Care

Part of the Water: H2O = Life exhibition.

© iStockPhotoField Irrigation

Sucked Dry by Cotton

Human civilization as we know it would not exist without irrigation. For thousands of years, cultures around the world have developed technologies to store water in reservoirs and deliver it to farms using ditches and canals. Today, 40 percent of the world's food is grown in areas where irrigation is necessary—where crops wouldn't flourish with rainfall alone. And by using irrigation, some farmers can raise two or even three crops each year instead of only one.

Irrigation solves many problems, yet it creates others when used unwisely. To produce food for growing populations, people have diverted rivers and destroyed ecosystems to irrigate large-scale farms. We waste water, and the energy needed to pump it, by growing thirsty crops in deserts. What's more, the use of pesticides and fertilizers contaminates precious sources of fresh water.

Smarter Solutions

Only plant crops that can be grown within the limits of the nearby water supply.

NASA/UNEPUN Exhibition, Aral Sea 1973
NASA/UNEPAral Sea 2004

Sucked Dry by Cotton

Growing cotton requires tremendous amounts of water, so it's usually grown in wetter climates. Yet some central Asian farmers grow vast fields of cotton in the middle of a desert, diverting water from the rivers that feed the Aral Sea. Today, along the sea's former shores, rusted fishing boats sit near abandoned villages and piles of poisonous dust and salt. Children there are at higher risk for many health problems, some likely caused by cotton pesticides. And the region has lost dozens of bird and fish species. Kazakhstan has begun projects to restore the northern part of the sea-irrigating crops more efficiently and building dikes. But if a more complete restoration is possible, it will take even greater effort over many decades.

Central Asia's leading cotton producer, Uzbekistan, grew more than one million metric tons of cotton in 2003

A Shrinking Sea

Once the world's fourth largest body of fresh water, the Aral Sea lost 75 percent of its volume and more than half of its surface area between 1973 and 2004 as a result of cotton farming.