In a series of dramatic photos, NASA has been able to capture the disappearance of the Aral Sea from space. In the 1960's Russia diverted water from several major rivers to irrigation projects for growing cotton and other crops. The result has been the complete destruction of one what was once the fourth largest inland sea in the world.
NASA's ability to document this entirely unprecedented event is not only fascinating, but it's a lesson to how quickly entire ecosystems (and the societies that rely on them) can collapse. The Aral sea was once surrounded by villages that relied on the Aral seas fisheries. Those towns are now all but deserted, and fishing boats sit on dry land.
Next time some nutjob tells you that humanity is too insignificant to really destroy the environment in significant ways, just send them to this page.