7: The Rain Follows the Plow

If only it were so easy. It's actually kind of shocking that humanity held on to the idea that land would become fertile through farming for so long. Didn't anyone look around and see that all this farming of arid land wasn't doing much?

So much for observation.

In reality, this quite erroneous theory (popular during the American and Australian expansions) may have stayed alive in part because it did sometimes work -- or at least it seemed to work.

What we know now is that the plow wasn't actually bringing the rain; long-term weather patterns were. Arid regions (like the American West, for example) go through long-term cyclical droughts, followed by cycles of wetter years. Wait long enough and you'll get a few wet ones.

There's just one problem: wait a few more years and all the rain just goes away - only now, you've got a civilization to support.

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