家园纪录片第19期

500 million humans live in the world's desert lands, more than the combined population of Europe. They know the value of water.

They know how to use it sparingly. Here, they depend on wells replenished by fossil water.

Which accumulated underground in the days when it rained on these deserts. 25,000 years ago.

Fossil water also enables crops to be grown in the desert to provide food for local populations. The fields' circular shape derives from the pipes that irrigate them around a central pivot.

But there is a heavy price to pay. Fossil water is a nonrenewable resource.

In Saudi Arabia, the dream of industrial farming in the desert has faded. As if on a parchment map, the light spots on this patchwork show abandoned plots.

The irrigation equipment is still there. The energy to pump water also.

But the fossil water reserves are severely depleted. Israel turned the desert into arable land.